NZAD June 2022

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JUNE 2022

feedback Matt Jeffrey

Steve Schreiber nzad interview

Snow from space Todd Redpath

DAN KELLY Proud Partners


Kia Ora Everyone!

Cover Shot A size 4.5 slab avalanche engulfs the Raspberry avalanche path on Mt. Belle in Fiordland National Park. The avalanche was triggered with explosives by the Milford Road Alliance avalanche safety team.

We hope that you have all had a great Aotearoa summer and that winter has been treating you well. For most of the country winter has arrived with a bang after an Antarctic outbreak dumped metres of snow, even to low elevations. This may be the best start a lot of ski areas and guiding operations have had in years! Hopefully there will be a lot more snow to come. This is the third season of the New Zealand Avalanche Dispatch. Each season we strive to improve our content and this issue is no exception. Because the NZAD is a digitally based publication we have been adding a lot of new digital links. We are aiming to give the reader a huge array of potential offsite resources just a mouse click away. Every advertisement is clickable and will lead you to the product or company it represents. Throughtout most of our other content you will find many other such excursions available. We plan to add many more of these digital resources in the future so click away and explore! Matt Jeffrey leads off the June 2022 issue by describing the difficult circumstances that a lot of ski fields faced last season. Tom Harris gives us an update on the NZ Mountain Safety Council. The Otago University Mountain Research Centre fills us in on some of their fascinating research projects. Ben Noll from NIWA gives us the climate forecast for our upcoming winter.Our NZAD News section is full of fun facts and updates and our new Click It! section is where you can find cool links to podcasts, books, videos and websites. Our new Double-Shot section features a Fiordland crust-facet combo close-up which is followed by Gary Kuehn and Ian Snape and a discussion about stress and resilience that is sure to change your persepctive on both. Next up is our ever popular NZAD Interview section featuring Steve Schreiber. What a career Steve has had! After that Don Sharaf's article on crust-facet combos should get you thinking about the snowpack to be and maybe some snowpacks that have already been. Our Featured Forecaster in this issue is Dave McKinley from the Mt Cook forecast region. We then feature a study conceived and conducted by Mark Sedon about tap test force measurement. Ryan Leong retuns to the Dispatch with a treatise on storm slabs and wind slabs. Ivar Finvers and Doug Latimer take a fascinating look at avalanche transceivers and interference, a must read for everyone. After that we have our Alpine Artist section featuring sculptor and skier Dan Kelly. Todd Redpath explains the newest satellite technology available for remote sensing of Aotearoa's snowpack. Following that, we have our new Historic Case Studies (haven't thought of a cool name for it yet!) section featuring a tragic avalanche accident at Arthur's Pass way back in 1933. We'd like to say a big thanks to the New Zealand Alpine Club and the Arthur's Pass Department of Conservation team for their help with that article. Finally, Ed Anderson rounds out the June issue with his rant about professionalism in his Hangfire column. Our Parting Shot, on the back cover features haiku by Colton Greenborough. Throughout this issue you will see prompts to send us your feedback. This is your chance to speak up and contribute to your avalanche community. We want to hear from you! Our next issue will be out in September. If you would like to send along any content or ideas for that issue please do so. We are always looking for ideas from our readers. We are also revamping our website currently. We hope to use this site as a "spillover" spot for additional news, stories, photos and other things and stuff so watch this space! Have a safe and productive 2022 winter season. See you in September!

Click the photo at left for the full video on YouTube. Photo Courtesy: Kevin Thompson Milford Road Alliance.

Contributors Ryan Leong, Matt Jeffrey, Steve Schreiber, Don Sharaf, Gary Kuehn, Todd Redpath, Peter Bilous, Mark Sedon, Ben Noll, Tom Harris, Ivars Finvers, Doug Latimer, Dave Mckinley, Dan Kelly, Edward Anderson, Rolf Schonfeld, Colton Greenborough

Supporters Mammut, Further Faster, MND/Ski Industries, Mountain Hut, Propagation Labs, Outfitters, Sportive, Southern Approach, Dopplemayr, Ginsberger. The NZAD operates as a non-profit, volunteer, community organisation. All of our support helps us to cover production, storage and distribution costs. To support the NZAD:

Submissions The New Zealand Avalanche DIspatch is published twice per austral winter season. We accept all written or photographic submissions relating to snow, avalanches, health and safety and just about anything else. To submit an idea please email us at:

Deadlines Our deadlines for submissions are as follows: June Issues: 1st of May. September Issues: 1st of August.

Contact Email: Media: Click any of the icons at lower left. Follow Rosko: @roskotheavalanchedog

Team Each issue of the NZAD is created by our generous contributiors and by Brad Carpenter and Caitlin Hall, with moral support from Rosko the Avalanche Dog.

No part of this publication may be reproduced without prior permission from the publisher. Opinions expressed in this publication are not necessarily those of the publisher or the editor. Every effort is made to ensure the accuracy of information in this publication, however the publisher assumes no responsibility for errors, omissions or consequences in reliance on this publication.


In this Issue Features





Covid Storm

Resilience and Stress

Tap Testing

Crusts and Facets

Some big operational avalanche decision making in the time of Covid and beyond.

It's all in your mind. An introduction on how to understand stress and how to be more resilient.

Hit me baby one more time! Attempting to quantify the tap test.

Shit sandwich anyone? Some thoughts on the interplay between crusts and facets.


66 89


71 82

WInd Slab or Storm Slab?

Avalanche Peak Accident

Transceiver Interference

All we are is dust in the wind...does New Zealand really have storm slabs?

An intriguing avalanche accident case study from 1933 and the learnings that came from it.

Blame it on the rain...or the power drill in your hand. New research into what interferes the most with our avalanche transceivers.


Snow from Space Like Star Wars only different. Some amazing imaging tools are available that could change avalanche forecasting as we know it.


Photo Essay


Featured Alpine Artist

48 92


On becoming a professional.

Steve Schreiber



The NZAD Interview.

46 37

NZAD Recommendations


Avalanche photos from the 2021 season.

Dan Kelly sculptor, skier and entrepeneur.

A kinetic powerplant just a kilometer from the sea.


NIWA updates, new hires, ARM 6 grads and more!

Our personal avalanche media choices.

Mountain Research Centre Some cool projects from the University folks.

89 "Now up until this point I had never heard Steve swear but on the radio all I could hear was the F-word over and over again as he was completely underneath the massive slide."



NZAD JUNE 2022 creation inspired by:

cassels BREWING triple cream milk stout

grateful dead playing in the band

THRASHER Skate Magazine


Feature Contributors

Mark Sedon was a ski patroller for 18 winters, and has been an IFMGA climbing and ski guide for the past 20 years. Recently he has specialized in ski guiding in Antarctica, Kashmir (India), Norway, and New Zealand. He started teaching Avalanche Stage 1 and 2 courses in 1996, is an NZMGA ski guide examiner, and the past chief guide for Harris Mountains Heli-ski.

When not skiing or sailing, Dr Ian Snape is CEO of Frontline MInd, a global training organisation based in Hobart that specialises in resilience, recovery and leadership. Ian is a former research leader and executive at the Australian Antarctic Division. He has led teams on 14 polar expeditions from the young age of 23. A fan of the Harry Potter books, Ian is the real life Professor Snape, previously holding Professorships at The University of Melbourne and Macquarie University. He is the author of more than 100 scientific papers and has recently published a practical handbook: Resilience by Design: How to survive and thrive in a complex and turbulent world (Wiley).


Matt Jeffrey is currently enrolled in the ARM 6 program, and has previously patrolled around New Zealand and Canada before qualifying as a paramedic. When not in the mountains Matt enjoys time on the coast, and is passionate about improving mountain medical capabilities in New Zealand.

