Crystal Ball Volume 25 - Spring 2014

NEw zEALAND MOUNTAIN SAFETY COUNCIL

PERIODICAL OF ThE NEw zEALAND AVALANChE COMMUNITY

vOLUME 25 SPRING 2014

PHOTO: JAMIE ROBERTSON

g n i b m i e l r c u t fea www.avalanche.net.nz www.mountainsafety.org.nz www.adventuresmart.org.nz www.incidentreport.org.nz CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

DISCOVER MORE, SAFELY 1

CONTENTS 01 02 04 • • • • 12 • • • 23 • • • • • • 37 • • 59 61 63

Welcome Convenor’s Corner Snow & Avalanche Committee(SAC) ISSW & IKAR news new products education accident/incident summary 2014 Climbing Feature White matter - P.Goddard Mountaineers & avalanches - A.Uren Personal reflection - G.Gabites Research Airbag update - P.Haegeli Positive avalanches - H.Purdie Brewster glacier climatology - N.Cullen A tool for risk forecasting - M.Katurji Projecting future snow cover - A.Jobst Visualising avalanche paths - S.Morris Avalanche.net.nz Statistics Regional forecaster summaries 2014 NIWA winter climate summary Ski Patrol Training in New Zealand Case Study - ‘Walking the line’ - R.Leong

The Crystal Ball Volume 25, Spring 2015 Editor: Gordie Smith Executive Editor: Ian Owens Designer: Gordie Smith Cover Photo Credit: Jamie Robertson - Jane Morris breaking trail on the Linda Glacier Thank you to the contributors for giving permission to reproduce their material.

Copyright © New Zealand Mountain Safety Council 2014.

All rights reserved.

All opinions expressed in this magazine are not necessarily those of the New Zealand Mountain Safety Council. While efforts are made to check facts are accurate, responsibility lies with the author.

Editorial and Advertising enquiries Do you have something to say or show? We would like articles relating to the professional avalanche industry, public avalanche safety, teaching tips, research papers, accounts of avalanche events, book and gear reviews, event listings, interviews, letters to the editor, and humorous stories related to avalanches.

We are also looking for winter mountain photography of avalanches, touring, terrain, skiing, snowboarding, active control work, backcountry recreation or avalanche awareness activities.

For more information please contact: Andrew Hobman Tel: +64 27 446 2626 Fax: +64 4 385 7366 Email: andrew.hobman@mountainsafety.org.nz To have your voice heard at the SAC committee, contact your industry representative, or email: manager@avalanche.net.nz

WELCOME

Hi and welcome to the spring edition of the 2014 Crystal Ball. It was another eventful winter packed with low snow, education courses, public outreach events, the Backcountry Avalanche Advisories and the Info-Ex. Winter was slow to start and the snowpack stayed shallow in many areas. A long, cold dry spell in the south of the country led to a weak faceted layer developing in the pack and this was responsible for a number of avalanche incidents and near misses. Fortunately there were no fatalities and generally the incidents were shared well through the Info-Ex. Over the winter we have had a number of opportunities to reflect on the MSC avalanche programme, the messages we are trying to communicate and audience that is receiving them. We understand that when it comes to making a risk based decision, people think and behave in largely different ways and so the kinds of information and interventions that will be effective will vary from person to person. This presents a challenge.

The avalanche fatality statistics show that climbers dominate at over 50% and that we need to understand why and what would make a difference. An opportunity arose in the Remarkables Mixed and Ice Climbing Festival, which attracted over 140 climbers of all abilities. This 3 day event mixes clinics, activities and competitions. To the organiser’s credit, they invited us to be part of the festival and give talks, classes and evening briefings. There were a wide range of alpinists with high climbing skills but varying avalanche risk management skills. It was challenging to package a relevant message or advice for this diverse group.

There is no simple sound-bite but we are looking forward to working together again next year.

I recently attended the International Snow Science Workshop (ISSW) where one common theme was a better understanding of how people make decisions and how this can be affected by risk communication, education and human factors. The evolving world of Behavioural Economics has many similarities as it measures the human decision making process and linking this learning continues to improve avalanche messaging and education.

Overall the New Zealand avalanche programme is tracking well against the European and North American programmes and we have the opportunity to work with them on a number of projects.

Over the summer we will be continuing to work on our risk communication challenge and assessing how we can do it better, including working with the groups that we are trying to communicate with to ensure that we are having the most effect.

Don’t forget the Southern Hemisphere Avalanche Conference in 12th -14th June 2015.

See you there or out in the hills.

Hobbie - Andrew ‘Hobbie’ Hobman, Avalanche and Alpine programme manager

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

1

Convenor’s corner

// making a difference

Ah, Spring…that time of year when the skis return to the back corner of the garage and my fingers make greater contact with the laptop keyboard than my gloves and poles.

It’s time to etch away at the small mountain of desk work that deposit in the lee of the winter season. Despite the tedium of year end reporting process, it does provide a tangible reminder of what’s been done, and how well. That reflection can provide the perfect springboard for future focus.

In conjunction with their representative organisations, some of the key outcomes that the Snow and Avalanche Committee (SAC) and the Avalanche Education Working Group (AWEG) have accomplished in the last year are: • • • • • • • •

Contributing to and establishing avalanche rescue protocol and standards Gathering and communicating avalanche information and conditions Contributing to industry best practice for heli-skiing, ski areas and outdoor instruction Encouraging and facilitating research in snow and avalanche related areas Contributing to the prevention of avalanche fatality/ injury Minimising sliding on snow accidents Contributing to and advancing avalanche education and recording standards Delivering avalanche education

Since backcountry use and population continue to grow, we believe that our prevention efforts are being rewarded in a very real way.

Some of our future goals in the coming year will focus around the Targeted review of qualification (TRoQ) avalanche education process and further development of pre-course learning materials that can be delivered on-line.

I hope you can also make the time to reflect on your season, look to ways you might be able to do it better and set your sites on some satisfying future goals.

As my mountain slowly erodes with each keystroke, the near future goals of surfing and ski touring grow ever closer. Always wary of false summits, I wont count my chickens just yet.

Enjoy your summer.

–Peter Bilous Snow and Avalanche Committee Convenor

Despite our efforts, during the last decade, statistics gathered from data collected by the New Zealand Mountain Safety Council, show that during an average year in New Zealand there will be 32 reported avalanche involvements, resulting in 22 people being caught, one of whom will die.

It should be noted that this figure is down from the NZ average 2.0 fatalities per year quoted in ICAR statistics for the period 1985/86-2000/01.

Snow and Avalanche Committee (SAC) The mission of MSC’s Snow and Avalanche Committee: To provide expert advice and support to the council on appropriate strategies to foster public safety in snow environments including: • Overseeing the training, assessments and qualifications of instructors to ensure that national standards are maintained and enhanced • Overseeing the professional training programmes of all providers as required • Monitoring, research and review trends in snow and avalanche activities to ensure the Council remains the leading authority for safety in this environment.

Convenor: Peter Bilous (Otago Polytech & AEWG rep) Members: Dr I Owens (University of Canterbury)

Dr N Cullen (University of Otago) Don Bogie (Department of Conservation) Arthur Tyndall & Nick Jarman (Club Ski Fields) Wayne Carran (Downer EDI Works) Andy Hoyle (SAANZ North Island) John Hooker (SAANZ South Island) Pete Zimmer (LandSAR) Kevin Boekholt (NZMGA) Andrew Hobman & Gordon Smith (NZMSC)

To have your voice heard at the SAC committee, contact your industry representative or email manager@avalanche.net.nz

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

2

2015

with guest speaker Karl Birkeland

12-14 june

CHRISTCHURCH NEW ZEALAND

current practice future thinking

The New Zealand Mountain Safety Council invites the avalanche sector - from senior management to frontline practitioners, to the bi-annual Southern Hemisphere Avalanche Conference.

The Conference consists of a full day of workshops, followed by a two day conference of informative presentations from New Zealand and international experts on the latest developments and current best practice in theory and research, management and mitigation and search and rescue.

Take the opportunity to meet, learn and share with the best minds in the industry, trial the latest gadgets and new technology, catch-up with friends and colleagues.

Registrations open soon.

If you would like to present at, or sponsor the conference please contact Andrew Hobman email andrew.hobman@mountainsafety.org.nz or telephone +64 27 446 2626 Expressions of interest for a presentation topic deadline is November 30, 2014.

Supported by:

CLICK ON THIS PAGE FOR MORE INFO AND REGISTRATION DETAILS CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

3

SAC - updates - rescue at 2014 issw and icar // don bogie

Don Bogie works for the Department of Conservation based in Christchurch and is a regular contributor to the Crystal Ball. In this article he summarises the key points he took from his recent attendance at two international conferences. dbogie@doc.govt.nz The International Snow Science Workshop (ISSW) was held in Banff in late September followed by the International Commission Alpine Rescue (ICAR or IKAR) which was held at Lake Tahoe. ISSW had a number of presentations devoted to avalanche rescue. The theme of IKAR was mass casualty incidents.

RESOURCES Previous ISSW papers can be found on line at http://www.issw.net/. ISSW 2014 papers should be there in the near future.

In the meantime you can read all ISSW papers referred to in this article via the links below (requires online pdf viewing): 1. IKAR Avalanche victim resucitation checklist 2. ISSW Case study of safe areas for Helicopter Landing Zones 3. ISSW Austrian survival time curve 4. ISSW Slalom probing 5. ISSW Recco training and use 6. ISSW Transceiver field lines The most important rescue item that appeared at ISSW and IKAR was avalanche victim survival information and the new IKAR field medical treatment card. The survival curve was referred to several times in IKAR presentations and has been calculated for Austrian data. The Austrian data Proctor (ISSW 2014) has produced similar results to the previous Swiss and Canadian studies showing the four phases.

1.

2.

3.

4.

Survival phase 0-18 min Asphyxia phase 18-35 min Latent phase 35-120 min Long term survival phase 120 min +

This paper reinforces the key messages of fast companion rescue and the need for high end medical care as part of organised rescue. Of particular note is that while survival chances drop off beyond 120 minutes a small percentage of buried victims do survive for a long time. This means that rescuers and those giving medical treatment need to be aware of that and take appropriate action. The IKAR medical commission has approved an avalanche victim resuscitation checklist to help buried victims receive the right care. A low quality copy can be viewed HERE or at Link 1 above. The approved version will be on the IKAR website in the near future. Use of this card will be introduced into New Zealand avalanche rescue training in 2015.

Other presentations of interest were: RECCO Genswein (ISSW 2014). The receive angle is narrower than previously thought so the search technique needs modifying. Many RECCO users have had problems with false signals caused through items of their own equipment. Strict protocols need following prior to searching to avoid finding yourself. This includes doing a self-check. Things like boot buckles and any metal or electronics the searcher has on them can cause issues. Heli searching with RECCO can be very effective but it is an advanced technique that needs careful initial set up, training by the searcher and pilot and the use of search protocols. Genswein has a free video on this See www.genswein.com

Dogs Testing in Europe Genswein (IKAR 2014) has shown that helicopters operating on site before search dogs arrive has no influence on the dogs search ability. The effect of snow compression and exhaust fumes were looked into. The aspect of helicopters that causes problems is machines hovering nearby while a dog is searching.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

4

SAC - updates - rescue at 2014 issw and icar conT’D // don bogie

Top: Banff National Park, Canada

Middle: Don Bogie, Dept of Conservation (right) discussing his poster presentation with a curious ISSW partipicant.

Left: Andrew Hobman, glad to be contributing a poster presentation at this years ISSW in Banff.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

5

SAC - updates - rescue at 2014 issw and icar conT’D // don bogie Transceivers There have been more improvements with new models. All manufacturers have new models with new features. One of the major changes is increased processor speed so that time lags in the display of direction and distance are reduced. There are physical limits of the radio frequency being used in transceivers that will limit any future large step improvements in what they can do. See Meier (ISSW 2014) if you want more technical detail and to see why the strongest signal on the surface is not always above the buried set. Interference of electronics and metal objects was looked at. Any metal object or electronics within 30 mm of a transmitting set will attenuate the signal which will make it harder to find. For this reason a separation of 20 cm is recommended to reduce the chances of something ending up close during an avalanche burial. This means no chest mounted go pros and care needs taking if wearing a radio with how the radio and transceiver are placed. For receiving a 50 cm separation with other objects is recommended. If possible turn off all electronics and put in your backpack. Large high tech watches can interfere so hold transceiver in your other hand. Definitely turn phones off while searching. It is the phones processor not its transmission that is the issue, so putting a phone into flight mode will not help. The key transceiver messages are; the newer three aerial sets are best, start probing early don’t waste time trying to be exact with the transceiver, searchers need to use three aerial sets to do effective triage and interference needs to be eliminated.

Slalom Probing The IKAR Avalanche Commission has a project to improve probe effectiveness. Genswein (ISSW 2014). This is being tested internationally at present including by the DOC Aoraki SAR team. It uses the same 50 cm x 50 cm pattern as we use now but changes the way probers move. All probing is done in front of body. The probe goes in upright but at 90 degrees to the snow surface. Instead of reaching to the side to do a probe the searcher moves to the side twice before moving forward. It is a technique for trained probers. Other points with it are the probe line leader probes from in the centre of line and no guidon cord is used. Depending on the outcome of the IKAR trials we will look to introduce the technique into training next winter.

Mass Causality Incidents (MCI) There were a number of presentations on this at IKAR. The best of them was from Mike Greene a doctor who is part of the medical commission and had been at Mt Hutt this year. The definition of a MCI is when there are more casualties than the local resources can normally handle. From an avalanche rescue perspective this does not need a lot of victims. MCI’s usually require the use of triage. With avalanche rescue this is a two-step triage situation. Firstly the search phase when resource allocation decisions are made aimed at maximising lives saved. This may mean not digging a deep burial out till after all others have been found. The second triage phase is with the medical treatment which is where the new IKAR field card is needed. MCI’s tend to have the following characteristics, they are relatively rare, while a number of them may happen in any one year individuals do not normally get to do lots of them, so there is often no institutional memory and people with experience move on. They are emotional events as they typically involve multiple fatalities and they generate huge public, media and political interest. A key point from the debrief of a mass casualty event on Mt Blanc was to protect the operational management component of the IMT from the pressures of media, politicians and the public interests so that they could continue to do their job.

MCI response needs planning, they need interagency organisation and practice. They need trust and familiarity between those likely to be involved. We should also never underestimate the size of the Incident Management Team (IMT) needed. They will need large IMT’s that are put in place fast. A good example of a New Zealand MCI exercise that involved interagency organisation and which built trust and familiarity between participants was operation Collaborate held near Pioneer Hut in June 2014.

See Exercise Collaborate June 2014 Southern Alps New Zealand on Vimeo. http://vimeo.com/108218407 or click the image at Right to launch in web browser.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

6

SAC - updates // editor southern hemisphere avalanche conference - SHAC Planning and preparations for next June’s avalanche conference are well under way. Ivitations for those wishing to present at this bi annual event are now open with prospective speakers needing to submit their expression of interest to Andrew Hobman by November 30.

Contact : andrew.hobman@mountainsafety.org.nz Karl Birkeland is coming from Montana, USA, and will be the Key note speaker. Many of you will know or have met Karl during his last visit to NZ a few years ago, and many more will have read his impressive collection of published papers.

Left: SHAC 2015 poster boy Stefan Austin (Treble Cone Ski Patrol) weaves a liquid line up the summit slopes for control work August 2014. Photo: G. Smith

new products - avatech snow probe & profiling tool Avatech - SP1 snow probe, Avanet snow profiling and sharing tool.

A team of engineers in America have developed a snow probe to automate the measuring of hand hardness.

The SP1 has been developed for the avalanche professional: snow safety teams at ski resorts, guides, avalanche forecasters, scientists, transportation departments, military, mines and more. This is NOT a recreational tool.

Data syncs from the SP1 to the AvaNet smartphone application via Bluetooth and then to the AvaNet web platform. Syncing between your smartphone and the web platform requires mobile data service or a wi-fi internet connection. You also have the option to transfer data directly from the SP1 via USB to your computer.

Click here to watch a video from the manufacture

Link to AVATECH products webpage for pricing and more details

Avatech have also developed ‘Avanet’ which is an internet cloud platform where you can draw, upload, and view others’ snowprofiles.

Some of the unique things about this Snowpit editor is the ability to draw your profile rather than filling in data boxes which then generate the graph (although you can do this too). You can grab and extend lines within the profile to adjust the graph.

Drag and drop layers and temperature, attach photos, visualize dangerous layers with highlighting of Yellow Flags, export to PDF and CSV and share and comment alongside SP1 profiles.

Try ‘Avanet’at no charge until 1/1/15

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

7

Sac - updates // editor Education The introduction last winter of a free online avalanche theory course continues to be very popular with over 1000 people working through this online resource. You can find the course here - ONLINE AVALANCHE COURSE A self marking quiz was also developed to test people’s understanding and help reinforce learning points. This has now been taken by 860 people. Those enrolled for the recreation level courses of Avalanche Awareness (AA is 1.5 days), and Backcountry (BC is 4 days) are given this online resource and quiz as ‘pre-course’ learning. Anecdotal evidence from course instructors show that overall, students came to courses with a more consistent base level of knowledge, making group management easier.

Above: Statistics of those who have done the online quiz Right: Screenshot of ‘Online Avalanche Course’

Recreational Courses

Avalanche course participant numbers comparisons

Attendance on the 4 day Backcountry course continues to grow, but as is often the case the Avalanche Awareness level courses react to what kind of winter we have had. After such a lean snow winter those numbers tappered off from what has been steady growth over the last few years.

Awareness AA

265

230

218

Canterbury was hit hardest with this downturn in attendance numbers, while courses run by external providers grew dramatically.

31

197

2012

2011

2012

33

26

22

2011

MSC Avalanche course participants 2011-2014

Backcountry BC

2013

2014

2013

2014

75

75

71 65

61 57

55

54 50

39 40

37

35

30

2828

26

12

11

9 0

00

BC

Tongariro

0

0

AA

0 0

BC

Taranaki

2

00

AA

6

0

BC

Canterbury

0 0

AA

Wanaka

9

0

BC

16

14

11

8

6

5

AA

36

6 0

AA

BC

Wakatipu

1112

10

00

AA

0 0

00

BC

Southland

8

4

AA

BC

External

Above: Recreational avalanche course particpant numbers by MSC Branch Region, and external providers.