Gary Kuehn seeks out snowy mountain environments throughout the world and for 20 years traveled between winters in New Zealand and destinations in the northern hemisphere, until Covid. As a former engineer studying ice mechanics he has transitioned easily into the study and pursuit of lower density forms while heli-skiing, skitouring, ski-mountaineering or sledding. He is an IFMGA guide, avalanche forecaster, and is an Instructor with Otago Polytec and The American Avalanche Institute. He is passionate about learning and facilitating human performance.

Doug Latimer started working in the avalanche industry in 1992 and has been guiding professionally for over twenty years. He has been very active with public avalanche education and training for over fifteen years. Doug is currently the lead guide for the Alpine Club of Canada. He is the author of the first interactive multi-media Ebook for public avalanche safety, Avalanche! the Guide’s Guide. https://www.shadowlightproducti

Ivars Finvers received his BSc and MSc in Electrical Engineering from the University of Alberta in 1985 and 1988 respectively. He obtained a PhD in Electrical Engineering from the University of Calgary in 1995. He has worked both in academia and industry. He was an Assistant Professor with the Department of Electrical Engineering at the University of Calgary, from 1997 to 2000, was well as a researcher working on medical instrumentation from 2004 to 2007. The rest of the time, he has been doing analog integrated design at various companies. Currently he is a Principle Engineer at Semtech, working on integrated circuits for high-speed optical communications links.

Ryan Leong has spent most of his career working on ski patrol at Whakapapa Ski Area on Mt Ruapehu where he runs the snow safety program. Ryan has also intermittently been the MSC forecaster for the Tongariro Region. Alongside skiing, Ryan also enjoys climbing, mountain biking, surfing and parenting- all at a very mediocre level.

Todd Redpath is a Lecturer in the Schools of Geography and Surveying at the University of Otago. He teaches in the areas of climatology and remote sensing (satellite and aerial mapping) and his main research focus is seasonal snow in the Southern Alps/Kā Tiritiri o te Moana. Outside work he spends as much time outdoors as he can, especially snowboarding and splitboarding in the winter. He is particularly keen on getting good turns within two hours drive of Dunedin and has a 33% success rate on the Rock and Pillar Range.

Don Sharaf has traded hats within the avalanche industry. Following two professional level avalanche courses in Canada this fall, he has taken a deep dive into work for Dave Hamre and Associates. In his free time he continues with his welding commitments and SAR callouts. His wife says he is still making poor decisions in the time management realm.





In this essay we've got a slew of avalanches from the New Zealand Mountaind Safety Council Information Exchange (Info-Ex). The Info-Ex is critical for avalanche safety in New Zealand. We'd like to thank all of the ski area and guiding businesses and the Mountain Safety Council for letting us share these photos with our readers.

Monk Glacier, Liebig Range. 11th September 2021. A snowboarder triggered a 20 cm deep storm slab lookers left and it stepped down to 80 cm deep graupel layer to the centre of the slope. He was the 18th person on this slope. Another member of the group got fully buried (20cm deep from the surface) but was rescued by other members within two minutes.



Cleft Peak East September 23 2021 This naturally triggered size 4 persistent slab failed facets that formed eleven days earlier. The avalanche occurred on a a southeast aspect at 2150 m. The crownline was 300 m wide, 250 cm thick, and 600 m long.


Hamilton Peak, Craigieburn Range, 13th August 2021. This size 2 slab avalanche was triggered remotely by a ski patroller on approach and was the first avalanche reduction mission on upper Hamilton for the 2021 season. The average crown height was 45 cm. The slide ran to mid path around 550 meterslong and the debris deposition ran into a gully with sections over 1.5 m deep. We had two similar slides go remotely as we approached wind loaded zones the next day on similar aspects. Overall ski quality that day: 7.5 out of 10. Photo Courtesy of Hans Hjelde.



The Perch, 3rd of August 2021 A snowboarder accidentally triggered this size 1.5 storm slab. This occurred on a 40 degree slope on a southwest aspect at 2350 m. The slab failed on decomposing fragments and was 10 m wide, 20 cm thick, and 100 m long.



Galactic Bypass, 11 September 2021. This picture perfect size 1 wind slab was triggered by a skier on a north aspect. The slab failed on a melt-freeze crust that formed a week prior and was 30 m wide, 10 cm thick and 50 m long.


Valley Headwall Left, Mt Tongariro. This size 2.5 wind slab failed on an older melt-freeze crust within rain saturated melt forms. The avalanche occurred on a northeast aspect at 2380 m and was triggered remotely by a 3 kg powergel explosive charge. The crownline was 100 m wide, 70 cm thick, 100 m long.


Done Thing, 22nd September 2021 This size 2 persistent slab failed on near surface facets at 1850 m on a 36 degree slope on a southeast aspect. This avalanche was triggered by a snowboarder and was 5 m wide, 30 cm deep, 250 m long.


Alaska 1 British Columbia 5

State or Province

Washington 1


Colorado 7

Idaho 2 Wyoming 2

Montana 4

Mountaineering 4 Skier 7


Danger Rating

4 2

Activity E








0 LO W

Avalanche Fatalities 2021-2022 24

North America

Snowmobile 8

South America Argentina 1



(All mountaineering)

Ecuador 6 Courtesy Avyboy Industries. All data current as of 31 May 2022 derived from thorough internet searches. Not all fatalities may be noted here.

Snowboarder 2


Switzerland 14

Austria 17

Mountaineering 4

Spain 2 Slovakia 3

Activity Skier 29


Nationality France 9

Poland 2 Norway 5

Germany 3

Italy 8

30 20

Danger Rating
























Asia Roadway 4

Residential 2 Military 11

Industry 5

Recreation 3


50 Kazakhistan 2

Turkey 3

Nepal 1

India 7

Kyrghistan 4 Emigrant 19

Japan 1

Pakistan 4


Afghanistan 22

25 Courtesy Avyboy Industries. All data current as of 31 May 2022 derived from thorough internet searches. Not all fatalities may be noted here.

1994, Bluff Face Size 4 deep slab avalanche triggered with explosives during active helicopter mitigation efforts. The deep slab failed on large grained facets near the ground. Debris overran the base area, car park and carried on into the snow-making pond. Photo Courtesy of Porters Alpine Resort.


Low Confidence and High Uncertainty in Covid Times By Matt Jeffrey

The past couple of winters have included an extra level of staffing uncertainty for avalanche forecasting operations in New Zealand. There was an anxious start to winter 2021 around the Craigieburn range as ski area operators struggled to fill snow safety positions without the usual help of our international friends who were unable to enter New Zealand due to Covid travel restrictions. This led to new management methodology as well as increased responsibility on developing forecasters, a perfect recipe for uncertainty. To adapt to the shortage of available snow safety staff, Porters developed a model that encouraged enthusiastic team members looking to complete their ARM level 6 to undertake a significant amount of the forecasting and planning. This was overseen and mentored by some industry stalwarts that we were fortunate to have on our team. This mentor, mentee relationship was critical as we worked through the winter, aiming to promote optimal growth conditions for employees, manage stress levels, and deliver a safe and effective snow safety program. As a developing snow safety professional, I often struggle with uncertainty when forecasting for our ski area, and find it is frequently a cause of anxiety for myself and others in the industry. When faced with large amounts of uncertainty, research shows that we are likely to seek feedback in order to find answers 1. Unfortunately, avalanches are the feedback and have a cruel way of giving it, consequently if our perceived risk doesn’t match the actual risk, we are rolling the dice with our decisions. Fortunately, ski patrols have the capacity to safely test our hypotheses and forecasts with dynamic control measures, ski cuts and explosive avalanche control (alleviating some uncertainty), however, other mountain professionals and backcountry recreationalists aren’t as fortunate. The following case study occurred during the crux of our winter, when we were unable to use our dependable explosives to test the validity of our forecast and reduce uncertainty. The Covid Storm In mid-August the last of a series of three active Northerly fronts delivered the storm of the winter. As it approached, I received a call from our operations manager whilst on a weekend away, resulting in a rush to make it back before the almost certain closure of Porters Pass road access. On the 17th of August the precipitation gauge recorded 75mm in 24 hours. This initially fell as rain to ridgetop before rapid cooling resulted in cold snow down to SH73. We estimated 50cm of new snow on the upper mountain, which was accompanied by gale north westerlies. As a rough guide, based on avalanche paths and infrastructure location, our snow safety team starts thinking about threats to infrastructure after around 30cm of new snow.



The afternoon forecast on the 17th of August expected likely storm slabs up to size 3.5 on SE aspects, with Bluff Face (see photo, circa 1994) our main concern. Additionally, there was a possible chance of large avalanches stepping down into an old persistent slab problem in this zone. With a further 20mm forecast for the following morning, accompanied by clearing skies and Moderate N / NW winds, we knew a significant challenge lay ahead as the following day looked to be one of the biggest days of the season - if the instabilities could be managed.

Clearing skies over Porters on the 18th of August. Bluff Face is on lookers right.

Our avalanche forecast had resulted in operational restrictions above the access road since the morning of the 17th. This is due to the Bluff Face runout zone threatening the base area. Therefore, with helicopter our only form of access the following options were considered: An inspection flight to gather data and possibly use explosives on representative test slopes. Explosive control of Bluff Face with the expectation that a result could damage infrastructure. Keep access to the ski field closed due to avalanche hazard and wait for the snow to settle enough for control work. As we were discussing our options, news came through of the Covid lockdown. A nightmare in itself, but it at least relieved the operational pressure of potentially being closed on the best days of the season. The following morning we were greeted with blue skies and moderate winds. Investigative


drone piloting revealed natural size 3 avalanches from neighbouring indicator slopes - The Weather Book (2000m, SE aspect) and Carn Brea (2000m S aspect), as well as a size 2 inbound avalanche in Pot Belly (SE 2000m). These slopes are representative of Bluff Face and I kept questioning, “Why didn’t Bluff Face run during the storm, and would it be reactive to explosive control?” These are questions we thankfully didn’t have to answer, and the outcomes we’ll never know, unfortunately limiting the validity of the experience for future learning. Due to the lockdown the disappointment around the Southern Alps was apparent, with cries of missing the best storm of the last 5 years echoed throughout. I’m sure many of us were sitting at home thinking about what could’ve been from that great storm, however, there’s a lot of questions left unanswered, and they all aren’t just about the ski quality. A part of me knows that lockdown saved a difficult decision for our mountain, as in reality there was no likelihood of opening on the 18th and we faced the unnerving decision of how long to wait until accessing and controlling the terrain. This event highlighted to me the amount of uncertainty in our line of work. Covid times have increased uncertainty around the world, and it is now something that people are forced to deal with in their daily lives. As avalanche professionals and recreationalists, uncertainty is also something that we must accept, and develop our own methods for assessing the validity of our decisions. Due to the lack of definitive feedback our decisions are made without the expectation of learning whether it was right or not. How many slopes have you skied that were kind enough to not alert you of a bad decision? Covid times have increased uncertainty around the world, and it is now something that people are forced to deal with in their daily lives. As avalanche professionals and recreationalists, uncertainty is also something that we must accept, and develop our own methods for assessing the validity of our decisions. Due to the lack of definitive feedback our decisions are made without the expectation of learning whether it was right or not. How many slopes have you skied that were kind enough to not alert you of a bad decision? Techniques for Reducing Uncertainty I’d like to finish this article with some suggestions on how to manage your own uncertainty and hopefully enjoy some great turns this winter. Please feel free to get in contact and to provide some feedback. Seeking Feedback By seeking feedback we are more equipped to assess our capabilities, adjust goals, develop new skills, and improve performances (1). Often the biggest barrier to this is our egos, as constructive feedback takes maturity to accept. This is supported by the fact that when considering seeking feedback people balance their desire for feedback against the costs associated with criticism, and often only ask when the need exceeds their potential loss of status (2, 3). Examples of this could be novice patrollers refraining from asking what could be thought of as a dumb question, or an experienced forecaster who is resistant to being challenged. Awareness of these barriers is the first step to overcoming them, and I encourage you to take this into your organisation by adopting reflective practice even when things go according to plan. This is


helpful towards removing the assumption that we are debriefing because something went wrong, leading to defensive barriers and less effective reflection (4). Increasing Your Safety Margin Your margin of safety is “taking additional caution due to uncertainty that lies beyond the expected avalanche hazard or risk (5).” For example, if our confidence is less than good in our daily hazard forecast, we have admitted uncertainty and therefore should increase our caution. The confidence levels of poor, fair, and good, inversely relate to safety margins of low, moderate, and high. A technique worth trying this winter is specifically identifying how we intend to increase the safety margin. This could be described as; taking an extra shot on control routes, implementing travel restrictions, or waiting a little longer for the snow to settle. When uncertainty is high, the most effective method can be elimination, by simply avoiding that slope or closing that terrain. It takes courage to stop and say, “I don’t know,” much more than skiing that rad line. Targeting Information The stimulus for seeking more information is acknowledging that there is uncertainty. Instead of relying on the information we have, and what we do know about the current conditions, Dale Atkins urges us to consider what we don’t know, before looking for answers (6). However, increasing the information available to us can be overwhelming or unproductive if it only confirms your hypothesis, or is sought with a bias towards an end goal (6). An example is increasing confidence through multiple CTN results when we are uncertain about a deep instability. Therefore, it is important to seek the right information, which means targeting our observations to reduce what we are uncertain about. You may be familiar with the “field information to target” column on some hazard evaluation forms, which is not to be missed. Specific to this case study, due to my limited historical knowledge of the mountain I found a useful resource was reaching out to previous forecasters to learn about previous similar scenarios and management strategies. By targeting what I didn’t know about the mountain, I was able to increase my decisionmaking capacity. References 1. Anseel F, Lievens F. The Relationship Between Uncertainty and Desire for Feedback: A Test of Competing Hypotheses1. Journal of Applied Social Psychology. 2007;37:1007-40. 2. Ashford SJ, Cummings LL. Proactive feedback seeking: The instrumental use of the information environment. Journal of Occupational Psychology. 1985;58(1):67-79. 3. VandeWalle D, Cummings LL. A test of the influence of goal orientation on the feedback-seeking process. Journal of Applied Psychology. 1997;82(3):390-400. 4. Seelandt JC, Walker K, Kolbe M. “A debriefer must be neutral” and other debriefing myths: a systemic inquiry-based qualitative study of taken-forgranted beliefs about clinical post-event debriefing. Advances in Simulation. 2021;6(1):7. 5. Campbell C, Conger S, Gould B, Haegeli P, Jamieson B, Statham G. Technical Aspects of Snow Avalanche Risk Management2016. 6. Atkins D. Risk: Sometimes we are focusing on the wrong action. The Avalanche Review. 2013:22-3.


Mountain Safety Council Winter Update By Tom Harris NZMSC Alpine Partnerships Advisor

Hello readers, Like you all I’m really looking forward to this winter. Not only does it look like a lot of things will be creeping closer to normal, but we at MSC have been hard at work on a number of projects that are about to take shape. It should be an exciting year! Read on for the details. Wishing everyone a great winter ahead, and for plenty of snow to entice tourists over the open border! Happy reading and as always, if you want to have a chat, just get in touch.