Key: AA- Avalanche Awareness Course, BC - Backcountry Avalanche Course.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

8

Education continued Professional Courses Stage 1 The number of people enrolling for Avalanche Stage 1 this year bounced back up a little from last year’s figures. Short course participants grew at the expense of semester based courses. The increasing expense due to a lack of Tertiary Education Commission (TEC) funding for this course makes it difficult for providers to embed this course within larger programmes, and many are opting to run the more traditional short course format.

Combined NZ Polytechnics Stage 1 Participant numbers

2010

2011

2012

2013

2014

77

41

47

43

45 35

28

20

Stage 2 6 people passed their Stage 2 qualification this winter, and the other 2 participants have deferred passes requiring them to submit further evidence before gaining their certificate. This year’s intake of 8 participants is just under the last five yearly average of 9.

Short

Semester

Courses

Courses

17

15

Stage 2 graduate numbers 15

9

8 6

2009

2010

6

2011

2012

2013

2014

Above and Right: TPP Ski Patrol students practise their Stage 1 Avalanche skills while touring at the head of Wye Creek, September 2014.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

9

Sac - Accident/incident summary

-2014

// gordie smith

Assistant Avalanche programme manager New Zealand Mountain Safety Council

Based on data captured since 1996 by the New Zealand Mountain Safety Council, records show that during an average year in New Zealand there will be 32 reported avalanche involvements, resulting in 22 people being caught, 1 of whom will die.

This report details events and records from January 1 to October 1 2014. Unfortunately not all reports supplied complete details when recording avalanche involvements.

What we do know from the supplied data is that 19 events involved a total of 20 people, two of whom sustained knee injuries. All reported incidents were of people who either ended up on the surface of the snow (17) or were only partially buried with their head clear of the snow (3). There were no full burials, fatalities, or partial burials where the persons head was under snow.

The only female was a 25 year old snowboarder. All other incidents involved males ranging from 27 - 46 years old, and one dog (age unknown). Six events were recorded in each of the Canterbury and Southern Lakes regions, five in the Mackenzie region, and the remaining two occurring in the Tongariro region. Records show 8 events in July, 5 in August, and 6 during the month of September.

2014 Involvement statistics according to activity: Number of events Part or full burials Fatalities

Climbing

Ski Patrol Control Work

Ski/Board in Ski Area

Backcountry Ski

Backcountry Board

Heli Ski / Board

In Vehicles

Total

1

5

1

4

1

7

0

19

0

0

0

1

0

2

0

3

0

0

0

0

0

0

0

0

Notable facts from this winter’s data: There were many events that involved more than one person. This was the first winter in over a decade where the number of people being caught in avalanches was higher than the number of involvement events.

All of those who triggered and were caught in avalanches were 25 years or older, and predominantly males.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

10

Sac - Accident/incident summary -2014 conT’D // gordie smith Table: Long term trend summary Averages for years between: Total number of events reported Number of people caught Number of people killed

1996-2014

1996-2003

2004-2014

32.33 22.11 1.11

29.25 25.5 2.00

34.8 19.4 0.40

Encouragingly, the number of people being killed in avalanches over the past decade has more than halved from the previous period.

We believe that the NZMSC avalanche programme’s combined ‘Lighthouse’ effect has had a major influence helping steer people to make good decisions, and significantly reduce the number of people dying in avalanches.

Image below: Avalanche Programme Manager, Andrew Hobman’s 2014 ISSW poster presentation Click for larger image

Gaps in vital data fields make quantitative analysis tricky or impossible. It is critically important for evaluation, planning, development and saving lives that all near-misses, involvements and incidents are reported. Avalanche fatalities are our only complete dataset.

Prior to 2000, data had been collected primarily via a paper based process. Since the 2000 winter season, contributors have made increasing use of the online INFOEX system as their primary method of reporting. The INFOEX system has developed and changed over the years, as has the “New Zealand Guidelines for Weather, Snowpack and Avalanche Observations”.

There have always been inconsistencies in reporting frequency and habits, (NZMSC’s Crystal Ball reports - Irwin 2003, Hendrix 2006, Dignan 2007-2009), but it is hoped that with more opportunity, training and support, both the Public and Industry can record as full and accurate a data set as possible. NZMSC will continue to provide both on site and remote support to help achieve this.

One of the core principles of the recommendations by MBIE in the Tourism and Adventure Operations review is that: “Safety information is willingly exchanged externally. Exchange of safety information: organisations make a conscious and formalised effort to share safety information (including lessons learned) with others while externally seeking information that may strengthen their own safety provisions. Commercial interests are pushed aside in the interests of achieving better safety outcomes through shared learning.”

Thank you to all those organisations and individuals that have shared their observations. The NZMSC look forward to this continuing with our full support. We have a good system in place that will only get better. The sharing of this data is important for the safety of everybody.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

11

climbing feature

The following three articles offer personal perspectives on the theme of ‘climbers / mountaineers and avalanches’.

We hope they generate discussion within the community.

If you have something to say in response to what you read here or on any related topics, please contact the editor

Above: Karl making progress in the Darrans Winter meet 2014. Photo - Jaz Morris (http://jazmorris.smugmug.com/).

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

12

climbing feature - ‘white matter’ // penny goddard Penny Goddard is an avalanche forecaster at the Canadian Avalanche Centre, author of “Avalanche Awareness in the New Zealand Backcountry” and NZMGA ski guide. She is a regular contributor to the Crystal Ball and in this edition looks into avalanche involvements amongst climbers in NZ. In New Zealand, if you’re a climber, the statistics are sobering: 56% of those who died in avalanches since 1900 were climbing . If we include tramping, the number climbs to 64%. People tend to think of avalanches as winter phenomena, mostly affecting skiers and snowboarders, and the images we get from overseas extreme ski/riding movies enhance this perception. But in New Zealand we have a different story to tell.

Less than half (46%) of all fatal avalanche accidents were in winter. 30% of the total were in the summer months of December to February, and 45% of the avalanches which killed climbers were in summer . Around half of the accidents occurred on fine weather days .

How does New Zealand compare to other countries? In Canada, statistics show that only 4% of avalanche fatalities over the last 30 years involved climbers . Studies from France and the United States show that fatalities are most common in the winter months, without the distinctive second spike in

summer which New Zealand’s data clearly reveal.

In those countries, climbers make up a relatively small percentage of the total avalanche victims.

In the years 2007-2010, the average percentage of climbers amongst avalanche victims from 22 European and North American countries was 14%. Slovakia, Slovenia and Poland, on the other hand, shared a high percentage of climbers as avalanche victims .

Concurrent with other countries, most avalanche victims in New Zealand were males in their twenties.

So where are kiwi climbers going wrong? Is it a simple numbers game - just more people climbing than engaging in other types of backcountry recreation? Watching the rush of skiers heading out the back of Treble Cone on a busy day, this is hard to believe. Or is there something markedly different climbers could be doing to improve their chances?

I set about getting some basic information from New Zealand climbers about their trip planning, preparedness for avalanches and general attitude towards avalanche hazard.

Below: Winter climbing 2009. Photo P. Goddard

An online survey sent to New Zealand Alpine Club members yielded an enthusiastic 128 responses. Most people stated that a low or moderate level of avalanche danger was near the top of their priority list when planning a trip (ranking ahead of other considerations such as fun, challenge, convenience and level of difficulty). Most routinely check the Mountain Safety Council’s Backcountry Avalanche Advisory website avalanche.net.nz for conditions information before they go. Almost everyone had some type of avalanche training, including reading books or attending avalanche awareness lectures; however, only 15% had taken a 4-day backcountry avalanche course or higher, which is the recommended minimum for people venturing into uncontrolled, challenging avalanche terrain – i.e. most climbing terrain. But on the whole, you’d have to say that the respondents of my survey were responsible, thinking ahead about avalanches, schooling themselves up a bit and choosing to travel when conditions were suitable.

This type of response seems hugely disparate from a comment made to me recently from a mature climber observing a group of New Zealand’s young cutting edge alpinists: ‘they are not thinking about avalanches at all’. Of course, it’s possible that the people who chose to answer the survey were the keen beans; those already members of the avalanche safety choir.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

13

climbing feature - ‘white matter’ conT’D // penny goddard If I was hoping the survey results to dredge up some clearly reckless attitudes to avalanche hazard which might explain the climbing avalanche statistics, I was disappointed.

However, it’s young males who are most at risk, and it wasn’t young males who answered. While the respondents were predominantly men, the biggest group (33%) was aged 46+, with only 25% of respondents in their twenties.

Perhaps these responsible practices are learned with time and are characteristic of those climbers a little longer in the tooth. Digging a bit deeper, though, I discovered that those who had put things like ‘striving for a specific goal’ or ‘challenge’ ahead of safety considerations on their priority list were a mish-mash of ages and genders, not dominated by those younger male climbers who might be expected to be less cautious. …

A topic sometimes danced around is the place of avalanche rescue gear in New Zealand climbing. Even the most basic of avalanche training will teach the importance of the three essentials of avalanche rescue gear: transceiver, shovel and probe. Much like seatbelts in cars, the statistics around how greatly these devices can improve your chances of survival are hard to argue with. In an ideal world, all climbers would carry these, all the time. However, there are a few things to consider. The survival-improvement statistics did not come from New Zealand, where burial is not always the cause of injury or death in avalanches. Sometimes, traumatic injuries are the problem and transceivers are of little help. And then

there is the climber’s constant dilemma about being light and fast vs. well-equipped and slow. Climbers are always considering the pros and cons of gear, food, and fuel and deciding how little they can get away with carrying. Singlepurpose ‘just-in-case’ items tend to fall down the ranks.

In the survey, many climbers described their tendency to carry some, but not all, of the three rescue items. The most popular mix was to wear transceivers and carry shovels, but no probes, while some others carried shovels and maybe probes, but didn’t wear transceivers. 61% of respondents use all three items all the time while winter climbing, while only 10% use them all the time in summer. One open-eyed individual said he wore a transceiver for body recovery only, while winter climbing in the Darrans.

He is not alone in his perception that a transceiver will not help in a New Zealand climbing avalanche. But is that true?

I took a look through the accounts of climbing accidents since 1900 to try and see what the trends were. In an admittedly subjective process, I considered that a) if there had been a rescue party immediately on site, b) the victims died from asphyxia or hypothermia (rather than trauma) and c) the search was prolonged, that arguably the use of transceivers, shovels and probes would have improved the survival chances of those individuals. I found that in about 15% of New Zealand’s climbing avalanches, this was the case. Not a huge number.

Above: Climber close to Homer Saddle. Photo - Jaz Morris (http://jazmorris.smugmug.com/).

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

14

climbing feature - ‘white matter’ conT’D // penny goddard So what happened in the other ~85% of cases? A terrain trap is defined as any feature which would increase the consequences if you were carried into it by an avalanche.

Unsurprisingly, crevasses, cliffs, waterfalls, rocks and steep faces were common factors in the avalanche reports, causing death by trauma. The other variable was that a number of the avalanches buried the entire climbing party, leaving nobody available for a rescue.

Perhaps these figures are telling a different story: that the travel habits of climbers prevent a rescue from being effective, making the fact that they may not be wearing transceivers a secondary issue. Wearing rescue equipment does no good if everyone in the party gets buried, or if an avalanche carries you into unsurvivable terrain.

Backcountry skiers and snowboarders are more likely than climbers to follow recommended avalanche safety travel practices like going one at a time on avalanche slopes while watching each other, poised and ready to rescue. Climbers tend to rope together or move together, exposing the entire party to avalanche hazard and leaving no room for error.

Climbers also often travel in terrain where a fall would have dire consequences, so that even a small avalanche cannot be tolerated.

Another repeated theme in the accident records was a decision to change route to avoid being in the wind. To seek shelter, parties elected to travel on the lee, windloaded slopes below the ridge, putting the group into prime avalanche country.

In conclusion, then, what is a climber to do? Clearly there’s more to this puzzle than getting everyone using transceivers, shovels and probes (although for the record, this gear is recommended). If you’re climbing, and you intend to travel roped together or move at the same time on or under a slope, or solo, then you need a higher degree of confidence in the snowpack than otherwise. The safe travel practices outlined earlier increase your chances. Confidence can be gained by checking that the posted avalanche danger is low or moderate, avoiding the slopes specified in the avalanche advisory as being most risky, avoiding traveling during or following storms, not travelling on windloaded slopes, staying away from underneath cornices and ice cliffs, and being out of avalanche terrain before the sun heats things up. Back off if you encounter any warning signs, like whumpfing, wind-loading or recent avalanches.

Because of the seriousness of climbers’ exposure, a higher level of avalanche education should become the norm for climbers.

Avalanches are not the random furies of a mountain dragon. Avalanche conditions are usually predictable, and avalanches are usually triggered by the victim or someone in their party. New Zealand is almost out on its own with its relationship between climbers and avalanches. If you are climbing in New Zealand, summer or winter, the stakes are high. It’s worth giving avalanches a second thought.

Above: Penny Goddard and Jim Davidson during NZ Alpine Club Instructor training at Temple Basin.

Photo - Jaz Morris (http://jazmorris.smugmug.com/).

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

15

climbing feature - ‘white matter’ conT’D // penny goddard i 55 people died in avalanches while climbing in NZ between 1900-2013 (from a total of 98). New Zealand Mountain Safety

Council Avalanche Centre, 2013. ii New Zealand Mountain Safety Council Avalanche Centre, 2013. iii 50% of fatal accidents prior to 1999, where time of day was recorded. Irwin, D., MacQueen, W. and Owens, I. 2002,

Avalanche Accidents in Aotearoa New Zealand. iv Storm, I., pers comm., Canadian Avalanche Centre, Revelstoke, BC, Canada, 2013. v Jarry F., and Sivardiere, F. 2000, Characteristics of fatal avalanche accidents in France 1989-1999: Proc Int. Snow Science

Workshop, Big Sky Montana, p. 8-15. vi http://geosurvey.state.co.us/avalanche/US_World_stats/2001-02/US2001-02.html vii IKAR,http://www.ikar-cisa.org/eXtraEngine3/WebObjects/eXtraEngine3.woa/wa/menu?id=298&lang=en viii Department of Conservation, 2013. http://www.doc.govt.nz/parks-and-recreation/plan-and-prepare/safety-in-the- outdoors/be-avalanche-alert/

Above: Nathan Jamieson, Jim Anderson, Rowan Cox, Tanja de Wilde, Will Hulme-Moir, Gemma Wilson and Jaz Morris gaining height towards Ball Pass Photo - Jaz Morris (http://jazmorris.smugmug.com/).

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

16

climbing feature - mountaineers and avalanches // allan uren

Allan Uren is an active winter mountaineer, search and rescue (SAR) leader, and long time ski patroller based in Wanaka. In this article Allan gives his honest perspective of the current state of avalanche risk management amongst the climbing community.

In the history section of an early edition of the Mt Cook guide book it states: “Aggression and blindness to dangerous snow conditions are useful attributes for winter climbing. There were quite a few people with these sort of attributes around in the early seventies.’”

When it comes to avalanches, being a blind raging bull will eventually get you killed. Have mountaineers forty-four years later moved on from this mentality? In 2014 you’d expect for us to be Zen masters with all the accumulated knowledge of avalanches, a deep knowledge of where, how, when avalanches occur and the power they possess to kill us.

The statistics seem to paint a grim picture, whether this is accurate or not doesn’t matter. Any climber getting killed in an avalanche is a tragedy. No one sets out to climb a mountain wanting to get killed, (we should have our eyes open to the possibility), but the game is to come home in one piece. It seems on the face of it, it isn’t the Hollywood monster with a powder cloud that is cleaning up climbers. It’s more common for them to be a small size one or two. If you get caught in a shallow slide on a slope with a good run-out no problem - it’s called an ‘educational pocket’. This same slide above an ice cliff which carries you into a crevasse is usually a death sentence. It’s all about consequence.

That’s what makes climbers so special (apart from the other amazing attributes) we play in nasty terrain with dire consequences. Maybe other backcountry users are getting caught just as much but they’re not dying. Which is cold comfort indeed. Are there improvements to be made and how do we go about achieving it?

Right: Author Al Uren in his element Photo - A. Uren

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

17

mountaineers and avalanches conT’D // allan uren Equipment.

With backcountry skiing carrying a transceiver, shovel, probe and being with people who have the skills to use this gear may save your life. A lot of climbers will not carry it because of the weight. Another justification for not using it is it won’t be of any use if you’re avalanched on the middle section of Cul de Sac, up Cirque Creek in the Darrans. The only thing a transceiver will do there is help rescuers find your body.

But it isn’t always that type of terrain climbers travel in. What about moving around the Fox and Franz Josef neves, the approach to go ice climbing at Wye Creek, or climbing Mt Brewster in winter? All these places have the type of terrain that carrying avalanche safety equipment may help to save your life.

Should all of it be carried? A transceiver without a shovel is useless (apart from the Cul de Sac scenario) and vice versa. You may be able to get away with not having a probe.

Just because you may not ultimately carry this equipment into the hills it doesn’t mean it shouldn’t be considered. It may prompt a conversation on the day about what level of risk you’re prepared to accept. You may discuss the avalanche hazard? Where are the isolated pockets of instability likely to be? Is it going to get worse or better as the day progresses?

Will the approach expose you to large slopes above…? Etc etc. Using the rope as a safety device to safeguard travel in avalanche country should be undertaken with caution. Traversing a snowy ledge with the ability to place rock runners might be appropriate to move through a small section. But running out fifty metres across a broad snow slope with only snowstakes as anchors is likely to create a bigger problem if the slope releases

Above: Al Uren enjoying a day in the Fiordland shade Photo - Jaz Morris (http://jazmorris.smugmug.com/).

How do you tame the Bull? The beast that drives us to push the boundaries in the mountains. There’s nothing wrong with going into the mountains and risking your life, that is one of the magical aspects and freedoms of mountaineering. Sometimes you have to commit, ‘slap your balls on the table’ as the saying goes. But making sound judgement calls based on good knowledge is better than ploughing onwards hoping the slope won’t fail. Tempering ego and ambition when it comes to avalanches is difficult, especially when you’re looking up at the glistening heights. It’s possibly one of the hardest things to do - to turn around when the slope goes whoomph and doesn’t release. At this moment no one can tell you what to do.

Communication between party members is possibly the most important thing you can do. As you approach a climb, even in the gnarliest of places there are decision points. Discuss whether to continue, “what is the best route to take?”, “is everyone happy?” It’s amazing how many avalanche accidents have happened where no one has voiced their concerns.