Updated MSC Course Material MSC has conducted a regular review and update of our education resources for avalanche course providers, as we typically do every few years. The most obvious change that we have made is to change the names of the MSC course material. Avalanche Awareness will now be known as Avalanche Skills Course 1 (ASC1) Backcountry Avalanche will now be known as Avalanche Skills Course 2 (ASC2)

Aside from the name changes, this work aimed to: Bring the terminology and imagery in the resources up to date based on changes to industry standards and changes made to Review existing PowerPoints, instructor resources, and student workbooks. From there, update and adjust for consistency and ease of use. Incorporate a component to the ASC2 course material around the concept of “Strategic Mindset”. We’d like to thank Hugh Barnard raising this idea in his talk at SHAC last year. You can watch that presentation here. Since MSC’s Research ‘Avalanche Culture within the NZ Mountaineering Community’ is not yet complete (more on that shortly), we have not yet assessed options around incorporating additional content for climbers into the course material. However, we are still planning for this to take place in time. The course packs for participants have changed names reflecting if they are for ASC1 or ASC2. However, apart from new certificates, there are no other changes to the packs. The Assessor/Rescue card, Transceiver Certificate, and (for ASC2) Avalanche Awareness in NZ Backcountry book are all unchanged. Of note is the price for these packs which has not changed for 2022. If for some reason a provider has stock of the old course name certificates, they should get in touch and we can sort out swapping them for the new ones. Avalanche course providers that have an existing agreement with MSC have been contacted and supplied access to the new digital material and instructions on ordering course packs for participants. If you’d like to become a provider of MSC Avalanche course material and the ASC1 and ASC2 courses, please get in touch.

Pilot Aspiring NZAA Forecast Region This change should make it more obvious to the public that there is a progression with these courses, and to make it clear which one they are on. We have had a lot of feedback suggesting many participants haven’t understood the difference between Avalanche Awareness and Backcountry Avalanche courses until attending, so hopefully this will clear things up. It should also, in time, make it easier to indicate to overseas parties what level participants have trained at. Hopefully it also raises interest in continued learning in the form of attending the second, ASC2 course! This name transition will take time, and MSC doesn’t expect all providers will switch over to this new naming convention immediately, as course/trip names will likely still contain references or perhaps even be known fully by the old names. That is ok, as the old and new names reflect the same courses. But to give it a kick start, all the updated MSC course material will now use the new names (and associated logos) as will certificates provided to participants. We will also be sharing this change through our channels to assist.

This might be the most exciting news for this winter. For 2022, MSC will be running a pilot 13th forecasting region for the NZ Avalanche Advisory. This new region will be called ‘Aspiring’ and will comprise of the western portion of the old Wanaka region, as well as the area around Mt Brewster. For a better image of the changes to come, see the below map image. For reference, the upper red boundary is last year’s Wanaka region, and the lower red boundary is last year’s Queenstown region. The pink shading represents the new Queenstown region, the yellow the new Wanaka region and the green the new pilot Aspiring region. As mentioned, the only area that will be newly forecasted terrain is the Mt Brewster area (top right green area). Some notes on the change: The Wanaka and Queenstown region boundaries have changed as a result of the new pilot region. Most notably, the Wanaka region will no longer forecast for Mt Aspiring and areas along the divide. Our Wanaka forecaster can now focus on and cater to users in the popular Treble Cone Backcountry and Harris Mountains areas.


New Zealand, specifically targeting mountaineers and alpine climbers. The survey has gone out and was completed by almost 800 mountaineers across New Zealand. We consider this a great number considering how large the survey was. Many of you will know firsthand! A big thanks to those of you who contributed your time and experience to this research. We have initial findings already and are now in the process of breaking all of it down. Part of this will be a profiling exercise where we will show how the answers to certain questions differ based on profiles created using demographics and characteristics of the respondents. It's fair to say that there’s more information to digest from the survey results than we expected, so we will need a bit more time to build a suitable method for sharing, but we are on the task and look forward to sharing insights later this year.

Public Observations 2022 Our NZAA Public Observations competition will be back this winter. We are once again running the prize giving, and this will look similar to the past two years. Prizes are still being finalized but will me made public in the coming month leading into winter. To be eligible to win, public observations must be submitted WITH A PHOTO. For more info, check out . So, keep submitting public observations at this winter. Most importantly, submitting observations helps to inform your fellow backcountry users. The fact that you could win some awesome backcountry gear is just icing on the cake! As part of the change, the area around Mt Brewster (not previously forecasted for) will now be accounted for in the new Aspiring Region, appealing to the many users of the area. The scheduled forecast dates for the new Aspiring region will be July 1 – November 30th, 2022, but this may be extended or shortened if the conditions warrant. Make yourself familiar with the new region boundaries by checking them out on the map at Ultimately the main benefit of this change is that users heading to Mt Aspiring National Park and those heading backcountry near Treble Cone will not have to look at the same forecast. This means they will have information more relevant to where they are going, rather than having to dissect which information in the old Wanaka forecast was relevant to them. The new region boundaries will better represent areas of relatively uniform snowpack conditions, which will make forecasting easier too. It is important to note that this new region is a pilot project. After the 2022 season, MSC will review the project and should it be deemed a success, we’ll apply for long term funding for this additional region. However, it is not yet a permanent, long-term change. We certainly have high hopes for it though! At the time of writing, MSC is in the final stages of coming to an agreement with a forecasting partner for the new ‘Aspiring’ region.

Research: Avalanche Culture within the NZ Mountaineering Community MSC, along with Research NZ and with the support of the NZMGA, NZOIA and NZ Alpine Club, has completed the survey portion of a research project that seeks to develop a clear understanding relating to the ‘attitude and behaviour of the New Zealand mountaineering community towards avalanche dangers and avalanche safety’. This research, alongside statistical evidence, will be used to form the basis of improved avalanche prevention in


Av C ala 20 ou n 2 rs ch 2 e e Sc S he kill du s le

On tthese two pages we've compiled all of the NZ winter 2022 avalanche skills courses. Now all you have to do is find the type of course that you would like to take and the provider in the list and click on their link on the next page. How easy is that? Seems pretty easy...

JUNE Saturday 25 - Two Day Avalanche Awareness Course - Climbing Queenstown Saturday 25 - Four Day Alpine/Avalanche Course - OENZ Monday 27 - Four Day Alpine/Avalanche Course - OENZ

JULY Friday 1 - One Day Avalanche Awareness Course - Queesntown Mtn. Guides Saturday 2 - Four Day Backcountry Avalanche Training - OENZ Monday 4 - Four Day Backcountry Avalanche Course - Alpine Recreation Sunday 3 - Four Day Avalanche Training - Hillary Outdoors Monday 4 - Four Day Backcountry Avalanche Training - OENZ Friday 8 - Backcountry Travel Course - Queenstown Mtn. Guides Friday 8 - Two Day Avalanche Awareness Course - Climbing Queenstown Saturday 9 - 1.5 Day Avalanche Awareness Course - Alpine Guides Monday 11 - Four Day Backcountry Avalanche Training - OENZ Monday 11 - Two Day Avalanche Course - NZAC - Arthurs Pass Wednesday 13 - Two Day Avalanche Awareness Course - OENZ Friday 15 - One Day Avalanche Awareness Course - Queesntown Mtn. Guides Saturday 16 - Two Day Avalanche Awareness Course - Anna Keeling Guiding Saturday 16 - One Day Avalanche Awareness Course - Alpine Guides Saturday 16 - Two Day Avalanche Awareness Course - NZSSI Sunday 17 - Two Day Avalanche Course - NZAC Monday 18 - Four Day Backcountry Avalanche Course - Alpine Recreation Monday 18 - Seven Day ARM Level 5 Avalanche Course - Otago Polytech Thursday 21 - Four Day Alpine/Avalanche Course - OENZ Friday 22 - Backcountry Travel Course - Queenstown Mtn. Guides Saturday 23 - Two Day Avalanche Awareness Course - Climbing Queenstown Saturday 23 - Two Day Avalanche Awareness Course - Anna Keeling Guiding Saturday 23 - One Day Avalanche Awareness Course - Alpine Guides Saturday 23 - Two Day Avalanche Course - OENZ Saturday 23 - Two Day Avalanche Course - NZAC Monday 25 - Four Day Backcountry Avalanche Course - Adventure Consultants Wednesday 27 - Four Day Backountry Avalanche Course - Anna Keeling Guiding Thursday 28 - Two Day Avalanche Course - NZAC - Tukino Friday 29 - One Day Avalanche Awareness Course - Queesntown Mtn. Guides Saturday 30 - One Day Avalanche Awareness Course - Alpine Guides Saturday 30 - Two Day Avalanche Awareness Course - NZSSI



AUGUST Monday 1 - Four Day Backcountry Avalanche Course - Alpine Recreation Monday 1 - Four Day Backcountry Avalanche Course - Adventure Consultants Friday 5 - Four Day Backcountry Avalanche Course - Alpine Guides Friday 5 - Two Day Avalanche Awareness Course - Climbing Queenstown Friday 5 - Backcountry Travel Course - Queenstown Mtn. Guides Saturday 6 - Two Day Avalanche Awareness Course - Anna Keeling Guiding Monday 8 - One Day Avalanche Awareness - Hillary Outdoors Monday 8 - Four Day Backcountry Avalanche Course - NZSSI Wednesday 10 - Two Day Avalanche Awareness Course - NZSSI Thursday 11 - Four Day Alpine/Avalanche Course - OENZ Friday 12 - One Day Avalanche Awareness Course - Queesntown Mtn. Guides Saturday 13 - Two Day Avalanche Awareness Course - OENZ Monday 15 - Four Day Backcountry Avalanche Course - Alpine Recreation Friday 19 - Four Day Backcountry Avalanche Course - Alpine Guides Friday 19 - Backcountry Travel Course - Queenstown Mtn. Guides Saturday 20 - Two Day Avalanche Awareness Course - Climbing Queenstown Saturday 20 - Four Day Backountry Avalanche Course - Anna Keeling Guiding Monday 22 - Four Day Backcountry Avalanche Course - Adventure Consultants Monday 22 - One Day Avalanche Awareness - Hillary Outdoors Friday 26 - One Day Avalanche Awareness Course - Queesntown Mtn. Guides Saturday 27 - Four Day Alpine/Avalanche Course - OENZ Monday 29 - One Day Avalanche Awareness - Hillary Outdoors Monday 29 - Two Day Avalanche Awareness Course - OENZ Monday 29 - Four Day Backcountry Avalanche Course - NZSSI

Anna Keeling Guiding

SEPTEMBER Friday 2 - Backcountry Travel Course - Queenstown Mtn. Guides Monday 5 - Four Day Backcountry Avalanche Course - Alpine Recreation Monday 5 - Four Day Backcountry Avalanche Course - Adventure Consultants Thursday 8 - Four Day Alpine/Avalanche Course - OENZ Friday 9 - Four Day Backcountry Avalanche Course - Alpine Guides Saturday 10 - Two Day Avalanche Awareness Course - OENZ Monday 12 - Four Day Backcountry Avalanche Training - OENZ Monday 12 - Four Day Backcountry Avalanche Course - Alpine Recreation Monday 19 - Four Day Backcountry Avalanche Course - Alpine Recreation Tuesday 19 - Four Day Backcountry Avalanche Course - NZSSI Saturday 24 - Four Day Alpine/Avalanche Course - OENZ Monday 26 - Four Day Backcountry Avalanche Course - Alpine Recreation Monday 26 - Two Day Avalanche Awareness Course - OENZ



University of Otago Mountain Research Centre (MRC) Update Compiled by Todd Redpath The Mountain Research Centre (MRC) brings together researchers from the Schools of Surveying and Geography at the University of Otago who are focused on understanding environmental and climatic processes in Aotearoa’s alpine regions. Seasonal snow, avalanches and glaciers are specific focus areas for us. We specialise in using satellite observations to help improve our understanding of remote and vast environments, and maintain automatic weather stations at Brewster Glacier and the Pisa Range. Check out our website to learn more about the work we do and access data from our Pisa AWS as well regularly updated measurements of snow-covered area across the South Island:

Avalanche Hazards Research Hooker Valley We are using the Hooker Valley in Aoraki Mount Cook National Park as a natural lab for studying snow avalanche behaviour in a changing landscape. A range of sensors are helping us get a detailed view of the avalanche dynamics in the valley. Like many mountain ranges in Aotearoa, the snow is plentiful at high elevations in the Aroarokaehe Range on the west side of the Hooker Valley, with little or no snow persisting in the valley through the winter. Avalanches here consistently run well down into the valley with paths producing frequent avalanching. At the same time, avalanches are running through newly incised Figure 1 - Example avalanche cycle in the Hooker Valley from September 13, 2021. New avalanches occur in three paths over the a half hour period with debris visible from an earlier event in the Hayter Path (centre, across lake).


Figure 2 - Example avalanche from Hayter Path in Hooker Valley on October 13, 2021.

moraines left by the thinning and retreating Hooker Glacier, where they entrain rocks and dirt as they run into Hooker Lake. Add in the effects of predominant winds and the precipitation and temperature gradients extending east from the divide, and the terrain and climate setting is a good place to study avalanche behaviour. Last winter we deployed timelapse cameras to provide an under-the-cloud view of the avalanche paths that, along with satellite imagery, helps establish the frequency of avalanches in key paths like Hayter Stream and Stewart Stream. We will continue collecting data for the next 5+ years to establish a better record for how active the paths are. At the same time, this year we are going to deploy other sensors to try and measure the magnitude, or size of avalanches running into the valley. This work, in collaboration with GNS Science and the University of Canterbury will help us to calibrate avalanche models for estimating impacts from infrequent very large avalanches and better characterize the more frequent small avalanches. After one season of data collection, there are a few important observations we feel will help to improve forecasting and risk management in the future. First, we observed that during a few storm cycles, avalanches were running to the valley multiple times in the same path over a 24 or 48 hr period. This has implications for how we perceive of the changing hazard during and immediately after storm cycles. Second, freezing levels rising and lowering during storms often produced “winter” storm slab avalanches at high elevations but by the time the avalanche reached the lake the snow was flowing more like a wet “spring” avalanche. This transition in the flow regime is something we and our SLF collaborators in Switzerland are working on better understanding—and modelling—as a warming climate may make these events more common, including in regions with traditional continental snowpacks. In the 2021 season, we documented over 40 avalanches reaching Hooker Lake. In one avalanche cycle Hayter Stream Path had four avalanches reach the lake in one day. We are keen to see what the 2022 season brings!


Milford Road With collaborators at Milford Road Alliance, we have published work on modelling an avalanche in the McPherson path (Miller et al., 2022) that was discussed in the last issue of the NZAD. Combining topographic data from the MRA LiDAR scanning programme and our satellite imagery processing pipeline showed how important topographic representation in hazard modelling is when interpreting the results of any avalanche simulations. This work will underlie future modelling work in Fiordland and elsewhere in Aotearoa.