Summer avalanches do happen but they are potentially easier to forecast. We all know that starting early to avoid a mushy snow slope in the afternoon is good for health and safety. If through no fault of your own, you end up having to descend a mountain in the full sun, maybe wait until it refreezes. Once again this is where good mountaineering skills come in.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

18

mountaineers and avalanches conT’D // allan uren Background image: Alexis Belton approaching the south face of Glengyle Peak (2283m) in the West Matukituki valley, Mt Aspiring National Park Photo - Jaz Morris (http://jazmorris.smugmug.com/).

Avalanche knowledge is a life long pursuit. It doesn’t matter how you get it but it can’t be gained just through doing courses.

Read books, trawl the Internet, and talk to crusty old climbers, ski patrollers. It can be difficult to gain enough experience and knowledge if you don’t go into the mountains a lot. Ski touring is a good way of gaining snow sense because you have time to observe the subtleties of the snow surface; you may be more likely to dig into the snow. And not just those little test column thingies with your hand, they only give you surface conditions.

When in the hills, even the avalanche guru will have trouble making an accurate assessment of snow stability, as it’s difficult to gather hard data to make an accurate forecast. This is when being a mountaineer and using good travel techniques is important. Not overloading a slope, going around the small pillow, travelling on ridges not lee slopes, camp in smart places, choosing to remain in the hut.

So are New Zealand mountaineers better at reading snow than they were in the 1970s?

No, they aren’t.

Tools, techniques, food, clothing, mental and physical training has surged ahead. But avalanche knowledge amongst the majority hasn’t kept up.

And that needs to change.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

19

climbing feature -personal reflection

// geoff gabites

Ageing mountaineer Geoff Gabites has been around the outdoors for a long time. From setting up early outdoor retail store The Wilderness Shop in Dunedin and the outdoors Wilderness label that became Macpac Wilderness in the 1980s, Geoff climbed in the Darrens and Mt Cook regions as well as overseas with expeditions to Nepal, China, India, Pakistan and Peru. A Past President of the NZ Alpine Club, he remains an active member of the club, chairing the Executive Committee and participating with the Club Committee Meetings. Geoff now operates Adventure South, a leading cycle tour and trekking company.

Viewed from below, or from the target zone, an ice avalanche is a terrifying thing. My personal experience on the west face of Ama Dablam many years ago, still comes back to haunt me. Conversely, the two near misses I have had at Mount Cook, are much more fringe, sending a shudder when thinking about what might have been, instead of the physical and emotional scars of what was.

Our Mount Cook experience was brought about firstly because we were dumb. Not ignorant of risks of avalanches in isolation, but definitely the ramifications of embarking on a winter trip on the South Ridge of Mt Green that in its entirety would expose us to avalanche danger should the weather turn bad. Which of course it did – but not unexpectedly so!

Ken & I made the decision to fly into the mid Tasman Glacier landing strip in June and from there gain the base of the South Ridge of Green from under Climbers Col via a gulley on the far left of a bergshrund line that grew to form a huge ice cliff on the far right, under our proposed climb. To access our starting point we had to access a small avalanche gully and then traverse a snow slope to the base of the ridge.

“...common sense and common practice are seldom in tandem in the face of ambition.”

Above: Large slab avalanche on the Mannering Glacier August 4 2014. Photo - Trev Streat

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

20

climbing feature -personal reflection conT’D

// geoff gabites

Common sense in the face of the weather should have prevailed, but common sense and common practice are seldom in tandem in the face of ambition. The confusing weather signs waited until our credit card had been swiped and we were seated in the plane before making themselves obvious. We waded through winter snow to the gully and then across the slope and by evening had dug a platform inside a sheltering crevasse.

When the storm rolled in, it did so quietly but efficiently. I awoke buried in spindrift which had flowed down into our slot, and the sky outside was heavy with cloud and a gentle snowfall. Clearly the climb was over – but firstly we needed to get back the way we came.

Unroped, I started across the slope, but took no more than 2 steps before the slope exploded beneath my feet, sliding away and pouring over the icecliff below us. Another attempt, this time roped, had Ken being swept off his feet before we both regrouped, chastened and scared back into our crevasse.

The way home became a crawl across the laden slope following the line of the crevasse willing the snow pack to stay in place.

Then we descended the avalanche gully on the far left staying away as much as we could to avoid the sloughs regularly dropping from the slopes above. Inevitably we couldn’t miss them all and we were swept from the slopes and deposited over the crevasse below on the downhill side.

A full day later we finally waded down the Tasman and up the moraine wall to escape the hell of the past three days.

Ama Dablam conversely was very different. The West Face was unclimbed, - probably because of the obvious risk formed by the three ice cliffs that drained the central gullies. Peter had spent 10 days at our Base Camp pre monsoon watching and observed no activity. We spend another 7-8 days post monsoon at Base Camp watching intently and fixing ropes through the bottom rock band, again observing no ice falls in the central gully. Finally, decisions made, we set out.

Altitude slows things down but nightfall had us about halfway. Cutting out narrow sleeping ledges was difficult and the following morning showed how spectacular our site was. We were slow to start as we crept across gullies and eventually through the second rock band to emerge onto the snow slopes above. The traverse across to the top of the left hand ice cliff was perhaps another hour away, putting us out of future firing zones and giving us a risk ‘free’ route from there to the summit.

Accidents often happen on the last day, the last abseil, or within 15km from home.

Ama Dablam is named for the necklace formed by the ice cliff below the summit slopes. This ice cliff, completely quiet until now, chose this time to disgorge and changed our lives forever.

From below, an ice avalanche looks like white blocks filling the sky. Fear took over and we crouched, trying to make ourselves invisible behind our helmets, as if these fragile fibreglass shells can do more than divert pebbles and ice chips. Ice falling in large blocks from above is unforgiving and undiscriminating. Life is so fragile and yet the body can withstand so much. In this case, survival for 3 of our party of 4 was amazing.

Three days later we escaped from the bowling alley that is the West Face. No further ice fall occurred, and with the help of very brave and committed international climbers below, we were assisted back to Base Camp and the recovery that followed for all but one.

Several decades on, the experience of these two trips has often had me asking myself what lessons I had learned – and what would I have changed. Our close call on Mt Green was caused by blind commitment to going climbing – in the face of a weather forecast that was clearly pointing to an adverse event. This was a dumb decision on our behalf and we were plain lucky to survive.

Ama Dablam was much more calculated and reasoned. It was about weighing up the risk and the likelihood of an ice fall. The empirical evidence indicated a potentially safe climb, but the risk is always there, unchanging and constant. We accepted the risk.

Some climbing routes in the Darrens have a high potential snow avalanche risk and hence a knowledge of snow pack and past weather events needs to play a major role in the decision making.

Background image: Low angle slab releases on the Leckie Glacier, Murchison Valley, Aoraki/ Mt Cook National Park. August 4 2014.

Photo - Trev Streat

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

21

climbing feature -personal reflection conT’D

// geoff gabites

I was recently invited to talk at the Remarkables Ice Climbing Festival in Queenstown, and was pleasantly encouraged by the discussions I heard. I was struck by how the climbers of today appear more aware to seek a better understanding of avalanche mechanics and their triggers. Whether this ‘festival’ environment was representative of what happens when climbers are managing risks out on their own I can’t say.

Gatherings such as the Remarkables Ice Climbing Festival are potentially a major conduit to foster more sharing of this type of information. Many at the festival had fast tracked their learning by having already attending dedicated avalanche courses.

NZ statistics show that climbers feature proportionally high in avalanche fatalities, so establishing the norm of developing a strong technical knowledge of ‘Avalanche Awareness’ will be crucial for the future of climbers in this country.

Having climbed routes on the South Face of Barrier and in the MacPherson cirque I recognise a potential bad outcome.

Avalanche danger can be minimised by paying attention and using your knowledge and experience.

Potential ice falls from ice cliffs don’t provide the same opportunity to evaluate the risk. Sooner or later you get yourself in a spot where you have to ask yourself “is this a risk we are prepared to take?”

Shortly followed by ”do you feel lucky?

....... well do ya?”

Above: Rasterised composite image - Editor

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

22

research - Airbags effectiveness, an updated study // pascal haegeli

Pascal Haegeli is a Canadian avalanche researcher and safety consultant based out of Vancouver, Canada. His interdisciplinary research aims to allow backcountry travellers can make better informed choices when heading into avalanche terrain. Pascal is also an adjunct professor at the School of Resource and Environmental Management at Simon Fraser University.

Pascal Haegeli, Markus Falk, Emily Procter, Benjamin Zweifel, Frédéric Jarry, Spencer Logan, Kalle Kronholm, Marek Biskupic Hermann Brugger Over the last five years, the use of avalanche airbags has increased dramatically, both among professional guides and amateur recreationists. While there were only a couple different airbag types on the market ten years ago, backcountry enthusiasts can now choose from a wide range of models produced by at least four different manufacturers. In addition, a few new manufacturers are pushing into the growing market with their own innovative designs.

Avalanche airbags have a tremendous potential to save lives, since they are the only avalanche safety device that can directly prevent or reduce the severity of avalanche burial—the root cause of the majority of avalanche deaths. As a consequence, some avalanche warning centers now recommend airbags as a useful complement to the traditional avalanche safety tool kit of transceiver, probe and shovel. Whereas the underlying mechanism for the effect of avalanche airbagsi has been validated conclusively using mathematical models and field tests, the precise effect of airbags on avalanche mortality is still being debated. While manufactures like to present airbags as the ultimate avalanche safety device (e.g., “97% survival”, “8x safer!”ii), prominent avalanche educators try to warn against the ‘silver bullet’ marketing by highlighting that the number of lives saved per 100 fatalities might only be in the single digits.iii Since both sides claim their analyses are based on solid data and rigorous statistics, it is difficult for the layperson to determine what’s right and what’s wrong. However, an accurate and easily understandable presentation of the true effect of airbags on avalanche mortality is important. According to a study by Christie (2012) from Backcountry Access, survival statistics are the most important reason for airbag purchases among their customers.

A number of independent statistical evaluations have assessed the effectiveness of airbags, the most prominent of them is the analysis by Brugger et al. (2007). However, due to the small number of incident records involving airbags available at the time, the analysis has limitations and the results should be interpreted cautiously. More recently, Shefftz (2012) compared the available ABS airbag involvement data to various avalanche accident datasets to estimate the range of impact airbags might have on avalanche survival. However, this type of comparison also has challenges that limit the resulting conclusions.

The goal of this article is to provide an up-to-date perspective on the effectiveness of airbags based on a detailed study we recently published in the journal Resuscitation (Haegeli et al., 2014). In addition to simply presenting the results of the study, we also want to take this opportunity to describe the challenges that evaluations of avalanche safety equipment face in detail. We hope that this information will help backcountry recreationists to assess marketing claims more critically and make better informed choices when deciding whether to add an airbag to your avalanche safety kit or not.

Mortality, mortality difference and mortality ratio Whenever you read statistics—airbags or otherwise—you should immediately ask yourself the following questions: • What is the question they are trying to answer?

• Where is the dataset coming from?

• What kind of assumptions were made during the analysis?

Without a clear understanding of this context, the presentation of statistical figures is meaningless, even if numbers might actually be technically correct.

The first step of examining the effectiveness of any safety device is therefore to specify the question you want to answer. We think that the most interesting questions for the evaluation of avalanche airbags are: 1) 2)

How does the use of an avalanche airbag affect my chance of getting killed in a serious avalanche involvement?

How many avalanche fatalities could be prevented with the widespread use of avalanche airbags?

The statistical measures used to answer the two questions are the mortality difference for the first question and the mortality ratio for the second question. These two measures are closely related, but they offer different perspectives on the effectiveness of airbags and it is important to clearly understand their differences.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

23

research - Airbags effectiveness, an updated study conT’D // pascal haegeli We are using the results of the study by Brugger et al. (2007) to explain the meaning of these two statistical measures in detail. The dataset used by Brugger and colleagues consisted of 1504 avalanche involvements occurring in open terrain in Switzerland and Austria between 1990 and 2005. Thirty-five of the avalanche victims included in this dataset were equipped with airbags during their involvement. Out of 100 victims involved in avalanches without airbags (control group), 81 survived because they did not sustain any fatal injuries and did not get buried or were found and extricated in time (Table 1). This is equivalent to a mortality rate of 19%. Out of 100 avalanche victims equipped with airbags (treatment group) 97 survived, which corresponds to a mortality of 3%.

Table 1: Dataset of Brugger et al. (2007).

Survived Killed Total Without an airbag (control) 1191 (81%) 278 (19%) 1469 With an airbag (treatment) 34 (97%) 1 (3%) 35 Total 1225 279 1504 Based on the data presented in Table 1, Brugger et al. (2007) showed that that the use of avalanche airbags results in a significant reduction of the mortality by 16 percentage points from 19% to 3% (Fig. 1, left axis). This is the so-called mortality difference. The mortality ratio scales or normalizes the mortality of victims with airbags with the original mortality of victims without airbags (mortality of the treatment group divided by the mortality of the control group; Fig. 1, right axis). In the study of Brugger et al. (2007), the mortality ratio is 15%, which means that out of 100 avalanche victims killed without airbags, 15 would still die even if all were equipped with avalanche airbags. In other words, 85 of 100 fatalities could have been prevented with the use of airbags.

Fig. 1: Mortality difference and mortality ratio illustrated with the results of Brugger et al. (2007) Only relevant cases To date, the vast majority of analyses on the effectiveness of airbags were based on an airbag involvement dataset that was collected collaboratively by the ABS airbag manufacturer and the WSL Institute for Snow and Avalanche Research SLF. This dataset is almost entirely European and it includes a wide spectrum of incidents ranging from large avalanche with multiple burials to small avalanches where single victims managed to avoid being buried. While all of these cases provide valuable information on airbag performance, not all of them are suited for a statistical analysis of the effect of airbags on mortality. A detailed description of the criteria used to put together the analysis dataset (Were all known airbag incidents included in the analysis or did it only focus on a specific subset?) is of utmost importance when interpreting statistical results.

One of the goals of our study was to collect a larger and geographically more comprehensive dataset that is well suited for truthfully estimating the effectiveness of airbags. Existing records of well-documented avalanche accidents involving at least one airbag user were collected from data sources in Canada (Canadian Avalanche Association), France (National Association for Snow and Avalanche Studies), Slovakia (Avalanche Prevention Center), Norway (Norwegian Geotechnical Institute, Norwegian Red Cross), Switzerland (WSL Institute for Snow and Avalanche Research SLF) and the United States (Colorado Avalanche Information Center). Since airbags are designed to prevent or reduce the severity of avalanche burial, we focused on avalanche involvements with the potential for full burial. This was accomplished by including only incidents with avalanches of a destructive size 2 or larger according the Canadian or American avalanche size classification and including only victims who were seriously involved in the avalanche. This means that they were either seriously involved in the flow of the avalanche or hit by the avalanche from above then partially or completely buried. Victims who were only slightly moved at the edge of the avalanche, managed to remain standing during entire involvement or even ride out of the avalanche were excluded from the dataset as airbags are unable to affect the outcomes of these types of involvements. The resulting dataset consists of 245

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

24

research - Airbags effectiveness, an updated study conT’D // pascal haegeli incidents with a total of 424 seriously involved individuals. Two hundred and forty-six (58%) of the included victims had an inflated airbag, 61 (14%) had an airbag that was not inflated during the involvement, and 117 (28%) were not equipped with airbags.

Unbiased control group The accurate assessment of airbag effectiveness requires a reliable control group of victims without airbags. The challenge is that many avalanche incidents with good outcomes (i.e., no fatalities or major injuries) simply never get reported. This prevents us from calculating a reliable base mortality for avalanche involvements. Since both airbag manufacturers and avalanche safety researchers are actively hunting for the information on avalanche accidents involving airbags, it is likely that the reporting rate of non-fatal avalanche accidents with airbags is considerably higher. This difference in reporting rates can unintentionally skew the results of statistical analyses on the effectiveness of airbags.

To obtain a control group that is as comparable as possible to our airbag cases, we limited our analysis to only include accidents that involved both users and non-users of avalanche airbags. This allowed us to extract both the treatment group and the control group from the same accidents, therefore avoiding any reporting biases. However, the price for this unbiased control group is a considerably smaller dataset that only includes 35% (106 of 307) of the available records on seriously involved individuals with airbags and is skewed towards larger avalanches with multiple involvements. Remember this when interpreting the final results.

Controlling for other factors affecting mortality: adjusted mortality rates Airbags are clearly not the only factor affecting your chance of surviving an avalanche involvement. The size of the avalanche, your location when the avalanche releases, the character of the runout zone, whether you get injured and whether you wear an avalanche transceiver all have the potential to affect the outcome of your involvement. Because all of these factors work together, a simple cross table like the one shown in Table 1 is unable to correctly separate the effect of airbags from the other contributing factors.

To account for the other contributing factors in our analysis, we collected information on a large number of parameters describing the characteristics of the incident, the avalanche and the victims. We then examined the influence of all these factors on mortality simultaneously using a statistical technique called binomial logistic regression analysis. This method allows us to properly identify and separate effects of the individual contributing factors. The results of this analysis were then converted into adjusted mortality rates, which are interpreted in the same manner as mortality rates calculated from cross tables. The interested reader is referred to our paper in Resuscitation to get the full list of parameters included in the analysis and read the full details on the logistic regression analysis.

What did we discover?

The results of our analysis support the finding that airbags significantly reduce the mortality in serious avalanche involvements, but the effect is lower than previously reported. The analysis revealed that airbags affect mortality only indirectly through their influence on victims’ grade of burial.iv Other factors affecting grade of burial are avalanche size (the larger the avalanche the higher the likelihood of a critical burial) and whether the victims sustained a major traumatic injury during the involvement (higher likelihood of critical burial with major injury).v The adjusted risk of critical burial is 47.0% for victims without airbags or with non-inflated airbags, and 20.1% for users with inflated airbags.

Mortality is subsequently determined by grade of burial, avalanche size and major traumatic injuries. The adjusted mortality is 43.8% for critically buried victims and 2.9% for non-critically buried victims. The adjusted mortality with and without an inflated airbag can now be calculated by multiplying the adjusted risk of critical burial with respect to airbag use and the adjusted mortality with respect to critical burial as illustrated in Fig. 2.

Fig. 2: Calculation of adjusted mortality with respect to the use of inflated airbags.

Adjusted risk of critical burial with respect to airbag use Adjusted mortality with respect to critical burial

Adjusted mortality with respect to airbag use

(treatment group)

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

(control group)

25

research - Airbags effectiveness, an updated study conT’D // pascal haegeli While the mortality without inflated airbags is 22.2%, the mortality with inflated airbags is 11.1%. This results in an adjusted mortality difference of 11 percentage points (95% confidence interval is -4 to -18 percentage points) and an adjusted mortality ratio is 0.5 (95% confidence interval is 0.3 to 0.7).

This means that out of 100 victims without airbags seriously involved in avalanches similar to the ones included in the analysis dataset 22 are killed and 78 survive because they did not sustain any lethal injuries, did not get buried during their involvement, or were found and extricated in time. Out of 100 victims equipped with inflated airbags, only 11 would have been killed.

In other words, an additional 11 victims would have survived due to the airbags, which means that half of all fatalities could have been prevented. These effects are significant, but they are not as good as previously reported (-11 percentage points versus -16 percentage points in Brugger et al., 2007). Furthermore, the mortality of airbag users is significantly higher than previously reported (11% versus 3% in Brugger et al., 2007). While this difference is partially due to the fact that our analysis focused on larger avalanche accidents with multiple involvements, it clearly highlights that airbags do not guarantee survival under all circumstances. Even if all victims in the present dataset were equipped with inflated airbags, one of every nine victims would have died.

What about non-inflations?

So far we have examined only the benefit of inflated airbags. In other words, the 11 percentage point decrease in mortality represents the best case scenario when airbags are properly deployed and inflate as designed. However, past studies have repeatedly highlighted non-inflations as a serious problem for the performance of airbags. To examine non-inflations, we used all available records of airbag users including ones from accidents that only involved single users. The resulting dataset consisted of 307 records from 245 accidents. The overall non-inflation rate within this sample was 20% (61 of 307), which is very close to the rate reported by Brugger et al. (2007). This non-inflation rate reduces the 11 percentage point decrease in mortality from inflated airbags to roughly 9 percentage points (i.e., 80% of 11 percentage points). This clearly highlights that non-inflations still pose a considerable threat to the airbag performance.

What are the causes for these non-inflations? Information on suspected causes was available for 52 cases: • 60% deployment failures by users • 12% maintenance errors (e.g., canister not attached properly) • 17% device failures (i.e., performance issues that resulted in design and/or production revisions) • 12% destruction of airbag during involvements Relative to the total number of users, the rate of airbags destroyed in involvements was 2% (6 of 307) and the rate of device failures was 3% (9 of 307).

To better understand the reasons causing users not to deploy their airbags, we examined the dataset for relationships between non-deployment and any relevant victim or involvement characteristics. Since we did not detect a significant relationship between deployment rates and avalanche size, non-deployments do not seem to be the result of more violent involvements. However, we found that the non-deployment rate is significantly lower among avalanche professionals (e.g., guides, ski patrollers, avalanche technicians) than recreationists (5% versus 14% respectively). This suggests that familiarity with airbags and their deployment procedures may considerably improve the effectiveness of these devices.

How about risk compensation?

Risk compensation is a common concern when weighing the pros and cons of avalanche airbags. Are users going to feel less vulnerable when wearing an airbag and therefore expose themselves to a higher level of avalanche hazard? While there is no empirical evidence to date on risk compensation behaviour with respect to airbag use, it is a well-studied phenomenon in other areas. Hedlund (2000) offers a summary of existing evidence on risk compensation with respect to road safety initiatives. He states that while risk compensation does occur—even though not consistently—it generally does not eliminate the safety gains from the programs, but only reduces the size of the expected effect. It would be extremely difficult to collect the necessary data to properly quantify the effect of risk compensation on the effectiveness of airbags. However, Hedlund (2000) provides an interesting personal list of four characteristics of safety equipment or initiatives that make risk compensation more likely: 1) 2) 3) 4)

Is the piece of safety equipment obvious? Do I even know it is there?

Does the piece of safety equipment affect me negatively, physically and/or mentally?

Does the effect of the piece of safety equipment directly relate to the motivation and objective of my activity?

How much control do I have over my actions? Can I even change my actions if I want to?

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

26

research - Airbags effectiveness, an updated study conT’D // pascal haegeli Airbags seems to generally score highly on all of these characteristics: 1) 2) 3)

4)

It is difficult to forget the fact that you are carrying an airbag as they require frequent attention.

Airbags are expensive and heavy, and handling them during a trip can have its challenges.

If your primary reason for going into the backcountry is to ski challenging terrain, the benefits of airbags are perfectly aligned with your objective; if you are simply going into the backcountry to enjoy nature and calm, the effect of airbags is much less connected to your goals.

While amateur recreationists have complete freedom and control over their actions, avalanche professionals are likely more restricted due to company procedures and policies or professional best practices.

Based on this list of characteristics, it can be assumed that that risk compensation behaviour is likely among airbag users, particularly among recreationists who are interested in pushing their physical and athletic limits.

While our study does not provide any information regarding the presence of risk compensation behaviour with airbags, the results of our analysis offer some insight about the possible consequences of risk compensation behaviour. The parameter estimates from the binomial logistic regression analysis on critical burial indicate that the risk reduction gained from the use of an airbag is roughly equivalent to the risk increase from being involved in an avalanche of one size class larger. This means that personal safety benefits from airbags are quickly nullified if individuals use them to justify increased exposure to terrain where larger avalanches are likely.

Limitations Clearly stating the limitations of an analysis is important when presenting statistical results. In our analysis of the effectiveness, the sample of airbag user records was substantially smaller than the complete dataset (201 records were excluded out of 307 total) to ensure an unbiased control group. The resulting dataset was therefore skewed towards large avalanches with multiple involvements. Furthermore, the dataset had a lower percentage of avalanche professionals and a higher percentage of victims located in the track or runout when the avalanche was triggered. Remember these limitations when interpreting the mortality statistics presented in this article. While the mortality among airbag users in the excluded records (i.e., smaller avalanches, single involvements) is smaller than in the analysis dataset, it is unclear how the effect of airbags shown in the present analysis transfers and contributes in relation to the reduced mortality from smaller avalanche and other differences.

Take home messages What are the most important take home messages from our study?

•

Airbags are a valuable safety device, but their impact on mortality is lower than previously reported and survival is not guaranteed.

•

For individuals seriously involved in avalanches of size 2 or larger, the use of an inflated airbag reduces the risk of dying from 22% to 11% (Fig. 3). This means that inflated airbags will save about half of the victims who would have otherwise died.

•

Non-inflations remain the most considerable limitation to the effectiveness of airbags. The observed overall non-inflation rate from all causes is 20%.

•

If non-inflations are taken into account, airbags reduce the risk of dying from 22% to 13% (Fig. 3) and the proportion of saved victims is only 41%.

•

Sixty percent of all non-inflations are due to deployment failures by the user. Familiarity with deployment procedures and proper maintenance are paramount for ensuring that airbags work properly.

•

Personal safety benefits from airbags are quickly nullified if users use them to justify increased exposure to terrain where larger avalanches are possible.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

27

research - Airbags effectiveness, an updated study conT’D // pascal haegeli Where to go next?

While our results show that airbags can reduce mortality in serious involvements in general, the analysis does not provide any insight about the benefit of airbags under different circumstances. For example, it would be useful to estimate and compare the effectiveness of airbags in avalanches with smooth runout zones versus avalanches with terrain traps. Another interesting question would be to examine the effectiveness of airbags as a function of the location of the victim when the avalanche was triggered (start zone, track, runout). However, collecting reliable avalanche accident data is challenging and records are often incomplete. We would like to encourage national avalanche safety agencies, international search and rescue associations, airbag manufacturers and researchers to work together to develop standardized data collection protocols to facilitate future studies. In addition, we would like to encourage recreationists to diligently report Fig. 3: Effect of airbags on the mortality of victims all types of avalanche involvements to the local avalanche seriously involved in avalanches. warning services. The resulting richer datasets will facilitate more detailed studies that will further improve our understanding of the benefits and limitations of airbags and other avalanche safety devices, avoid misleading statements on the impact of these devices, and help users to make better informed choices.

Acknowledgements We thank the many individuals who contributed to the collection of avalanche accident information that made this research possible. We would also like to acknowledge Bruce Tremper and Jonathan Shefftz, who provided valuable comments on an earlier draft of this paper.

References Brugger, H., H.-J. Etter, B. Zweifel, P. Mair, M. Hohlrieder, J. Ellerton, F. Elsensohn, J. Boyd, G. Sumann, and M. Falk, 2007:

The impact of avalanche rescue devices on survival. Resuscitation, 75, 476–483.

Christie, S., 2012: Avalanche Airbag Survey: A U.S. Perspective. Paper presented at 2012 International Snow Science Work

shop in Anchorage, AK, 361–362 [available at http://arc.lib.montana.edu/snow-science/item.php?id=1700].

Haegeli, P., M. Falk, E. Procter, B. Zweifel, F. Jarry, S. Logan, K. Kronholm, M. Biskupic, and H. Brugger, 2014: The effective

ness of avalanche airbags. Resuscitation, 85,1197-1203..

Hedlund, J., 2000: Risky business: safety regulations, risk compensation, and individual behavior. Injury Prevention, 6, 82–90.

Shefftz, J. S., 2012: Enhanced avalanche survival from airbag packs: Why can we learn from the data? The Avalanche Re

view,30, 8–9.

i

Inverse segregation, also known as the “Brazil nut effect”, naturally sorts particles within an avalanche according to size with larger particles being moved towards the surface of the avalanche. Inflated avalanche airbags make avalanche victims, already large particles, even larger particles within the avalanche, which increases their chances to end up on top of the debris before the avalanche comes to a stop. Buoyancy effects, which are used by floatation devices, do not play a role in avalanche airbags. ii https://www.abs-airbag.com/us/abs-survival-principles.html. iii Dale Atkins in the 2011 November issue of Powder Magazine (http://www.powder.com/stories/know-bounda ries-5/). iv Grade of burial was defined as either critically buried (i.e., head of the victim under the snow and breathing impaired) or non-critically buried (i.e., unobstructed airways). v Traumatic injuries are considered major if the injured requires hospitalization.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

28

research - Avalanches, a positive effect // heather purdie - Dept of geography, university of canterbury

The role of avalanche on snow accumulation on small alpine glaciers Heather Purdie1 and Wolfgang Rack2 1Department of Geography and 2Gateway Antarctica, University of Canterbury (UC) Research on snow avalanche typically focuses on the hazard, considering things like the strength and variability of the snowpack, and relationships between weather patterns, snow accumulation, and snowpack structure. However, our current research is a bit different, we are thinking about avalanches in a positive way….

The New Zealand Southern Alps have over 3100 glaciers (Chinn, 2001). Many of these glaciers are small ‘cirque’ type glaciers, which often span only 200-400 m in elevation. This small elevation range means that these glaciers are potentially very vulnerable to climate warming. A 1°C increase in temperature can elevate the snowline of a glacier by around 150 m, thereby increasing the area of the glacier that is subject to net ablation or melting. Glaciers form in locations where more snow and ice accumulates each year than is lost by summer melting; and the altitude where snow gains equal snow and ice loss is the permanent snowline, often referred to as the annual equilibrium line altitude (ELA). Scientists are very interested in measuring the mass balance of glaciers (gains – losses) as this provides information about glacier health, and changes in climate manifest in glacier mass balance.

Aside from their small size, cirque glaciers tend to be surrounded by steep headwalls and it is not uncommon for snow to avalanche down onto the glacier from the surrounding steep terrain. However, just how much snow these small New Zealand glaciers receive from avalanching is still unknown. The importance of avalanche input to glacier mass balance is well recognised, especially in the Himalaya (Hewitt, 2011).

But the percentage contribution that avalanche can make to overall snow accumulation on a glaciers can vary from around 10-60%; influenced by factors like glacier morphology and location (Lossev, 1967).

Therefore we are investigating how important avalanche is to overall mass balance on small cirque glaciers in the Southern Alps.

Above: Dr Wolfgang Rack with UC student Matthew Linton, undertaking a GPR survey on the Rolleston Glacier in November 2013 – photo H. Purdie

Left: Heather’s husband and NZMGA Hard ice and Trekking guide Jason Watson testing his shovel to verify GPR results - photo H. Purdie

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

29

research - Avalanches, a positive effect conT’D // heather purdie - Dept of geography, university of canterbury

Above: Dr Wolfgang Rack with UC student Matthew Linton, undertaking a GPR survey on the Rolleston Glacier in November 2013 – photo H. Purdie

To test our hypothesis, we are undertaking research on the Rolleston Glacier, perched on the eastern flanks of Mt Philistine in Arthurs Pass National Park. A ground penetrating radar (GPR) was used to survey snow depth at the end of winter. In a GPR survey, the radar signal is reflected from changes in the snowpack, for example an icy layer, and the two-way-travel time of the reflected signal is converted to depth using measurement of snow density. The previous summer’s surface provides a strong reflection, but we also dig snow-pits and take probe measurements to ensure we interpret the radar-gram correctly. In 2013 the average depth of the winter snowpack on Rolleston Glacier was 5.8 m, with an average snow density of 540 kg m-3.

However, in the regions affected by avalanches cascading off Mt Philistine the snow depth was 10-12 m. By the end-of-winter approximately 16% of the total glacier area was observed to contain avalanched snow.

Combining our snow depth data with a simple snow accumulation model, which utilises precipitation and temperature data from the nearby NIWA high-elevation weather station, we estimate that avalanched snow may be contributing around 25% of annual snow accumulation on Rolleston Glacier. The next steps are to compare our GPR data to a more advance accumulation model, one that includes a gravitational transport component, and to test the sensitivity of the Rolleston glacier to future climate change.

Our research is not only relevant to glacier mass balance studies. Improved understanding of current snow accumulation processes and patterns is crucial if we are to better predict future changes to the ski industry and to our favourite backcountry routes.

Chinn, T. J. (2001) Distribution of the glacial water resources of New Zealand. Journal of Hydrology (NZ) 40, 139-187.

Hewitt, K. (2011) Glacier change, concentration, and elevation effects in the Karakoram Himalaya, Upper Indus Basin. Mountain Research and Development 31, 188-200.

Lossev, K. S. (1967) The role of avalanches in mass budget of glaciers. Physics of Snow and Ice : proceedings, International Conference on Low Temperature Science. I. Conference on Physics of Snow and Ice, II. Conference on Cryobiology, August, 1419, 1966, Sapporo, Japan, 385-388.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

30

research - Brewster glacier climatology // nicolas cullen - Dept of geography, university of otago

Establishing a long term climatology for Brewster Glacier, Haast Pass Nicolas J. Cullen - Department of Geography, University of Otago, Dunedin, New Zealand The Brewster Glacier, located just west of the main divide near Haast Pass, is popular with alpine climbers and ski touring parties because of its quick access from the road and relatively new and comfortable hut. However, the glacier holds importance beyond its recreational value, being the site of consistent and at times intensive glaciological and meteorological monitoring.

The mass balance of Brewster Glacier (an assessment of the total volume of the glacier) has been conducted by the University of Otago and Victoria University, with the financial support of NIWA, for just over a decade making it the longest in situ record of a glacier’s mass ever obtained in the Southern Alps.

Figure 1: The automatic weather station near the terminus of Brewster Glacier. Mt. Brewster can be seen in the background.

To establish the atmospheric controls on glacier behaviour an automatic weather station was installed next to the lake near the terminus of Brewster Glacier at the start of the mass balance programme (Figure 1). The early part of the climate record from the weather station is compromised to some extent due to instrument failure but after replacing and upgrading all the instruments in the early part of winter in 2010 it has provided a continuous and high quality meteorological data set. During a two year period an additional weather station was maintained on the lower part of Brewster Glacier (2010-2012), which has been used to characterize the near surface atmospheric processes controlling the inputs (snow) and outputs (ablation) over the glacier (e.g. Conway and Cullen, 2013; Conway et al., 2014).

Importantly, the meteorological data obtained on Brewster Glacier has allowed us to assess more broadly some of the uncertainties associated with modelling the surface energy and mass balance of glaciers in the Southern Alps, while also giving us the opportunity to improve our understanding of the local climate. An assessment of the the seasonal variability in air temperature and precipitation has shown how sensitive a glacier such as Brewster can be to small perturbations in climate.

For example, Figure 2 shows the air temperature range at which precipitation falls on the lower part of Brewster Glacier (at approximately 1760 m above sea level). It is striking how much of the annual precipitation, which is approximately 5000 mm water equivalent at this location, falls very close to the rain/snow threshold. Small changes in air temperature will therefore have a strong influence on the amount of precipitation that falls as rain or snow in the future.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

31

research - Brewster glacier climatology conT’D // nicolas cullen - Dept of geography, university of otago

Figure 2: The fraction of total precipitation versus air temperature as recorded on the glacier over a two year period (2010-12) at an elevation of 1760 m above sea level. The key feature is that the majority of precipitation at this elevation falls very close to the rain/snow threshold.

What sets the present weather station at the terminus of Brewster Glacier apart from other high altitude weather stations in the Southern Alps is the high quality, research grade radiation instrument, which has enabled the cloud effects on incoming shortwave, longwave and net radiation to be carefully described (Conway et al., 2014). The radiation measurements have allowed a cloud climatology for the region near Brewster Glacier to be established, which has been closely compared to in situ observations of precipitation (both rain and snow). We believe this research could be of interest to those in the ski industry as the impacts of weather systems on cloud cover and snowfall events have been carefully assessed. In particular, the influence of airmass source on air temperature and precipitation over time has been carefully scrutinized. As snow forecasters working in the industry will appreciate, the freezing level associated with an approaching air mass laden with moisture can be critical in determining whether a ski field or high elevation area receives precipitation as rain or snow.

Improving our ability to provide reliable avalanche forecasts is critical on having access to real time, high quality atmospheric observations from mountain locations. While the automatic weather station at Brewster Glacier has been used primarily for research up until this time I am interested in hearing from the broader community whether there is a need in making the data available online in real time, which can be achieved if there is strong desire. If you do have an interest in seeing data streamed online please send me an email, which will help me build a case to source funding to implement this upgrade for the broader community (nicolas.cullen@otago.ac.nz).

References Conway, J., and Cullen, N.J. 2013: Constraining turbulent heat flux parameterisation over a temperate maritime glacier in New Zealand. Ann. Glaciol., 54, 41-51, doi: 10.3189/2013AoG63A604.