Matariki Project – Our Changing Landscape The Matariki Project, led by Pascal Sirguey and funded by an MBIE Endeavour Fund Smart Idea grant aims to transform environmental monitoring by automating high resolution satellite mapping of landscape change. This has obvious applications to natural hazards, and over summer the Matariki team (including Aubrey Miller and Simon Cox of GNS Science) put their rapid response mapping to the test. This included three-dimensional topographic mapping of the large rock avalanche on Mt Tasman in early February 2022 within days of the event, as well as analysis of a further rock avalanche onto the Hooker Glacier from Mt Beatrice that occurred during the same period, and the ongoing gully erosion of the Tasman Moraine at Husky Flat. Analysis of these satellite observations is continually improving our knowledge of the evolving hazardscape in the Southern Alps. You can view some visualisations of these analyses at

Modelling Snow and Catchment Processes Along with colleagues from Victoria University University of Wellington and NIWA, and funded by the Deep South National Science Challenge, we are undertaking work to improve the modelling of seasonal snow within the New Zealand Water Model (NZWaM). A major component of this work is using the image processing pipeline developed within the Matariki Project in order to map snow depth in the central Southern Alps from satellite imagery. Preliminary results are promising, and these maps provide an unprecedented level of detail when it comes to understanding the distribution (and re-distribution) of snow across our alpine environments. Historically, snow modelling work in New Zealand has assumed a linear relationship between snow depth and elevation – largely because we have had insufficient data to support any other approach. Satellite observations reveal that the reality is more complex than that, a fact that many NZAD readers will surely appreciate! Mapping snow depth in this way is the first step toward better representing complex seasonal snow processes within models, in turn paving the way to predicting the evolution of our seasonal snow under climate change with greater confidence.

References Miller, A., Sirguey, P., Morris, S., Bartelt, P., Cullen, N., Redpath, T., Thompson, K., and Bühler, Y.: The impact of terrain model source and resolution on snow avalanche modelling, Nat. Hazards Earth Syst. Sci. Discuss. [preprint],, in review, 2022.


Shawn Orloff Shawn Orloff, 44, died in Big Sky, MT on November 18, 2021. He was born in Miami, FL and grew up in Beverly, MA. He graduated high school from St. John’s Prep in Danvers, MA, attended Syracuse University in NY, and graduated college from the University of Montana in Missoula. Surviving family includes his mother, Sally Norris of Bozeman, MT; father, Michael Orloff of Dover, FL; wife, Noelle Orloff of Bozeman, MT; and several aunts, uncles, and cousins. He was employed by Big Sky Resort in Big Sky, MT. Shawn was a Massachusetts guy at heart. When he was young, he explored and skied the Northeast with family and friends, laying the groundwork for his future career. He spent time on the water with family and learned to sail, and his enthusiasm for being on the water would carry through his life. He often credited growing up near the ocean for his affinity for wild places and open spaces. Life on the east coast shaped him in other ways. He went on Grateful Dead tour and became a lifelong deadhead (to remember him, try listening to “Liberty” on repeat or any show from May 1977). One of his talents was baking. Shawn learned to bake an apple pie from memory when he worked at an apple orchard and through the years impressed many with his perfect pie crust. He qualified for and ran the Boston Marathon. He developed an interest in American history and politics, often saying, “if it wasn’t for Massachusetts, we’d still be a British colony.” And of course, he was a Red Sox fan. After moving to Montana and graduating college, Shawn went on to make skiing into his career. He was a ski patroller at Big Sky Ski Resort and Moonlight Basin for fourteen years. Skiing and working on Lone Mountain every day was a dream come true. He had the opportunity to work at other ski hills in his life; places like Treble Cone in Wanaka, New Zealand; Jackson Hole in Jackson, WY; Teton Pass in Choteau, MT; and Montana Snowbowl in Missoula. Skiing was more than a job for Shawn. He loved to ski, and he loved and found kinship in the culture and people in that world. Shawn made friends around the world in adventures near and far. Whether we skied with him once or hundreds of times, we have memories of laughter, adventure, and camaraderie. Shawn’s affinity for adventure and the outdoors extended beyond the ski hill. He worked on wildland fire crews like the Lolo Hot Shots and the Gallatin Rappel Crew, and he worked on several trail construction crews for the US Forest Service and Montana Conservation Corps. He was drawn to boats and fishing and being on the water and sharing those experiences with friends and family or heading out solo. Over the years he explored many places, but he would return again and again to his favorites like the Bob Marshall Wilderness, Yellowstone National Park, Missouri Breaks National Monument, and the Florida Everglades. There is so much more to say about Shawn and the life he lived and the impact he had on us - let’s keep telling his story to each other. We miss him. Right now, the landscape feels empty since he is gone from this world, but we know we will carry his memory with us for the rest of our lives.


NIWA Seeks Info-Ex Data Lawrence Kees

As a snow professional you may think that the information input into the InfoEx system is only used to aid your decisions on snow safety and operations at your field. Here at NIWA we are putting the InfoEx data to good use to help fill in the climate and snow monitoring gaps of our Snow and Ice Network. This is the first article describing what we are doing with the data contributed by snow professionals to the Mountain Safety Council administered InfoEx system. First off, thanks for your contributions to InfoEx and making it a great resource for understanding not just your vital operational decisions, but also New Zealand climate and hydrological processes. NIWA’s Snow and Ice Network (SIN) provides information on snowfall, depth of snowpack, snow melt and climate for ten alpine sites across New Zealand. It is funded as part of NIWA’s Climate Network and the National Freshwater Centre, the tool allows users (such as regional avalanche forecasters) to track snow conditions at sites further afield of the ski field network throughout the season. NIWA has been gathering data from these high-altitude weather stations for the last decade. As well as climate information, each of the 10 SIN sites (Figure 1) measure snow depth, while 6 sites additionally collect information on the total water content of the snowpack (frozen and liquid), otherwise known as snow water equivalent (SWE). This information allows us to see whether snow is tracking below or above normal for the time of year (Figure 2).

Figure 1; The location of the NIWA Snow and Ice Network. We are using InfoEx data to fill in the gaps of the network to improve the nations understanding on hydrological and climate process at altitude.

The SIN sites are located throughout the alpine regions of New Zealand and collect information on snowfall, snow storage and snow melt as well as alpine climate. Seasonal snow and ice dynamics affect alpine hazards, recreation, tourism, stream ecology, hydro-electric generation, and water abstraction and even building strength regulations. The SIN network data feeds into model simulations and remotely sensed images of snow, and is essential to understand, predict, and manage the snow resources and related hazards across New Zealand. Information from the SIN can also be used by rescue services to monitor hazards, organisations like DOC to help with their forecasting, as well as in research collaborations with universities. It goes without saying that New Zealand is a mountainous country. While our 10 SIN stations produce high quality observations, there is a lot of space between those stations. By bringing in data from the InfoEx database NIWA will improve the national understanding of what is happening with hydrology and climate. Ultimately this means that that everybody who inputs data into the InfoEx system will assist in improving the understanding of water and climate throughout New Zealand. Collectively the snow professionals of Aotearoa New Zealand have made a massive contribution through inputting your observations into InfoEx, thanks very much. We also have a big task of ensuring a high-quality data set that we can all rely on for our respective roles. For instance, the consistency of data input can be a bit variable. Weather observation location (lat. Long.) altitude, date and time are critical for all users to rely on the data for any use. We have extracted about 15000 individual weather observations across the north and South Island ski fields and heli-ski operations, a great resource. However, we can only use about 6000 of those observations because they are missing the location co-ordinates of the observation. The data gets a bit more difficult to interpret when the elevation field for the observations can vary up to 200m a.s.l for some locations with identical observation co-ordinates. This makes for some tricky interpretation of that data, not just for NIWA, but also for understanding what has gone on at your ski field.