Conway, J., Cullen, N.J., Spronken-Smith, R.A., and Fitzsimons, S.J. 2014: All-sky radiation over a glacier surface in the Southern Alps of New Zealand: characterising cloud effects on incoming shortwave, longwave and net radiation. Int. J. Climatol., doi:10.1002/joc.4014.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

32

research - A tool for avalanche risk forecasting // marwan katurji - Dept of geography, university of canterbury

Towards an avalanche-risk forecasting tool for the Southern Alps – New Zealand Marwan Katurji1 , Sascha Bellaire2, Tobias Schulmann1, Andrew Hobman3 1Center of Atmospheric Research, Dept. of Geography, University of Canterbury, New Zealand.

Email: marwan.katurji@canterbury.ac.nz 2Institute of Meteorology and Geophysics, University of Innsbruck, Tyrol, Austria 3New Zealand Mountain Safety Council, Christchurch, New Zealand In the Crystal Ball edition of June 2014 (page 12) we presented a research plan for developing a coupled avalanche-risk forecasting tool for the Southern Alps. Stage one of this project required the fine tuning of the weather model and testing its ability to simulate past precipitation events.

This study has advanced since then and we were able to test our numerical weather model’s ability in predicting the snow precipitation amounts for a 10-day period between July 4 and July 13, 2013 for the Craigieburn Range area. During this period about 50 cm of new snow was observed at Porter Heights Ski Area, whereas the vast amount (~38 cm) was related to a single storm on July 6, 2013 (Figure 1).

Figure 1. (left) A snap shot from MODIS for the post storm period shows the extent of snow cover on the ground

The Advanced Regional Prediction System (ARPS) weather model – on a 1 km grid resolution – was able to simulate the 24-hour precipitation distribution during this period with fair accuracy (Figure 2).

SNOWPACK simulations were performed using the new snow density parameterization forced by ARPS surface meteorology as well as fixed densities of 100, 75 and 50 kg m-3. The model was capable of reproducing total amounts of 25, 33 and 41 cm of snow, respectively. Although more investigation and simulations for a longer period are required we believe that these initial results, using a coupling between ARPS and SNOWPACK, show a promising potential to become an operational forecasting tool for New Zealand’s warnings services. The next stage will be to reproduce the snowpack physical profile evolution and prepare the system for forecasting capabilities.

Figure 2. (below) 24-hour cumulative precipitation in mm for July 6, 2013 for ARPS simulations on a 3 km and 1 km grid, respectively. Enhancing modeled spatial resolution from 3 to 1 km allows for resolving spill over precipitation over the main divide.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

33

research - Projecting future snow cover and runoff // jobst a.m. - Dept of geography, university of canterbury

Developing a robust projection of the future snow cover and runoff in the Clutha catchment JOBST A. M., CULLEN N. J., KINGSTON D. G., Department of Geography, University of Otago, PO Box 56, Dunedin, New Zealand The water resources of the Clutha catchment possess a great economic value for the Otago region. Water in its liquid state is used for hydropower production and irrigation, while winter tourism depends largely on the seasonal snow cover. Determining the controls on snow cover and runoff in the future is critical for those in the Clutha catchment, which is only achievable through careful modelling. In an effort to achieve this, a fully distributed hydrological model (WaSIM) is being implemented for the entire watershed (Figure 1).

The model runs on a daily time step and hydrological processes are computed at a resolution of 1km2. It contains a dynamic glacier model and offers multiple routines to simulate snow melt, which will allow changes in snow cover to be carefully assessed for all ski areas in the catchment. The climate network is sparse with very few sites in the upper catchment and no continuous high elevation data, which makes the interpolation of precipitation and temperature a challenging task.

Data were obtained from various authorities (NIWA, ORC and Avalanche NZ) and assimilated into a single database. A spatially and temporally variable lapse rate model was combined with a trivariate spline interpolation to approximate daily maximum temperature realistically in the domain. To account for processes that influence minimum temperature, such as temperature inversions that form due to cold air ponding, an inversion model was implemented in the interpolation routine. Some station data were withheld and used as independent validation sources to assess the accuracy of the generated fields.

Whilst accurate temperature estimates are essential for the realistic simulation of processes such as snow accumulation and melt, the water volume is largely driven by precipitation in the headwaters. Therefore, a 30year rainfall normal surface (forcing a trivariate spline) was iteratively adjusted and validated through a water balance approach, which has allowed a realistic simulation of the water balance to be modelled, as well as daily and monthly flows in the individual sub-catchments of the Clutha.

Figure 1: Map showing the key sites in the study domain.

Importantly, the methods used have provided a robust framework to characterize the spatial and temporal variability of temperature and precipitation at high elevations in the catchment, which should be useful for snow forecasters in the future. The modelling framework is now ready to be used to assess the impacts of climate change on snow and water resources of the Clutha catchment. An ensemble of general circulation models will be composed of which the individual projections will be downscaled to the resolution of the hydrological model. The subregional analysis will focus on changes in flow regimes (snowmelt), changes in natural storages (permanent ice, seasonal snow, lake volumes) as well as related impacts on dependent industries (hydro power, ski fields and irrigation).

It is anticipated that this research effort will provide robust and detailed projections of future snow cover in the Clutha catchment, which we believe will be invaluable for those linked to the snow industry.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

34

research - Visualising avalanche paths // simon morris Simon Morris has over 25 years of experience as a ski patroller and avalanche forecaster in New Zealand. Three years ago he began a new role as the Snow Safety Research Officer at Porter Ski Area. This winter he started a Master’s degree in snow science, looking at applications of Real Time Kinematic GPS for snow and avalanche path mapping.

Currently he lives in the quiet mountain village of Castle Hill.

As part of my master’s degree and the research I am performing in Crystal Valley, I wanted a better technique to illustrate our avalanche paths so I might show our other team members and management where the boundaries of the avalanche paths are, how avalanche paths will affect the infrastructure or ski lifts, or how an individual avalanche path is situated within our terrain. To do this I wanted to view the avalanche paths in 3D. Initially I embarked on using our geospatial software, Trimble Business Centre (TBC) to generate and view the 3D models of our avalanche paths. This software provided highly detailed 3D models but they lacked a sensation of scale and it was hard to get an impression of the avalanche path within our avalanche terrain. As a result of this, I next looked at the freeware version of SketchUp 2014 (http://www.sketchup.com/) owned by Trimble Navigation Ltd. SketchUp is a 3D modelling program and is not a geographic information system (GIS) or mapping program like TBC. You can not analyse or compile your data within, nevertheless, being a 3D modelling program it gives you more control over the visualisation of your 3D models. I found the learning curve in SketchUp very easy and it did not take long to generate simple 3D models.

There are other freeware 3D modelling programs available like Blender (http://www.blender.org/). I did try Blender for a short period but found the learning curve much steeper than SketchUp. However, Blender offers huge advantages over SketchUp in photorealistic rendering, faster modelling, realistic materials and better animation toolset.

SketchUp has a wonderful tool that lets you generate digital terrain models (DTM) straight from Google Earth by simply selecting the area you want. SketchUp will also import the Google Earth aerial photograph. I decided not to use the Google Earth DTM but opted to use our more highly accurate LiDAR (a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light data to generate our DTMs. As I was already analysing and compiling our data within Trimble software, our data was seamlessly imported into SketchUp.

SketchUp will allow you to adjust the lighting and shading of your models and this can really assist in getting a better depth of field in your models. In addition, there are plugins for the professional version of SketchUp Pro which will further enhance your 3D models. I have yet to try any of these plug-ins, but I plan to do so this summer.

After enhancing my avalanche path models as much as I could, I still felt a lack of sense of scale. So next I created several other models of our proposed ski lifts, infrastructure and Gazex system. Adding these additional models to the avalanche path models really gave a sense of scale that I was looking for. Furthermore it illustrated how everything integrated with each other.

I am still learning new tricks to get more out of the avalanche path models. Currently I am experimenting with adding rocky outcrops, adding transparent snow surfaces, to creating animations and better ways to show the avalanche path boundaries. I will continue to experiment over the forthcoming summer months.

Figure 1(below) In this 3D model, I have modelled the start zone of one of the avalanche paths within Crystal Valley. A 1m digital terrain model generated from our LiDAR was used to create the terrain surface. Next, in the model I place three standards 3m³ Gazex Exploders and one central gas shelter in their proposed positions. A Gazex system will be installed to protect both the infrastructure and a ski lift below this avalanche path. And finally to enhance the model I added some rocky outcrops and shadow effects.

Figure 1

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

35

research - Visualising avalanche paths conT’D // simon morris

Figure 2 (above) In this early experimental 3D model, I have modelled a 100 m wide strip of terrain underneath our proposed lower gondola lift line. Once more I used a 1m digital terrain model generated from our LiDAR to create the terrain surface. Next, I highlighted in red, the avalanche paths. This model illustrates the importance of correct lift tower placements.

Figure 3 A close-up view of the standard 3mÂł Gazex Exploder. These sub-models within the main model really add scale to the avalanche path or start zones models.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

36

Avalanche.net.nz Website statistics Between June 1 and September 30 2014, approximately 50,000 visits were made to www.avalanche.net.nz by over 16,300 people, with almost 150,000 pages viewed.

The percentage of people viewing the website on mobile and tablet devices continues to rise, going from 14% in 2012 to 22% in 2013, and now accounts for amost 30% of our web visitors. This translates to more than 15000 visits.

Pageviews 4000

2014 Website Visits

- Not surprisingly, spikes in visitor page views coincide neatly with storm activity. This winter daily visits peaked on Agust 14 at 3650.

3500

3000

2500

2000

Pageviews

1500

1000

500

0 1/06/2014

15/06/2014

29/06/2014

13/07/2014

27/07/2014

10/08/2014

24/08/2014

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

7/09/2014

21/09/2014

37

SOCIAL MEDIA Alongside the www.avalanche.net.nz website, we have a growing profile on social media sites. These are gaining a modest following, and serve to engage and build a community of backcountry users. They offer another way for the public to share their snow and avalanche observations. Here we describe how we use the different mediums, and what kind of following has been generated.

Facebook - www.facebook.com/NewZealandAvalancheCentre Aside from general interest posts, images and related news, we update Facebook when avalanche warnings move to HIGH. We also repost/share news and observations from the field. A breakdown of those who follow us on Facebook is below:

YouTube - www.youtube.com/user/nzavalanche

Twitter - www.twitter.com/NZMSCavalanche

In Tongariro, Canterbury and in the Southern Lakes, we have had regular video field updates on conditions. Special thanks go out to Ryan Leong and Brad Carpenter for their regular clips. Our intention is to have these weekly, and also at times when we need to get special advice out to the public. The Avalanche Centre’s videos have been very popular, and have been viewed more than 10,000 times. Field techniques and guidelines on how to perform snowpack tests are always popular.

Any posts on Twitter also get directed and posted up to our Facebook page. We use this to advise when danger levels rise to HIGH. People who follow our Twitter feed, can get automatic alerts sent to their phones as well as see this within Facebook.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

38

avalanche.net.nz //

2014 regional forecaster summaries

Avalanche ‘forecasts’ are by far the most viewed pages on the website, but last year’s introduction of the free online avalanche theory course continues to be very popular.

The large spike in numbers viewing the ‘Craigieburn’ forecast in 2013 was caused by the page being embedded into another website. Anyone viewing that host site would have inadvertently been reported as viewing ours. The bottom half of the South Island and Tongariro were the most visited, while the Canterbury region fell dramtically in the rankings, likely due to the lean winter experienced there.

Number of unique visitors to each forecast area 9000

2013

2014

7924

8000

7562 7218

7000

7198

7003 6352 6025

6000

5755

5897

5000

4651 4361

4223

4443 3905

4000

3102 3000

2000 1319

1772

1573 1287

1213

1000

1023

1147

1047 1025 442

374

0 Queenstown

Tongariro

Wanaka

Mt Cook

Key to Danger Scale Graphics: 5 Extreme 4 High 3 Considerable 2 Moderate 1 Low Report not updated that day No rating insufficient information No rating insufficient snow No rating centre closed for season

Free Craigieburns OnlineTheory Course

Arthurs Pass

Mt Hutt

Ohau

Two Thumbs

Nelson

Taranaki

Fiordland

The Backcountry Avalanche Advisories produced by the New Zealand Mountain Safety Council continue to be popular amongst recreational users of alpine areas. We consistently have more than 16,000 people regularly viewing the forecast pages to seek advice via www.avalanche.net.nz. 30% of these visitors are new to the site.

The following regional summaries cover the period July 1 to September 30 2014.

In each of the Regional Summaries we have combined graphics to help relate the following: •

the forecasted danger level for each elevation band per day

•

a blue bar graph showing number of page views for that forecast page on ‘avalanche.net.nz’ per day

•

a light blue to indicate the days when a reported avalanche involvement occurred

#

It is hoped that, ‘at a glance’, readers can see the relationship between danger levels and when people triggered and were caught in avalanches.

It should also help indicate how well people seek information (via avalanche.net.nz) on days when danger levels have increased.

# CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

39

TONGARIRO

-

// Ryan Leong

public forecaster & whakapapa snow safety officer

#

The first snow of the season came in early June to low levels from the South to South East which gave us more of an unusual distribution of snow on the ground than what we normally see at this time of the year. This didn’t last too long however, as it was followed by a sustained period of warm dry weather until late June. The sunshine was nice, but the lack of snow leading into winter started making a few people nervous.

The next weather system arrived in late June with a more ‘normal’ North West through to South West flow. It started out as rain to high elevations, further thinning out what snow was left on the ground, then got progressively colder over the following week and deposited good amounts of snow. Brief temperature fluctuations throughout the storm deposited a series of rain and rime crusts within the snow, which helped keep the snowpack relatively stable despite having over 1.5m of new wind loading lee to the Westerly half. A few small soft slabs were ski cut during the storm by ski patrol teams, but for the most part things stayed well stuck in place.

By the end of the storm (moving into the second week of July) colder temperatures had seen a small layer of facets begin to develop within the top 15 cm on Southerly half facing aspects.

Mid July saw mostly clear weather which helped develop this layer further.

From around the 21 July a good round of South West to South Easterly snowfall hit the region loading lee slopes with up to 1m of new snow. The resulting avalanche cycle produced results up to size 2.5. The standout result from this cycle was a size 2.5 explosive triggered avalanche at Whakapapa. The failure was on a thin layer of graupel which had been deposited on the previous melt freeze crust, on top of which the recent wind slab was sitting. What was interesting was not the size of the result, but the fact that the graupel layer was so evenly distributed across the entire start zone, when normally we see only isolated pooling of graupel lower down on the slope for this particular path.

Rolling into August the pattern of regular North to South West storms continued, keeping the snow safety operations busy with regular control work at both Whakapapa and Turoa. Despite the fairly consistent top ups of snow, overall coverage for the region still remained below average for this time of the season. Start zones were at threshold down to around 1500m, but it was still generally thin and picky down below 2000m.

Just when it was looking like we were heading for a season similar to last years record low snow levels a series of angry cold fronts started lining up to head over the region (and the rest of the country). Mid August bought large amounts of snow starting from the North West, and finally swinging around to the South West. By the time we had our next break in the weather it had been snowing and blowing for a week. There were a few sensitive avalanche cycles throughout the storm, but the main event was on the 16th. As the last front moved off to the East the wind swung South West and ramped up for about 12 hours rapidly reloading North East aspects with up to 4m of new snow. The strength of the wind had hammered things into place and for the most part explosive control work produced no results except for a size 2.5 slab (R4). Shortly after this a size 3 natural was observed in a backcountry start zone with similar features. Both of these results were at around 2000m in elevation and were the largest these particular paths had gone in our recorded history. Testing of similar start zones all around gave no other results. No other natural activity was observed or reported from the backcountry throughout this storm, which was quite impressive considering how much snow and wind we had.

#

The second half of August saw spring like conditions hit the region with force. A solid melt freeze cycle was the dominant feature over this period. Isothermic conditions moved as high up as 2000m and the snow levels started to recede. There was the odd flick of new snow with short lived periods of windslab instability, but nothing out of the ordinary occurred during these.

Avalanche.net.nz Unique page views - Tongariro

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

40

TONGARIRO conT’D //

Ryan Leong

September carried on in much the same way. Mostly settled weather helped further consolidate the snowpack into spring like conditions. A few fronts passed by depositing small amounts of new snow, but nothing more than 10-15cm at a time. Due to the warmer temperatures during these storms no significant instabilities developed.

Another series of cold fronts hit the region from mid September bringing rain and wet snow initially, then getting colder and delivering significant amounts of cold snow down to low levels. The winds swung South Westerly on the 22nd and the skies cleared on the 23rd followed very quickly by a rapid increase in the freezing level from around 700m to 3500m by midday.

An isolated wind slab cycle with results up to size 2.5 occurred in the morning with all results being triggered by explosives.

The rapid warming of the new snow prompted a few wet slab results later in the afternoon just outside of the Turoa ski area boundary. The first result was a size 1.5 natural which was witnessed by a member of the public, who then skied onto a similar feature and triggered a size 2 and luckily managed to ski away unscathed, but very shaken (photo below). Let’s hope this was an educational experience for the unsuspecting person.

Spring once again returned after this cycle and at the time of writing we have a strong snowpack with a good melt freeze cycle, and still good snow cover up high on the mountains. It’s looking good for some nice turns over the next few months.

It was good to see plenty of people signing up for awareness courses, as well as a full enrolment for the stage 1 avalanche course this winter. The number of people getting educated and keen to get educated appears on the rise.

Thanks go out to the snow safety / ski patrol operations at Turoa, Tukino, and Whakapapa for the consistent observations and communications over the winter. This has once again been of great assistance. Regular updates and photos of conditions from the Tonagriro crossing area also came in frequently over the start of the winter thanks to Perryn from Adventure Outdoors. It was great to have more regular updates from this part of the region. Although we did not receive as many public observations this year, it was very much appreciated when people did put something on the website, or call in to the patrol room to let us know what they saw. Keep it coming.

All the best for a safe spring.

Below: Involvement site on ‘Upper speed track’, Mangaehuehu Glacier, Mt Ruapehu. Photo Brendon Nesbit

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

41

TARANAKI

-

// Todd Cations-Velvin

public forecaster

What a winter! - promising signs came and went followed by the donning of singlets and shorts pretty quickly here in Taranaki. In brief here is a summary of how winter 2014 shaped up.

WEATHER The weather was a real mixed bag, which leaves us to wonder what late spring early summer is going to be like. Only a couple of reasonable storms produced significant snowfall which enabled the local club field to see some operational days (the lower lift sits at 1200m). The first major weather event came in mid July.