Figure 2; An example of the freely available SIN information. Source

Maintaining a high standard of data input will not only greatly enhance your ability to manage your local avalanche risks. We will keep you informed throughout the season as we incorporate the InfoEx observations into the projects happening here at NIWA. We plan to show you examples of great datasets, some summary statistics of your data through time and some of the projects that improve the national hydrological and climatic knowledge. So, keep an eye out for the articles, and for each other. Here's to a great start to the season and we hope to see you out there! For more information about the Snow and Ice network, take a look at our website:

2021 NZ Avalanche Education Summary By Peter Bilous Otago Polytechnic Avalanche & Snowsport Programme Manager It was a very challenging year with lockdowns, re-scheduling courses, injuries, and staffing issues. We had similar numbers in both recreational courses and ARM Level 5 Pro and ARM Level 6 Pro numbers were again up by about 30%. Here are the numbers for 2021:

during the August/September lockdown period.

Of note for 2022 Due to high student interest on the North Island, for the first time Otago Polytechnic will soon be offering an Avalanche Risk Management Level 5 in late Sept 2022 at Whakapapa. Students will soon be able to apply at:

Professional Courses: ARM Level 5: 67 graduates with Otago Polytech (OP) x having 57 over 4 intakes and Tai Poutini Polytechnic having 10. -These have shown fairly similar totals over last two years. ARM Level 6: 12 x grads (OP) - up 30% each year over the last two years.

Recreational Courses: Avalanche Awareness Courses run: 44 Avalanche Awareness Course participants: 317 Backcountry Avalanche Courses run: 17 Backcountry Avalanche Course participants: 85 Both Awareness and Backcountry courses had similar numbers to 2020 which may be interpreted as greater student interest as numerous course providers reported having to cancel courses

New Zealand Certificate in Avalanche Risk Management (Level 5) - Otago Polytechnic Academic requirements: There are no academic entry requirements for this programme. Other requirements. You must be able to demonstrate evidence of basic ability to use avalanche transceivers, shovels, and probes through a document signed and dated by a graduate of this programme (or recognised equivalent programme at this level or higher) stating that you meet the following criteria: Our ARM Level 6 group (see photo below) had one of the highestlevel groups ever where all the candidates were successful and the average passing score was over 85%. The course was postponed until early/mid Octoberdue to lockdown but a winter storm cycle in the middle of the course provided some excitement and minimised ‘hazard scenarios'.

Back Row, left to right - Dave Lewis, Jack Lawrie, Ali Martin, Marius Bron, Char Tear, Jim Young (Course Instructor), Blair Findlay Front Row, left to right - Kim Ladiges, Troy Forsyth, Ted Stone, Erik Besselman, Kat Maceskova, Andy Corkill, Photo credit: Peter Bilous (Course Director)


NIWA's Winter Outlook By Ben Noll NIWA Meteorologist

“Winter is coming… eventually.” This is the message from NIWA meteorologist Ben Noll off the back of NIWA’s winter outlook, which was released earlier this month. “Last winter was our warmest on record. The nationwide average temperature sat just shy of a balmy 10˚C, which was 1.32˚C above the long-term average. This year, with warm sea temperatures, continued La Niña conditions in the Pacific, and increased northerly-quarter winds (northwesterly to northeasterly), we’re expecting elevated air temperatures and bouts of high rainfall for the coming months,” Mr Noll said. These conditions are not conducive to snowfall at lower elevations but can be a boon for snow at higher elevation. 2021 was disappointing for many winter sport enthusiasts, with snow depths at lower elevation (< 1500 m) being well below average, with none whatsoever at some sites. This made it extremely difficult for ski fields with bases at lower elevations, particularly club fields with no snow making facilities. In contrast, NIWA snow monitoring sites above 1500 m elevation all recorded average to above average snow during winter 2021. Mt Potts benefitted from a large dump of snow during May 2021, which persisted through the winter. NIWA’s winter outlook suggests that a similar pattern could happen again this season, as a consistent trend has cropped up for several years where rain, rather than snow, is falling at lower elevations in the mountains. However, Mr Noll caveats this, saying



that snowfall is governed by complex physical processes that extend beyond the traditional scope of NIWA’s seasonal climate outlooks: “This information should be taken with a grain of salt. Past La Niña winters have favoured wetter conditions in the North Island and have had mixed results in the western South Island, while being drier in the eastern South Island - every event is unique, he said. Astronomical winter officially begins on 21 June and while it may not feel like it, we may get a good dusting of snow later in the year. A helping of cold temperatures, moisture, and lift in the atmosphere, such as from a low-pressure system coming from the Southern Ocean, can cause instability as the cold air rides overtop the relatively warmer ocean and land surface, leading to the development of precipitation. This could bring local heavy, highelevation snowfall. So, while it’s not looking like the best year for hitting the slopes, Mr Noll says not all hope is lost. “With climatic similarities to the past two winters, a starting place for the upcoming winter might be a blend of the past two. More moisture may be available to weather systems in winter 2022 than in 2021 and 2020, so we may see higher snowfall this year.”

Mount Hotham Ski Patrol install first southern hemisphere Avalanche Training Center Rolf Schonfeld This past winter of 2021 the Mountain Safety Collective in Australia, set up the southern hemisphere's first Avalanche Training Center (ATC) at Mount Hotham, Victoria, Australia. Due to various restrictions, open times and lockdowns the Mount Hotham Ski Patrol had plenty of opportunities to get to know the ATC and hone their beacon and probing search skills and shoveling techniques. Despite Covid, over 250 exercises were registered by the control unit as not only Ski Patrol trainings but also public backcountry users, on mountain guiding services and the local avalanche safety course trainers as well as Victoria Police and Search and Rescue and even some Kids used the ATC. Bill Barker , Ski Patrol Director at Mount Hotham ski area, Victoria, Australia had this to say about the ATC: “The ATC resource proved to be a very effective and efficient avalanche rescue training area for our patrol team. Having the ATC ready to use at any time meant that, as well as running planned large scale rescue scenarios with many patrollers, we could also be very opportunistic and a single patroller or two could utilize the resource whenever time allowed. Having easy and ongoing access to the ATC for the winter, improved and consolidated our team's avalanche rescue skills, and we will certainly be utilizing it in the future.”

Key feedback points were: Burial of a transceiver prior to snow event.

Saves time as no scenario set up is required The ability to practice by yourself or in a group. Near real life scenario as ‘victims’ were buried as deep as 1.8m at one point which really tests probing skills! Allows searchers to practice different shoveling techniques to relocate ‘victims’. Flexibility to test a groups ability in search scenarios of varying complexity Easy to practice multiple burial scenarios, in the Hotham installationm case max.6 ( possible 5-16) Informative







backcountry tourers can easily practice avalanche rescue. Possibility of cross agency training scenarios.

An AST 1 course at the ATC board at Hotham. With a bit of snowscaping the area becomes a meeting point in bad weather.


Dispatch Recommendations The Avalanche Hour Episode 6.19 With Brooke 'Shiny' Edwards and Caleb Merril We loved this episode of the Avalanche Hour podcast. Brooke Edwards tells her story with such honesty it is hard not to resonate with her difficulties and challenges and above all, to come away inspired by her hard work and dedication to her career.

The Utah Avalanche Centre Podcast How Do the Young Guns Manage Risk? 19 February 2022 With Drew Hardesty and Zack Little In this somewhat groundbreaking podcast Drew Hardesty examines the mindset of the up and coming generation of backcountry enthusiasts. Drew gains some real insights into the relationship between the old guard and the new school backcountry skiers and riders. We reckon this is a conversation more people should be having!

Need a data fix? If you love graphs AND avalanches, then you gotta check out the Avalanche Incidents in New Zealand site by the NZ Mountain Safety Council. This is an in-depth look at 20 years of avalanche incident data in Aotearoa. The data is presented in easy to understand graphs and tables and illustrates trends and demographics in New Zealand avalanche accidents.

Now for a deep dive! If you have not visited the New Zealand Alpine Journal's Archives then you really are missing out. This is New Zealand's alpine heritage at your fingertips With over 122 (1892-2014) years of alpine history stored in its pages. You can even see an example from the archives on page 85 of this issue. The entire collection is at your disposal for FREE so get searching!