This weather system that rolled though in July brought plenty of snow to low levels allowing the local Manganui Ski Field to open with excellent blue sky skiing. The Southerly storm produced around 40cm of snow at 1200m. What seems to be a common theme for Mt Taranaki is that rain followed closely behind the storm cycle, having a dramatic affect on the lower mountain snow pack.

As we headed into August we received our last really decent storm cycle for winter, which brought snow to low levels on the mountain in that second week of August. During this storm we received 60 to 70cm of snow from the South West with strong winds. Once again following this storm was a warming period with rain showers across the mountain damping the skiers and snowboarder’s hopes of a few good weeks sliding on the mountain.

Following this last storm the weather became mainly settled in the region with warm spring time days, great for the grass growth but no good for snow users on the mountain.

A combination of rain and warm weather with the freezing level sitting about the summit on most days saw a very rapid rise of the snow line.

As I write we have seen one last little flick of winters tale with a short cold spell bringing snow to the mountain. Only problem is, the following days have been in the 20 degree temperature range.

Avalanche Activity Most storm cycles on the mountain have produced small size 1 and 2 avalanches on leeward aspects to the storms. It is unfortunate that most avalanches still seem to go unnoticed by mountain users until it is physically pointed out. The largest avalanche that has been reported for this past season happened in the famous Manganui Valley (Manganui Monster). This occurred at the end of September with a little bit of snow and a warm up period straight after the storm. It produced a wet heavy size 3 running to the valley floor.

Snow pack The early season throughout June was thin with the snow line sitting around 1600m, no significant weakness existed within the snow pack at this time due to the warmish daytime temperatures consolidating what snow we had with overnight freezes.

During the two most significant storm cycles we had in the region this year we saw instabilities within the new snow due to wind and temperature change during the storm.

Both storms provided a significant amount of snow along with strong wind transportation loading leeward aspects to the South West predominantly. This did create large areas of wind slab, which had the potential for sizeable avalanches.

Avalanche.net.nz Unique page views - Taranaki

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

42

TARANAKI conT’D //

Todd Cations-Velvin

In Taranaki we seem to experience rain and a significant rise in temps on the heels of the storm cycles. This can be one, two days or a week after the storm. This usually has a significant affect on our snow pack, diminishing the snow depth on lower elevations and destroying any weakness within the snow pack. This does provide other issues depending on the amount of rain and the rate of warm up, causing potential wet avalanches. This past winter on Taranaki did see one large wet avalanche produced from this affect, possibly more occurred but were not observed or reported.

These wet or warm conditions are what normally will provide us with slick slide for life conditions on the mountain when combined with overnight freezes.

Conclusion It has been not a bad season for snow users on the mountain with the local ski area managing a few open days during and after the two big storm cycles that hit the mountain. With this, it does seem like the winter has passed in the blink of an eye with such warm settled weather in the region, shorts and tee shirts were broken out early this year.

Be safe in what you do and seek knowledge where knowledge can be gained to enrich your life. Catch you all next winter.

Above: Hard wind slab crown wall. Photo - Ryan Leong

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

43

NELSON LAKES NATIONAL PARK

-

// Matt Wilkinson

public forecaster & ifmga guide

OVERVIEW Well what a back to front winter season 2014 was. Our 6th winter of forecasting for the Back Country Avalanche Advisory in the Nelson Lakes National Park was truly a game of two halves. Like much of New Zealand high country Nelson Lakes National Park was devoid of significant snow for a large part of the winter until spring arrived and that’s when winter seemed to start.

This winter will be remembered for having the leanest snowpack in July and most of August with an excellent comeback in September.

But 2014 will not be remembered as a season with significant snow cover at any stage of the winter. Little back country access has existed for large portions of the early part of the 2014 winter and it is expected that due to the thin snow pack that exists in the park at the start of October spring ski touring missions are going to be slim pickings. Thanks to September storms for saving what would have otherwise been a very sad winter for the snow enthusiast.

WEATHER The winter was unusually slow in getting started. This was consistent with the rest of New Zealand with very warm conditions and low snow fall through all of July. While there were a couple of snow falls during June and early July, little accumulated in the St Arnaud and Travers Ranges. Rainbow ski area opened on the 14/07/14 on machine made snow.

The shallow snow that did exist in the park below 1800m in the north and east was significantly reduced by two large rain events. One on 140713 that produced 45mm during an easterly system, and a further (rather depressing) rainfall that spanned a number of days from140730-140803 that produced a further 60mm of rain and heralded the start of August (and an impending sense of doom for those dreaming of endless powder skiing and riding). The south and western parts of the National Park did receive far more snow during this period. The snow that fell was all westerly focused with rain from the east. As a consequence the south and western parts of the National part continued to have more significant snow cover. Areas south and west of Travers Saddle such as Mt Mahanga, Waiau Pass and the head of the Durville river had more snow cover on all aspects than anywhere in the St Arnaud and Travers Ranges.

This photo is from the air, above the Waiau Pass on 18 July looking north to the terrain around Lake Constance. It demonstrates the shallow snow evident for much of this winter (and the glistening rain crust!)

Reasonably significant snow fall occurred on the 6 and 13-15 of August that allowed for some enthusiast to get further afield.

The mid and later parts of August were dry and were dominated by clear nights and cold Avalanche.net.nz Unique page views - Nelson Lakes

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

44

NELSON LAKES NATIONAL PARK conT’D //

Matt Wilkinson

conditions. Significant facets developed below the rain crust left behind from the late July and early August Rain events.

Warmer conditions then prevailed for the end of August and start of September preceding the final shift to a warm snow pack on all aspects with the mother of all rain storms on the 12 and 13th of September. There was substantial ablation of snow below 1800m over the whole park but particularly in the north and east where the snow pack was still thin.

Ready to pack up tools and go home, the warm air flow that had prevailed finally let go and turned to the southwest and a 6 day snow storm producing 100cm of snow occurred.

Unsettled conditions have continued and at the time of writing this report snow is still falling in the park with the last weekend of Rainbow ski area being open likely to be a really good one. Waxing my skis as we speak.

SNOWPACK The most significant factor in the development of this snow pack was the delay in building threshold snow cover, particularly in the north and west of the park. This meant that shallow early snow that was subjected to rain and then a long cold clear period was able to develop depth hoar. The forecasting team was concerned about subsequent snow falls and the ability of this existing snow to support any significant increase in load. This snowpack got tested twice in early and mid August. The forecast team had considerable danger posted during these storms but observations of avalanche activity were not possible in the south and west of the park.

Warmer temperatures in late August and then rain to all elevations in mid September changed the snowpack to melt form grains and cured the weakness that had existed just prior to the biggest snowfall of the winter. The mid September storm saw little avalanche activity as the snow was spread over a number of days and the existing snow by this time was comparatively warm which aided the new snow to rapidly increase in stability.

This storm provided great skiing and little avalanche activity.

To sum up; a weak snow pack that didn’t get significantly tested until it was strong!

Left: 140920 - No avalanches, just great skiing Photo - M. Wilkinson

AVALANCHE OCCURENCES Forecasting avalanche activity has been difficult this winter due to the contrasting snow cover in the south and western part of the National park, and the ability of the forecasting team to access this terrain. Occasional observations made from helicopter flights saw little activity but occurred often well after activity was expected.

The most pronounced recorded avalanche activity occurred on 28 September during a 35mm rain storm. This was predominantly loose wet activity.

TRAVEL ADVISORY Given the limited cover in the Park at this stage, climbers will be the most likely user group effected by any ongoing avalanche danger. This will be most likely from loose wet snow activity on solar aspects or on all aspects during rain events. As always appropriate rescue equipment and caution when the snow pack is unsupportive will be necessary. Due to the lack of mass in this year’s remaining snowpack, it is the forecaster’s opinion that climax spring avalanches that can normally affect DOC tracks and hut facility are very unlikely to occur.

CONCLUDING REMARKS Another forecasting season draws to a close but the forecasting team will continue until little risk of avalanche activity is likely. Travel safe and enjoy your summer.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

45

ARTHUR’S PASS NATIONAL PARK

-

// markus woertler

public forecaster & temple basin snow safety officer Overview The 2014 season started out as a lean snow year. June saw some early season snow and by early July the local ski area was hoping for a 20cm top up to open. Instead July bought a series of rain events which was followed by 367mm of rain in the first week of August. August also brought 2 snowfalls with a total of 112cm of snow.

An unusually long period of fine and settled weather then followed, which brought bluebird day after bluebird day for 3 weeks. Mid September, when the ski season was thought to be over, 2 NW systems with a southerly feed gave us the most significant snowfall of the season. This brought winter back for another week, until the 25 September, when another big rain event started and incy wincy got flushed once more Weather In general, 2014 was lean snow wise, but not precipitation wise. Temple Basin’s rain gauge saw about 772mm of rain passing by from 30/7 until the 27/9. Temperatures have been way above average and the season has been dominated by rain events. In some occasions the tail end of a storm would bring a top up of snow, but usually hardly enough to replace the loss. Many times it rained up to the tops of Mt Rolleston and Mt Murchison.

As per usual, the western parts of the forecast area experienced more precipitation than the eastern parts.

July started with a promising coverage of snow, which then got washed away by a series of rain events. The long wait for the ski season began. Temperatures were way above average with almost spring like conditions and shining tussocks at 1400m around the end of July.

By August we hoped that rain would be a thing of the past and winter would come back.

But it turned out that the standout feature of the weather for August, in Arthurs Pass National Park, was a rain event with 367mm falling during the first 6 days of August.

This turned was the heaviest and longest lasting rain event during the 2014 forecasting season. In total August saw 409mm in the precip gauge, and brought a total of 112cm snowfall on the board. Mid August was the start of an unusually long period of very settled, sunny and fine weather with hardly any clouds in the sky and barely any wind. This period continued into early September and by mid September the ski season was thought to be over as the amount of bluebird days, in combination with high freezing levels, caused a huge snowmelt and only terrain above 1600m in the westerly half remained skiable.

Finally late September saw the arrival of some unsettled weather with a series of colder storms. Over the 18th and 19th snowfall returned with storm totals up to 75cm at 1700m.

Then things turned warm quickly, as to be expected in the spring and rain began to fall again, with totals exceeding 80mm.

Snowpack With some snow on the ground mid june the snowpack started to facet especially in the southerly half. As there was only a little snow on the ground avalanche activity was limited. July’s rain events broke down most of the existing weaknesses in the snowpack.

The rest of them got wiped out by the large rains in early August, which saturated the whole snowpack causing a natural avalanche cycle. Gale force NW winds stripped some spines and ridges down to a slippery and icy surface which had had to be treated with caution. In August, some midstorm weaknesses associated with buried and well defined graupel layers on top of melt freeze crusts lingered. These layers did not cause any trouble in the end as warm temperatures and fluctuating freezing levels settled the snowpack.

The melt freeze cycle continued for weeks causing a large ablation. September 15th brought another warm storm initially bringing rain, followed by about 75cm of snow. Most of this fell on a wet snowpack which seem to have it stabilising quickly, and despite strong to gale force NW winds no major instabilities were observed.

Avalanche.net.nz Unique page views - Arthur’s Pass

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

46

ARTHUR’S PASS NATIONAL PARK conT’D //

markus woertler

Avalanche Activity Very few backcountry avalanches have been reported via the ‘report an observation’ link on the avalanche.net.nz homepage.

Most the bigger rain events were accompanied by some natural avalanche cycles. Wet slides dominated the avalanche type.

Many of these slides were only up to size 1.5. Mt Phipps and Mt Temple showed some usual activity during rain events with wet slides up to size 2. The biggest natural avalanche cycle occurred mid august during a storm cycle. Natural slab avalanches were observed on all aspects in the alpine. Natural slab avalanche up to size 3 were observed on the E and S facing slopes of Mt Philistine. These slabs happened during the storm and had crown walls of an estimated 200m length.

No avalanche involvements have been reported this season. Temple Basin ski patrol only triggered small slides up to size 2 during control work...

Travel Advisory The eastern half will continue to see a decent snow cover all the way through October. The avalanche danger will usually increase slightly during the afternoon hours with the daily warming, mainly on the solar aspects, where caution will be required when the snowpack becomes unsupportive and weak. From time to time when the freezing level rises significantly and during heavy rainfalls the danger will rise rapidly and significantly. Rain and a high freezing level over a couple of days will cause snow glide and will ultimately see big ground release avalanches continuing in October. These wet slides have the potential to run all the way to valley floor in the usual areas. Most caution will be needed during and after intense rainfalls to ridge top.

Concluding remarks The forecasting season started with the ski area remaining closed due a lack of snow. Backcountry use and information was limited during this time, and a large percentage of the information to determine avalanche danger came from the Temple Basin weather station and the Arthurs Pass stations. The season turned out to provide a good touring and climbing season with no major weaknesses lingering around in the snowpack. While 2014 wasn’t the most exciting season snow and avalanche wise we are thankful that it was a reasonably safe winter.

As the season ends I would like to thank all the backcountry users who have contributed with their data to produce this forecast.

Also a big thanks to the Temple Basin Ski Club, its regular skiers who always provide information out of the backcountry, and to Gordie Smith for some great feedback. Big thanks to Brad Carpenter who jumped in for a couple of forecasts when Temple Basin internet connection broke down. Also I would like to say thanks to everyone for putting up with my ‘germaness’ in the forecasts.

Above: A natural size 2 loose wet avalanche at Broken River on September 14th. Photo - Doug McCabe

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

47

craigieburn ranges & MT HUTT

-

// brad carpenter / ronan maguire

public forecasters & snow safety officers at Porters (brad) and Mt Hutt (ronan) The Craigieburn Range and Hutt Range forecast region experienced another low snow winter season in 2014, but we did see some interesting avalanche cycles, a fair number of human triggered avalanches, and even the odd powder day.

The beginning of the 2014 season was marked by early snowfall in May, followed by the two very dry months of June and July. Much of the snow that was still on the ground by late June was to be found in protected bowls and shaded southerly aspects above 1750 metres.

These areas clutched onto a very shallow snowpack that surprisingly provided some great early winter powder skiing for the motivated recreationist.

Brad

# Ronan

#

#

Above: Powder turns in early July could be found in sheltered areas above 1750m like Tarn Basin near Mt. Cheeseman. Photo - Brad Carpenter

With good snowmaking weather Mt Hutt Ski Area was able to open by middle of June, and Porters Ski Area opened its doors by early July. These two areas provided most of the backcountry access for the next few weeks.

# #

From August 3rd to the 13th a dishearteningly robust northwest rain storm kicked off our first major avalanche cycle of 2014. From July 29th until August 4th Broken River in the northern end of the Craigieburn Range recorded 159mm of rain, Porters Ski Area in the south end of the range reported 102mm of rain, and Mt Hutt Ski Area recorded 7mm of rain and 40cm of storm snow.

Prior to this first rain on snow event our shallow snowpack had been quietly

Avalanche.net.nz Unique page views - Craigieburns / Mt Hutt

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

48

craigieburn ranges & MT HUTT conT’D

// brad carpenter / ronan maguire

faceting away on the cold ground. For many weeks a rime crustfacet combination (Photo Left) that formed near the ground was showing very high propagation propensity in extended column tests.

This rime crust-facet combo was mostly seen towards the southern end of the Craigieburn Range and in the Hutt Range where big, whumpfing collapses and long shooting cracks were being reported.

In some areas this crust had become buried by light new snowfall followed by moderate wind transportation that created new isolated wind slabs.

The 40cm snow event at Mt Hutt created new thick wind slabs atop this rime crust-facet layer. With this additional new load on a hair trigger crust the ski patrol at Mt. Hutt started knocking down wind slab avalanches up to size two with explosives (Photo Below).

Above: A rime crust with developed facets found below it, failed consistently under a skiers weight and in extended column tests. This crust-facet combo became more of a problem for the Hutt Range.

Photo - Brad Carpenter

Below: Wind slab results from Explosives at Mt Hutt Photo - Ronan Maguire

It was during this period that a ski patroller took a harrowing ride during avalanche mitigation on a size two wind slab, but was left mostly unharmed.

The large amount of rain that fell in the Craigieburn Range during the beginning of August caused many loose wet slides on steep south and east facing areas in the Craigieburn Range. There were also two noteworthy wet slab avalanches that occurred around the middle of the storm: a natural, size two, wet slab avalanche at Broken River Ski Area on August 2nd, and a natural, size three, wet slab avalanche from Hamilton Peak also on August 2nd (photo below left).

Left: Size 3 wet slab off Hamilton Peak. Photo - Nick Jarman

Both avalanches occurred on east aspects. A third, very large avalanche was recorded on August 7th in Crystal Valley in the southern end of the range. This slide was a natural, size four, storm slab (or possibly a wet slab) avalanche that occurred on a southeast aspect and was presumed to have occurred a few days earlier during the middle part of the storm.

Our first accidental human triggered avalanche occurred on the afternoon of August 5th also in Crystal valley when a snowboarder triggered a size one wind slab on a northeast aspect in an isolated area with relatively high consequences. The snowboarder was carried a few metres but was able to escape off of the slab without serious incident.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

49

craigieburn ranges & MT HUTT conT’D

// brad carpenter / ronan maguire Explosives triggered a size 2.5 wind slab avalanche at Porters Ski Area on September 17th.

Photo - Simon Morris

The beginning of August marked the end of well over a month of purgatory for the club fields. Towards the end of the five day rain storm the region began to see some colder temperatures and the snow started falling with an average of sixty centimetres of new storm snow having accumulated in upper elevations by August 13th. The new snow helped to boost all of the local club fields into opening status and user numbers in the backcountry increased dramatically, the majority of which were observed in the backcountry areas just outside of the ski fields.

Skier and snowboarder triggered avalanches began to occur during this time as well. The weather during the remainder of August and into early September stayed cool, calm, and sunny as a massive high pressure system in the Tasman Sea blocked all hopes of any snowy weather making it into our region. Cold clear days and nights created high temperature gradients in the top half of our snowpack.

During this period we began to redevelop a new continental style snowpack, and with it a persistent slab problem. Early on observers in the central and southern Craigieburn Range and the Hutt Range started to see moderate to hard failure results in profile work from a crust-facet combination, but an explosives triggered avalanche in the northern end of the Craigieburn Range may have provided the first solid evidence of a persistent slab problem.

On August 12th the Craigieburn Valley ski patrol were able to release a size two, persistent slab with a one kilogram hand charge. The avalanche measured sixty metres wide by one metre deep and occurred on an east aspect. It was found that the failure plane consisted of 1mm facets on a melt-freeze crust. The crust-facet layer that was being found in the central and southern parts of the Craigieburn Range and in the Hutt Range was also seen at similar depths and showed planar failures on 1-2mm facets on a melt freeze crust in many of our isolated column tests . It started to look like it was a matter of time and new load, before we would start seeing a widespread persistent slab avalanche cycle in the region.

On September 6th a snowboarder triggered a loose wet, size one and a half avalanche in the southern end of the Craigieburn Range as temperatures warmed significantly towards the end of the pernicious high pressure period. The avalanche was triggered from a north facing slope at 1900 metres, but luckily again, the snowboarder was not caught in this slide that travelled nearly 300 metres through some heinous terrain features.

A new round of northwest and southeast fronts followed the short-lived warm-up and dumped up to fifty centimetres of new snow onto upper elevations of the Craigieburn region from September 15th to September 23rd. Mt Hutt saw around fifteen to twenty centimetres of new snow during the same period. From September 13th to the 14th the region was again treated to a pre-snowfall northwest weather system that gave our cold dry snowpack and persistent slab problem ample time to warm up and effectively broke down the persistent weak layers we had been worried about. Phew! An average of 15mm of rain was recorded in both the northern and southern ends of the Craigieburn Range. Mt. Hutt saw minimal precipitation in the form of rain, and no avalanches were recorded to have failed on the crust-facet layer. The concern for loose wet or wet slab avalanches combined with poor weather caused all of the ski fields in the area to close during the peak of the rain event, and natural size one to one and a half loose wet avalanches were observed throughout the Craigieburn and Black Ranges.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

50

craigieburn ranges & MT HUTT conT’D

// brad carpenter / ronan maguire

The temperature finally cooled enough by September 15th to allow for snow, and from the beginning of this new storm cycle ski patrols at all of the operating ski fields were able to trigger storm slabs and wind slab avalanches up to size two using explosives and ski cuts. Huge new cornices were observed on south and east aspects in the Craigieburn Range as well. Many smaller natural cornice failures were observed during the storm, and a natural size two wind slab avalanche was triggered by

Left: On September 19th a large cornice failure triggered the slope beneath it in a backcountry bowl in the southern end of the Craigieburn Range.

Photo - Tony Phillips

Below: The avalanche from September 19th occurred in a very popular backcountry skiing area.

Photo - Luke Armstrong

a large cornice failure in the southern end of the range (photos below).

On September 21st a backcountry skier triggered, but was not caught in a size two wind slab avalanche from the southeast aspect of Mt Cloudsley in the Craigieburn Range. By September 23rd a wave of warm northwest air began wreaking havoc on the snowpack and the skiing quality, and most ski areas were racing the clock and the weather to reach their respective October closing dates.

We continued to see more and more backcountry enthusiasts in the Craigieburn and Hutt Ranges this season and received heaps of observations from the public including avalanche observations, snowpack profiles and skiing condition reports. It is one of our highest priorities to understand who is recreating in our forecast area, how to involve these user groups in the regional forecasts and continue to positively build on the relationships that we have. The five short YouTube videos for the website that were produced by the end of September received a lot of great comments from folks about the effectiveness of this type of media outreach, and we plan to build and expand on the video clips for next season. We also continued to foster other links to our user groups via informal Facebook groups like Canterbury Ski Touring, and The New Zealand Alpine Club for example, and this is just one type of networking where we feel we can reach more users.

The Craigieburn Range and Hutt Range avalanche forecasters augment their daily observations with the Info-Ex entries from six ski operations around the region. A big thank you goes out to all of the regularly contributing ski field snow safety and ski patrol teams and local guides including: John Hooker, Mike Ward, Jamie Robinson, Doug McCabe, Andrew Dennis, Brian Pollick, Forrest from Mt Olympus, and Anna Keeling.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

51

AORAKI / MT COOK

-

& ohau, two thumbs // public forecasters & ifmga guides for alpine guides ltd

Trev Streat / Dave McKinley

The 2014 Aoraki / Mt Cook winter season snowpack and conditions can broadly be divided into five periods.

# Gardiner Hut

#

#

#

ROWDY. 1st to 13th July The early June period saw moderate to strong winds from all directions, snowfall or rain 9 days out of 13 and wide fluctuations Dave in the freezing level. At the end of it all we were left with a highly variable snowpack with respect to layering and distribution.

At high elevations near the divide things were pretty fat on sheltered slopes, but the usual tapering of snow depth with elevation and distance east of the divide was much more pronounced than usual. Thanks to a good drop in wind and Trev temperatures at the end of the weather cycle there was a nice 30cm layer of cold powder disguising the rain crusts and wind pack below.

Avalanche obs during the period were limited due to the weather.

A number of slabs to size 2 on E and S aspects were seen on the 15th along with a size 3 slab near Endeavour Col that was probably related to the rock fall that got Gardiner Hut. Numerous loose small snow slides had run on western aspects. Other avalanching probably occurred earlier but was subsequently disguised by wind and snow.

Snow tests on the 15th returned moderate to hard resistant planar (RP)results. No significant shears were noted and snow strength generally increased with depth.

Key layers were the July 13th rain crust and the 30cm of cold dry snow just above that was to cause problems later on.

COLD 14th to 27th July A period of cold weather with relatively low freezing levels, predominantly SW winds and a few light dustings of snow occurred late July. Snow stability trended towards good apart from a few short-lived phases of concern with SW windslab. No fresh avalanching was seen apart from a bit of sluffing and a tiny ski cut slab. Surface hoar and near surface faceting became increasingly well developed as time went on and the main concern was how this weak surface snow would react once buried.

CLASSIC 28th July to 13th August This period saw a return to classic Mt Cook weather, a big NW storm lasting 6 days. 360mm of rain in the village, rising freezing levels and strong winds followed by a sharp drop in temps with a SW change bringing snow to low levels.

Fine weather on the 4th allowed some observations; The July facets had been destroyed up around the divide but were notably reactive to snow tests and skier traffic out to the east of the Malte Brun range where they lay buried 60 to 170 cm down in the pack. Ski conditions were very good.

Widespread slab and loose snow avalanching had occurred during

Avalanche.net.nz Unique page views - Aoraki/MtCook

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

52

AORAKI / MT COOK

& ohau, two thumbs

// Trev Streat / Dave McKinley

conT’D

Above: 11th August Aoraki/Mt Cook region. Photo - Trev Streat.

the storm on all aspects with some size 3 events on S and E facing slopes. Skiers in The Gammack range remotely triggered a solid size 2 slab that released about 100m above and to one side of the party. One skier was caught by the avalanche but not buried.

The 6-day dump was quickly followed by two smaller storms. The first delivering 60mm out of the West/SW, only resulted in a few small slabs up on the divide. The second and final storm before the drought came from the NW. 80mm fell with a 1500m freezing level. This one produced a few more slides than the first with some obvious ‘step down’ fracture lines into the facets.

Snow quality was briefly excellent…..

DROUGHT 14th August to 11th September Unfortunately the beautiful snow conditions experienced at the end of the ‘classic’ period were soon obliterated by a couple of days of strong SW winds with no precipitation. Despite significant snow redistribution no fresh avalanching was observed at Mt Cook.

Two small skier triggered slabs ran in the Round Hill backcountry on the 15th on buried facets.

At Cook the 28th July facet layer continued to react to tests but was observed to be gradually gaining strength, both within the layer itself and in the bridging effect of the stiff wind pressed snow above. By the 22nd August snow tests on the facets produced hard RP results on slopes that had previously been highly reactive and the chance of triggering on the layer was becoming increasingly remote.

A fresh round of near surface facet development on shady slopes began during the drought and over time some slopes that previously had tough skiing on breakable crust came back into surprisingly good condition.

On the 3rd Sept a ski tourer in Sawyer stream triggered two small slabs, size 1 and 2 SE aspect 1750m, in a spot where recent localised down slope windloading had built a shallow slab over surface facets. This was probably an anomalous event, similar conditions were not observed on other comparable slopes.

Not much else happened during the latter stages of drought apart from continued faceting on shady slopes and the steady deterioration of snow bridges up on the glaciers. After a day of rising NW winds the drought broke rather unimpressively on the night of 11 Sept with 2mm of rain in the village.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

53

AORAKI / MT COOK

& ohau, two thumbs

// Trev Streat / Dave McKinley

conT’D SPRING 12th to 30th September “the Top Ups” Getting better. From the 12th to the 14th there was 42mm of rain and a freezing level around 1800-1600m, low enough to be useful and little to no wind. On the 14th through to the early hours of the 17th there was another 65mm in the village and reports from hut bound guides at the head of the Tasman and Murchison of 1m plus new snow of excellent quality but a hollow feel in the new/old interface. It speaks volumes when highly experienced ski addict/guides are too nervous to ski the Murchison hut slopes in epic powder!

A day later all has settled. Yeah right! A skier accidental (sz 1.5) slab released in the drop in to Lake dumbbell, Ohau, about 40 down on a southerly aspect.

Still light winds but by 21st we had another 45mm with the tail end bringing the odd flake down to village level and a wind shift to the south started to shift some snow lee to the south making for an interesting spread of aspects to be wary of. ie, all of them. Really high quality skiing to be enjoyed, although the use of a white cane may have been useful at times.

Although the next few days did have a bit of wind transport from the south then later the west, there seemed to be quite good settlement and on investigation the previous layers of concern were not reactive.

Towards the end of the month there was a noticeable spike in temperatures and the precipitation that came in late on the 25th fell as rain to well above 2000m until late in the cycle on the evening of the 26th when it cleared and the saturated near surface snow began to lock up, from then on classic spring conditions have prevailed.

Officially the end of the season on the last day of September, as often is the case the skiing/riding is just sublime with a bit of dust on crust, but mostly leisurely starts and prime corn runs. Snow line still down to Sealy Tarns (1400m)

alpine and avalanche resources

Avalanche Awareness $30.00

Avalanche Handbook $45.00

Avalanche Assessor Card or Rescue Card $11.99 each

Alpine Skills $20.00

NZ Guidelines and Recording Standards for Weather, Snowpack and Avalanche Observations (2011, NZ) $30.00

Card Combo (both cards) $19.99

To purchase any of these resources online, please visit www.mountainsafety.org.nz/resources

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

54

WANAKA

-

// Simon Howells

public forecaster & snow safety officer at treble cone The 2014 season produced snow in pretty limited quantities it has to be said and this in turn, led to a quiet few months as far as avalanche activity was concerned. On a positive note, this situation ensured that human involvements were rare and there were no serious injuries reported.

In the early weeks of the season, the storms which pushed through were just as likely to produce rainfall as snow, and as a consequence, by mid June the cover remained thin and patchy especially in the SE portion of the region were most of the back country use occurs.

In late June and early July we experienced further wet weather with rain to well over 2000m on several occasions. This weather pattern created a pack which was generally shallow and contained multiple crust layers.

# #

In late July, a Southerly flow ensured a spell of cold, clear weather and the rapid development of facet layers. Fortunately, it was not cold enough for long enough to promote the widespread growth of that most sinister of buried weaknesses - depth hoar. Nevertheless, at the end of July the pack was thin and weak with a number of facet layers sandwiched between stout melt freeze crusts.

In the final few days of July, a NW storm cycle led to overloading and the first significant round of natural and human triggered avalanches. One of the few human involvements of the season occurred on the 26th of July when the second rider in a heliski group (operating in the Harris mountains) initiated a remote which cracked 50m above the other members of the party on an East facing slope at 1900m. Three people were carried on top of moving blocks for about 50m but thankfully no one was seriously injured or buried. The failure plane consisted of facets sitting above the July 13th melt/freeze crust. On the 29th of July a skier accidentally triggered an avalanche on a SE aspect at approximately 1800m and once again, the weak point proved to be a facet layer resting on a melt freeze crust.

It appeared that the sorely tried collective patience of the ski and snowboard community may be rewarded when it started to snow in the opening week of August with almost a meter of snow falling between the 31st of July and the 3rd of August at 1900m. Much of this snow arrived without wind and as a result, it was not immediately hammered into hard slab. Perhaps the high altitude rain events and severe gale NW winds of the early winter could become an unpleasant but distant memory? A Southerly flow produced further snow on the 7th and 8th of August but unfortunately, these falls were accompanied by gale force winds from the Southerly 1/4 and much of the surface snow was pounded by the wind or scoured. During this period, temperatures remained cold and the snowpack generally thin and weak, but wind loading was not sufficient to initiate a widespread avalanche cycle.

On the 11th of August, a NE storm delivered almost 30cm at 1700m. A small quantity of snow (8-10cm) fell on the 12th of August and this date turned out to be of special significance as it marked the last time we were to enjoy snowfall for a month. Strong West to SW winds led to the formation of wind slab and natural activity was reported by heliski operators in the Central Harris and in the area around Black Peak. Most of these avalanches were recorded as soft slab failing on steep slopes lee to the Westerly 1/2.

Avalanche.net.nz Unique page views - Wanaka

In the last two weeks of August, skies were mostly clear and winds light and predominantly from the Southerly quarter. Temperatures remained cold and as the snowpack was still relatively shallow in many places, facet development continued particularly on the South facing slopes.

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

55

WANAKA conT’D

// Simon Howells

As August drew to a close, the North facing aspects began to exhibit more spring like characteristics and melt/freeze crusts became widespread. While the solar aspects were beginning to show signs of daytime warming, the Southerly weather pattern ensured consistently cold overnight temperatures and deep freezes. As a result, the snow surface even on solar aspects was typically slow to unlock and wet slide activity was limited. A handful of small wet slides were reported and these tended to be confined to very steep, unsupported slopes with large areas of surrounding rock driving rapid heating. With the seemingly endless succession of fine, mild days, the main hazards for back country users became “slide for life” conditions and risk of severe sunburn.

The first two weeks of September continued in the same vein as late August with fine settled weather which was all very pleasant, but the lack of storm activity and new snow was beginning to exasperate many people. The snow drought finally broke on the 12th of September with more falling on the 13th. Only a small quantity arrived (10-12cm) but as it fell with little wind it was extremely welcome. On the 16th, a significant amount of snow (25cm at 1750m) arrived from the West with light winds.

Unfortunately in the days following the 16th the wind picked up dramatically from the Westerly half. In general, these winds tended to scour slopes rather than build hazard and very little avalanche activity was reported. In the closing couple of weeks of September, the fine weather returned and temperatures remained reasonably cool.

Wet slide avalanches have been a rarity this Spring for a number of reasons. The solar aspects have only held a thin cover this year at the best of times. Very few rain events have occurred since July and the heavy falls which we would normally experience in Spring have simply not arrived so far.

Also, we are still seeing solid freezes most nights and relatively cool temperatures during daylight hours and thus the pack has been slow to soften on most occasions.

In closing I would like to thank all the people who have contributed observations and information to the INFOEX during the season - I hope you are all able to get out for some skiing or riding this Spring.

Above: View of Black Peak (foreground) and Mt Aspiring (behind) taken from Towers ridge, adjacent to Treble Cone Ski Area.

Photo: Gordie Smith

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

56

QUEENSTOWN // Chris Cochrane

-

public forecaster & senior lead guide at harris mtn heliski

OVERVIEW It seems looking back over five previous season reports there is always some record breaking event, you guessed it, this season was no different for setting new records. Not a great season for snow I am afraid to say, with not enough snow below 1000 m to produce a forecast this year. This is the first time I can remember this happening, hopefully not a sign of things to come.

# # #

#

WEATHER There was very little in the way a natural snow for ski-fields to open the season with several delaying their opening in hope of more snow.

Without machine made snow several areas would not have opened until very late in the season. Backcountry areas were limited to summit areas for snow. Mid July there was a significant warm rain event that had many skiers/boarders wondering if we would get a winter.

Fortunately snow began to arrive in dribs and drabs as the snow base began to build, with some significant falls in early August. The biggest fall of the season was 30cm on the 5th. Unfortunately that was about it, literally! This is where a new record was set for this region. It was the longest spell of fine weather ever recorded for the Queenstown region, over 30 days without a flake of snow...unbelievable! (But true).

Snow again fell in early September, nothing significant. A few fields shut up shop early as the season stuttered to a close.

SNOWPACK As stated earlier there was not enough snow at lower (1000 m) elevations to generate a forecast. The July rain crust stayed within the pack for much of the season and was the sliding layer for many events throughout the mid season. After the early August snowfall we had 4 days of relentless SW gales. Avalanches reported during these winds were some of the largest seen in this areas for over a decade. Several size 3 avalanches at the Remarkables, one hitting and partially burying the base building. It was a similar story in the backcountry with very large events reported.

Really with the incredible stretch of fine weather the snowpack settled quickly and there was little if no change in the snowpack for the best part of a month. Temperatures remained cold for a very long time, the quality of the ‘spring corn’ was poor as there was very little melt/freeze, it was more a matter of moist powder. Northern aspects were losing snow rapidly. Southern aspects however held onto good faceted (frost dried) winter snow.

The first few weeks of September were some of the best conditions for backcountry touring, all together though this was a frustrating season in general.

Avalanche.net.nz Unique page views - Queenstown

#

denotes days when involvements occurred

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

57

QUEENSTOWN conT’D// Chris Cochrane

Above: Yes it happens here too! Steve Maluschnig and Dave Pickard inspect a natural slab release adjacent to the cross country ski trails on the Pisa range July 17.

Photo: Gordie Smith

AVALANCHE OCCURRENCES July was the month that we saw the most involvements with 8 people caught in various events (most size1); however there were no burials. A very large avalanche in the Remarkables’ backcountry resulted in a full SAR event. Search dogs cleared the site and whoever triggered the slide had escaped. In mid August the avalanche rating was High and backcountry users were well behaved and stayed clear of avalanche zones. The avalanches reported around this time were huge so perhaps the word is getting out there. Heliski operators triggered 2 separate events that were up to size 2.5 but no one was caught. Most avalanches this season were in the size 1 category, a reflection of the lack of snow. No spring events were recorded.

Above: September 29 in the popular backcountry haven of Wye Creek, over the back of the Remarkables.

Photo: Gordie Smith CONCLUSION Last season we had an Easterly weather pattern with much of the snow coming from this direction, conversely this season there were virtually no Easterly events. This season there was a more continuous SW flow which kept the snow cold (not much spring corn).

Just a note for backcountry users, it’s not a crime to trigger an avalanche. The search and rescue (SAR) event behind the Remarkables ski area was an expensive and time consuming exercise with Police, dog handlers and helicopters. If you trigger an event, please tell someone or go to the avalanche.net.nz web site to share your observation. Not only are you becoming part of information sharing community you may also be preventing an expensive call out.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

58

niwa 2014 winter climate summary // Chris Brandolino

- NIWA Forecaster – NIWA National Climate Centre

Kindly reproduced with permission from NIWA

A mild winter for much of the country.

Temperature It was a mild winter for much of the country, but especially for the South Island where winter temperatures were predominantly above average (0.5 to 1.2°C above average). The exception was parts of Central Otago, where winter temperatures were well above average (more than 1.2°C above average), and isolated parts of mid-Canterbury, where near average winter temperatures were observed (within 0.5°C of average). Winter temperatures were above average or near average across the entire North Island.

Rainfall There was a notable dichotomy of winter rainfall anomalies experienced within both the North and South Islands. In the North Island, winter rainfall was well above normal (more than 149% of normal) throughout Northland, yet it was below normal (50-79% of normal) for a number of central, eastern and southern parts. In the South Island, winter rainfall was above normal (120-149% of normal) in Arthur’s Pass, Mount Cook National Park and Wanaka. In contrast, winter rainfall was below normal for the majority of the eastern South Island.

Sunshine Winter sunshine was abundant for much of Waikato, North Canterbury, the Mackenzie Country, the Southern Lakes and Central Otago where winter sunshine was above normal (110-125% of normal), and in some cases well above normal (more than 125% of normal). In contrast, parts of southern Wairarapa received below normal winter sunshine (75-89% of normal).

Overview Overall, winter 2014 was characterised by mean sea level pressures that were higher than normal over and to the west of New Zealand. This resulted in an anomalous westerly flow across most of the country with the exception of the north of the North Island where anomalous easterly flow occurred. These westerly and easterly flow anomalies respectively contributed to the difference in rainfall anomalies observed across New Zealand during the season, with eastern parts of the South Island observing a drier than normal winter and Northland observing a winter that was much wetter than normal. Notably, it was an exceptionally warm start to winter. In June 2014, a north-easterly flow anomaly dominated across the country, and this was a contributing factor to what was New Zealand’s warmest June on record.

As noted above, winter temperatures across the country were mild overall. The season started out extraordinarily warm, however temperatures returned to near-normal in July and August. Winter was especially mild for the South Island where temperatures were predominantly above average (0.5 to 1.2°C above average). Additionally, some parts of Central Otago observed winter temperatures that were well above average (more than 1.2°C above average). An exception was isolated parts of midCanterbury and coastal Marlborough, where near average winter temperatures were observed (within 0.5°C of average). In the North Island, winter temperatures were above average in parts of Northland, Auckland, Waikato, Bay of Plenty, Gisborne, Hawke’s Bay, Manawatu and Wellington, with near average temperatures across the remainder of the island. The nation-wide average temperature in winter 2014 was 9.1°C (0.8°C above the 1971-2000 winter average from NIWA’s seven station temperature series which begins in 1909).

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

59

niwa 2014 winter climate summary conT’D// Chris Brandolino

- NIWA Forecaster – NIWA National Climate Centre

There was a notable difference in winter rainfall anomalies experienced within both the North and South Islands. In the North Island, winter rainfall was well above normal (more than 149% of normal) throughout Northland, yet rainfall was below normal (50-79% of normal) in southern Waikato, Hawke’s Bay, Manawatu and the Kapiti Coast. In the South Island, winter rainfall was above normal (120-149% of normal) in Arthur’s Pass, Mount Cook National Park, Wanaka and south-western parts of Southland.

In contrast, rainfall was below normal for large parts of the eastern South Island. Areas around Blenheim, Kaikoura, Christchurch, Timaru and Dunedin only received approximately half to two-thirds of normal winter rainfall. Winter rainfall was near normal for remaining areas of the South Island.

At the start of winter, soils were drier than normal for parts of Northland, Auckland, northern Gisborne, the Central Plateau and Hawke’s Bay, whereas they were wetter than normal throughout the eastern South Island, the Southern Lakes and Central Otago. As of 1 September 2014 soil moisture had returned to near normal levels for large parts of the country. The exception was parts of Taranaki, the West Coast and Tasman as well as the districts of Selwyn, Waimakariri and Timaru, where soils were slightly drier than normal for the time of year.

Winter sunshine was abundant for much of Waikato, North Canterbury, the Mackenzie Country, the Southern Lakes and Central Otago where winter sunshine was above normal (110-125% of normal), and in some cases well above normal (more than 125% of normal). In contrast, parts of southern Wairarapa received below normal winter sunshine (75-89% of normal). Remaining areas of New Zealand observed near normal winter sunshine totals (within 10% of normal).

Figure Left: Winter 2014 mean temperature expressed as a difference from average, illustrating that mean temperatures were higher than average for many parts of New Zealand.

Mean temperatures were above average for many parts of the North and South Islands (0.5 to 1.2°C above winter average – yellow shades), with mostly near average mean temperatures recorded elsewhere (within 0.5°C of winter average – green shades).

Click link below to read the full report: Winter 2014 Climate Summary

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

60

Ski patrol training in New zealand // q & a with staff and students at tai poutini polytechnic Looking for a challenging job in an often stunning and dynamic environment? Then Ski Patrolling could be the way to go.

The days of local ski bums with a first aid certificate, coming up through the ranks and learning on the job appear to be dwindling fast. Most new patrollers are now entering the industry having fast tracked their learning by completing the season long course run by Tai Poutini Polytechnic (TPP) based in Wanaka.

Above: Vindy (left) and Robbie stoked to be entering the industry Photo: TPP

TPP’s Ski Patrol training is the new default, trusted by industry for turning out well-rounded graduates ready to take on the challenges of the mountain. Lead Tutor Karen Boserio – better known in the industry as Boz – says part of the programme success is the close contact with industry. As a result, she has local and Canadian ski areas clamouring to snap up graduates each year.

TPP has relationships with ski areas right across New Zealand, with every student completing a four to five-week work experience placement on the mountain. Former TPP student and current Remarkables assistant snow safety officer Jim Young says the students Boz sends his way are always well-prepared and ready to go, but there’s a lot the mountain still has to teach them.

“Ski patrol is a varied operation. Students may be called upon for hazard identification, rescues and avalanche control – a whole spectrum of skills – it speeds things up heaps if they are already trained for this. The best thing that anyone could ever do if you’re serious about a career in ski patrol, is do the TPP course. There’s no two ways about it.”

Jim says Ski Patrol is more a lifestyle than a job and the Remarkables crew is a tight-knit bunch.

“You need to be able to deal with pretty much anything the mountain can throw at you. Ski patrol is for someone that can think on their feet and enjoys working in a team, and working hard. It helps to have an intrinsic ability to problem solve and the work you get to do is in a fast paced and dynamic environment.”

The nature of the job – keeping the mountains safe for staff/guests and rescuing those who do get into trouble – makes it incredibly challenging and hugely rewarding. Jim knows the thrill of a successful rescue, as well as the despair when the worst happens. He says there’s no feeling like opening the field after a big snowfall, with thousands of people waiting in anticipation. He also enjoys the teaching aspect of working with TPP students and preparing them for a future on the mountain.

This year, students Robbie Willliams (26) and Vindy Hamilton (19), were taken under the wing of the Remarkables ski patrol crew for their five week placement.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

61

Ski patrol training in New zealand conT’D // q & a with staff and students at tai poutini polytechnic

“Day one was a stand-out,” says Robbie. “We began with a 6am start after a four day storm delivered 80cm of new snow. This is where the course is so awesome. Because we had trained we could start straight away working with explosives, hands-on out there under the guidance of the crew.”

Robbie had worked as a registered nurse in Australia before learning to ski in Canada. It was there that he got talking to a former TPP student about ski patrol and he decided to move back to New Zealand to do the course.

Above: Robbie checking temps in the Stevensons screen

“When I decided that’s what I wanted to do I did a lot of research, and I chose TPP because it offered the most dedicated training to become a patroller.”

Vindy says he wanted a job in the mountains and had heard about the TPP programme at a careers expo at high school.

Above: Vindy getting some time in the horns

He says the training set him up for work experience and his five weeks at The Remarkables were fantastic. “The Remarkables is an awesome ski field with amazing terrain. It was go, go, go from the beginning and the crew was very supportive. We leant all sorts of skills on the course, and then getting to apply when we came out here on work experience helped heaps to reinforce what we had learnt. It’s also a great way to show what you can do and perhaps get your foot in the door”.

Above: Vindy with tutor ‘Boz’

Internationally, New Zealand is considered a great starting point for a career in ski patrol. Remuneration is comparatively good and you get a solid grounding experience which you can take overseas.

TPP has been running the ski patrol programme since 1995 using notable industry icons such as Dave Crow, Ed Nepia, and Russell Braddock to lead the training. Now with Boz at the helm they continue to work closely with fields like The Remarkables around the country to turn out well-trained graduates who are snapped up by the industry.

Next intake starts February 2015, Wanaka, NZ. For more information contact 0800 TPP INFO or visit tpp.ac.nz/skipatrol

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

62

case study - walking the line // ryan leong Ryan Leong is the snow safety officer at Whakapapa ski patrol and a regular North Island contributor to the crystal ball. Here he shares the details leading to a close call whist doing avalanche control work at Whakapapa along with the reminder to “walk the line”(Johnny Cash).

On August 16th while carrying out avalanche control work I triggered a size 2.5 windslab. A few lemons lined up which turned it into a near miss. The moment it happened, or almost happened, I was immediately aware of the holes in my decision making and the shortcuts I had taken. We have since carried out an in house investigation to capture the learning, and systems have been formally updated and implemented to minimise the chance of this happening again. Below is my account of how it all panned out, and hopefully it gets some other folk out there re-thinking about these things so we can all stay a little safer.

The Lead Up My day began with an early start (3:00am) as we were coming into the tail end of week of snow and wind and the masses would be frothing at having a sunny Saturday after a good storm. It had stopped snowing late on the previous day just as the wind increased to gale – extreme South Westerly. Due to the wind strength it was not possible to use the usual snowmobile transport up to our upper mountain base so myself and Nick (patrol supervisor) were picked up by a groomer. We drove around the ski area blading-out test slopes to try and get some idea of what was happening in the snow, what the avalanche hazard was, and how things had changed from the previous days observations. Driving around in the groomer showed a weakness around 60-80cm down which appeared clean and planar (SP) but did not show a very high propensity for propagation – while blading out wind loaded slopes you could see the planar shear, but the slab only cracked out at most a meter from the edge of the groomers blade). It would have been nice to get out on the snow with a shovel and have a good look, but the wind and blowing snow made this impossible.

For now, observations from inside the cab of a groomer was the best that we had to work with.

Once it became light enough to see the wind gradually eased to the point where we could safely move around on skis. Nick and I made up a few charges to test some of the more reliable indicator slopes so that I could start gathering some better information on what sort of problem we were dealing with. We shot 3 paths from 2000m down to 1600m, and only got one very shallow size 1 slab. So far no sign of any activity on the deeper weak layer. Most avalanche paths on the East side of the ski area had been controlled the day before with mainly size 1 results, but overnight these paths had all reloaded with significant amounts of wind transported snow, and the strength of the wind had stiffened up the slab notably (ranging from1F to P hardness). Because of this I decided to continue on with control work despite getting no results from what were generally pretty reliable indicator slopes. We started a control route on the upper mountain and shot another regular performer which has a reputation for surprising us, and has taken more than a few patrollers for a ride over the years. No result. No cracking. Just a crater. This path loads very rapidly from the SW and often gets two to three times as much wind loading compared to similar start zones. I probed through just over 3m of new stiff wind slab down to the old snow surface. The slab was very consistent until you hit a thin density inversion just above the old/new interface. I had just tested this slope with explosives, and skied over it so I felt confident that a skier would not be able to trigger this layer. However, seeing how much wind loading there was only confirmed that I wanted to keep the control work going. It was a low likelihood, but high consequence situation.

Control work continued with mostly no results, however two paths produced size 2 results which ran at the weakness just above the old / new interface and in the process cleaned out all of the new snow which CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

63

case study - walking the line conT’D // ryan leong had accumulated over the previous six days since the storm had started. This once again confirmed that despite having a slab which was largely unreactive to large loads we should continue with control work, but refine the plan to target the steeper start zones which had less support and were directly lee to the SW, as this seemed to be the common thread of the paths that had ran so far. We had shot other paths which fit into this category, and they didn’t move at all, so I knew I was still a long way off figuring it out for the day. It’s a hard call to say that you can trigger things with a bomb, but not with the weight of a skier. Spatial variability is a terrifying thing so the safe bet was to stick with the plan.

I had noticed the loading on the Lower Amphitheatre start zone while on a control route earlier in the morning, and had put this on the list as a path which would need controlling before opening that terrain to the public. It had been a busy morning for the team getting terrain open, doing control work, and also having a few ski area accidents to deal with. Being aware that our resources were already pretty stretched I made the decision to have a patroller stand guard at the closure to prevent anyone from accessing the run-out, and I would then ski over and control the Lower Amphitheatre start zone on my own. My thinking about going solo was that I could access the path safely without crossing any avalanche terrain.

After looking at the path from above I decided on placing a shot mid path. From what I had seen earlier in the day I was not convinced that I would get a result. It felt like I was just doing it because I had told myself I would, rather than because I thought it might actually go from public skiing on it, let alone with explosives. Due diligence.

Photo: Ryan under the Amhitheatre crown wall

The Event I skied over to just above the start zone and viewed it from above the true right. At the time the path had a clearly defined start zone (an abrupt angle change from around 10 degrees to around 40-45 degrees).

I prepared my charge approximately 3 meters back and onto the flats from the edge of the start zone. I jammed my ski poles into the snow and tied off the cord which was tied onto the shot and threw it onto the path. I side stepped back up hill approximately another 5 meters and waited for a detonation. The shot went off and a large crown wall fractured about 4 meters in front of me – between me and where my ski poles / rope reel was. My poles and the tied off rope reel then tumbled off down the slope along with the rest of the debris. This is the largest this path has gone in our recorded history. The crown wall was around 3.5m at its tallest (directly below where I was situated) and tapered off to 40cm. It went 40m wide, and ran around 200m to the bottom of the path filling up a large benched area about half way down, then continuing on into the bottom of the Amphitheatre.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

64

case study - walking the line conT’D // ryan leong What caught me by surprise This went much larger, and broke back much further than I was anticipating. When I had thrown the shot, I thought I was in a safe location, but just to be sure I stepped back up another 5 or so meters. As it turns out, where I threw the shot from was still down slope from where the fracture appeared. Had I not taken the extra precaution of moving further back up hill from where I initially felt would be safe, I would have been taken for a serious ride with very serious consequences. This was probably the first time in my memory that I have had solid, positive confirmation from using an extra layer of defence. How often do we put extra measures in place, and never know if they actually were necessary? The fact that this one actually came into play gave me a good shake up. It left me a little rattled from how close this was to being an actual involvement as opposed to a near miss.

Why did it go so big The Lower amphitheatre path had a seemingly well defined start zone as mentioned above, but in hindsight this was clearly not the case. Prior to the storm the start zone had more of a slow convex roll at the top, and the current shape was the result of the wind loading from the week prior. This is why it pulled back so far from where I thought was a safe spot. Additionally, this terrain had not been open over the last week due to the weather so had not seen any active control over the storm.

As to why it went so much larger than many other paths that day, I can’t pin it down to any significant factors. We had shot multiple start zones with similar characteristics and got no results. The only other similar result was from a path known as Three Boys Bowl, which is located outside of the western boundary of the ski area. It is a similar feature, and went naturally at size 3 sometime in the preceding 24 hrs. This was only observed the following day once the weather cleared further, and was the only observed avalanche from the backcountry throughout the entire storm cycle.

Photo: Substantial Amhitheatre crown wall

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

65

Photo: Unmistakably Tongariro with debris from the Amhitheatre slab in foreground

case study - walking the line conT’D // ryan leong Personal contributing factors Fatigue – Having Mike (snow safety assistant) on light duties due to injury meant that my work load had increased significantly. The last few weeks had been 6-7 days per week with long days. Add a very early start time to the day on top of that.

Pressure – On days like this there is obviously going to be operational pressure to complete avalanche control work as quickly as possibly, plus there was the pressure to maintain as many patrol numbers for set up and accidents. This was not imposed on me by ski patrol or ski area management, but more self imposed. I wanted to be as efficient as possible and not tie up any more resources than necessary. We were light on the ground as it was.

Things that worked in my favour After throwing the shot and tying it off I decided to move back further than I thought was necessary. I was aware that I was tired, and adjusted the distance I would normally consider safe accordingly to give me an extra safety buffer to account for this.

Things I would change for next time..

Working alone. This one is painfully obvious. The concept of working in pairs while doing control work is standard practice at Whakapapa but it is amazing how you start making exceptions, justifying them to yourself, and all of a sudden you are doing something a little more often than you should…My plan was to avoid all avalanche terrain, and although this was totally possible in this zone, the reality is that I did cross the top of the start zone – even if I didn’t think I did… How else would my poles have gone for a ride? Plans can change while on a control route, and having a control route assistant allows more flexibility to do so safely. It also gives another set of eyes and a different perspective to bounce decisions off. Had the slab broke another 4 meters uphill I would have gone for a serious ride, and with no one spotting me. Although Mike was coordinating the control teams movements he would not have known about it for a good few minutes until I failed to call in the result over the radio.

This was a good solid wake up call for me and my line on the confidence over time graph has taken another solid hit. I’m glad I have managed to have this experience and take the learning from it without copping the full brunt of an involvement- and there has been plenty of good learning from it. Hopefully it prompts a few other people to reassess their decisions and safety systems while working or recreating in avalanche terrain. I’m sure most people reading this will be doing an awesome job of keeping them selves in line, but its always good to keep checking in on yourself. It’s something I will definitely be doing regularly.

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

66

PARTING PICs

Above: Treble Cone / Gulmarg (India) Exchange Ski Patroller Anwar Sheikh pauses during a control route prior to openning the Saddle Chair, August 2014 . Photo - G.Smith Below: The race is on! Avalanche rescue team digging exercise during the ‘Remarkables Ice & Mixed Climbing Festival. Photo - G.Smith

NEXT ISSUE OF

CRYSTAL BALL

DUE: 24 June 2015

Submissions deadline due:

20 MAY 2015

CRYSTAL CRYSTAL BALL BALL | | Periodical of the New Zealand Avalanche Community

67