Dispatch Recommendations If you read one book this season then Snow Nomad by Alan Dennis should be it. Alan Dennis's memoir of his amazing and varied career will inspire and delight any reader. His account of creating the Milford Road avalanche program is of particular importance to kiwi readers as it recounts the early days of building a program in one of the most challenging avalanche environments on the planet. Whether you are a seasoned veteran or a snow safety newbie Alan's stories and insights will leave you stoked to keep pursuing snow and avalanches.

Resilience by Design by Ian Snape will completely change how you interact with your world. We all encounter stressful moments in life but Dr Snape dives deep, uncovering truths through modern science that contradict our common beliefs. Most notably of these is that stress is a human construct. It is something that we make up and once you believe this and get past your own preconcieved ideas of stress you can start to build resilience and flourish in stressful moments. This is a workbook and by design it is meant to guide you along the path to liberation. You won't regret it. For a small taste of Resilience By Design see pages 52-53.



Sheerdown S44 41' 41" E167 55' 41" ELEVATION: 1719 m photos courtesy of: milford road alliance 19 July 2021. Fiordland National Park, Southland New Zealand. This was a realtively young melt freeze crust that formed atop an older rain crust (buried ice layer) Cold clear nights and sun warmed days helped to coat the surface in 3-4 mm surface hoar. Below the ice layer was a 1 cm layer of small grained rounds. Below that, small grained (0.5 to 1 mm) facets had begun to form. Taht's a lot of kinetic growth taking place in just the top 3 cm of the snowpack less than a kilometre from the sea! According to Buhler's Crust Index (see page 62) this crust would have scored a 4 for interface bonding and a 5 for internal lamination although if similar meteorological conditions had persisted, we would have likely seen those ratings steadily decrease. This crust-facet combo did not become a known factor in any observed avalanche activity that season but it did show strong kinetic forces are at play in short time periods even in a deep maritime snow climate like Fiordland. - BC

Melt Freeze Crust

Ice Layer


Surface Hoar

Small Grained Rounds

Small Grained Facets 49

Stop Stressing About Stress IN ORDER TO MITIGATE RISK

By Gary Kuehn and Dr. Ian Snape

ABSTRACT A skier riding in trees needs to focus on the gaps while peripherally watching or listening for others. If they focus on the trees then they hit the trees. Similarly a focus on the negative effects ofstress (distress) can induce a nocebo effect, creat-ing more distress. This has two implications for risk: distress inhibits high-quality decision-making, and distress is a risk in itself for the health of avalanche professionals. By focusing on creating and maintaining resilience, we can eliminate the nocebo effect,minimize distress, and improve both risk-based decision making and the wellbeing of avalanche professionals. As avalanche professionals, our association with risk is personal. Our decision-making often occurs under pressure, is highly consequential, and most of us have direct experience of loss or trauma. Compared with the general population, the likelihood and consequences of risks are high. As Kristensen & Genswein point out in their 2012 ISSW paper, Perception of Risk in Avalanche Terrain, over a professional mountain guide’s 40 year career the chance of dying in an avalanche is 1:20, or higher if operating at increased hazard levels in consequential terrain.1 Eric Haskell & Darcy Solanyk in TAR 40.1 acknowledge that “Professional guides, rescuers, and avalanche forecasters are a unique subset...Their increased exposure to the mountain environment and other party’s accidents increase their chances of experiencing physical and psychological trauma.”2 In such a high risk profession, that role of stress (distress) is clearly critical for risk-based decisionmaking and as a response to workplace risk factors. However, there are three problems with the term ‘stress’: 1. Stress means different things to different people. For many, stress is a positive state of anticipation or action—this is commonly referred to as eustress. It is common to hear that people need a bit of stress to perform well. While for others, stress is more like the bad type (distress). And of course people can experience both and a wide variety of other states not called stress, as they respond to context in either well adapted or maladapted ways. 2. Stress is entirely created internally. As a term, stress is often used to describe an environment as a cause, or an effect (like a mechanism). Whether eustress or distress, both states are entirely our chosen response to the external environment. Whilst there is a strong correlation between workplace risk factors or adverse life events and stress, this relationship is not causative.3 Workplace risk factors for stress, burnout, and trauma for avalanche professionals include time pressure, consequential decisions, and death or trauma from friends, colleagues, and family. 3. By focusing on stress (implied to be of the distress kind), we predispose ourselves and others to create those sorts of states through the nocebo effect. Quite literally, stressing about stress creates stress! Excessive internal distress changes the ways our brains function and this is identifiable with neuroimaging and


Experts miss what they are not looking for. In this case, the avalanche gorilla is focussed on the trees and stress is a consequence! TIM ULEWICZ AT FRONTLINE MIND

biomarkers. We can also sense the changes ourselves: as increase in blood pressure and heart rate, sweating, inflammation, and speed while decreasing digestion and prefrontal cortex activity (where reasoning and critical thinking are mediated). In turn, that impedes effective decision-making. If we practice distress for a prolonged period, we will become prone to a range of illnesses, especially heart disease and early death.4,5 At the 2021 American Mountain Guides annual meeting, Jayson Simons-Jones compared [dis]stress to two scenarios: one being a “rapid loading event... you get 2” SWE overnight and everything falls down no matter how strong the structure is underneath and it’s kinda predictable,” in the other, “there is incremental loading... 2, 4, 6 inches of snow and maybe a bit of wind and you have the same end result where there can be a catastrophic avalanche.”6 Expressing stress, burnout, or trauma in terms of snow accumulation events is useful to a point—both single catastrophic events and multiple significant or cumulative events represent different workplace risk factors; however, that’s where the comparison stops. Unlike snow, that passively responds to the environment and our interactions, humans have agency. Snowpack doesn’t learn from past events and cannot choose to anneal and become stable, whereas humans can learn and exercise choice. There is no doubt that some people respond with distress when their otherwise

resilient state fails to cope, hence the correlation between workplace risk factors and internal distress. Such distress can occur in response to a single catastrophic event (the one rapid load event), or from many gradual experiences (like incremental snow loading). “Historically, resilience has been defined as a trait which is a constellation of personal qualities that protects individuals. These protective factors help individuals to withstand the pressure of the environments they are operating in.” 7 In much the same way that we want a snowpack that is resilient, especially to human interactions, “Incremental loading” allows more time for adjustment, healing, and metamorphosis of both the snowpack AND us! A better snowpack structure is more resilient to any loading in the same way that a resilient person’s robust base improves their adaptation after external pressures. Persistent weak layers of snow, by definition, take longer to become dormant, and may not be totally safe until flowing in the river. So rather than focusing or inducing states of stress, is it better to focus on developing resilience. Perhaps we have personal persistent weak layers? If so, one option is to choose safer terrain (with less exposure to workplace risk factors) until we develop resilience (where we can ‘anneal’ like snow). For dealing with the prospect of a heavy loading event or seemingly unending storm, we will manage better if we have built an established support network into our structure.

SUMMARY Stress is an internally created response. It does not adequately describe the environment or the interaction between the environment and our response. An external event that is stressful for one person may be neutral or even beneficial for another. Most importantly, stressing about stress will induce stress through the nocebo effect instead focus on resilience and what is needed to thrive in the operating context. Resilience is about having the choice of how to respond to challenges, and potentially having that good stress if it is useful to you. You can prepare yourself for some of life’s demands, whether these are many small challenging events or one large challenge. There will always be change. In seasons with a chronic persistent weak layer problem(s) we can plan for the reawakening of these layers in the spring and possibly look forward to their transition into the river. Maintaining resilience might be planning for change. It could be a change in focus or an entirely separate career path.

REFERENCES 1. Kristensen & Genswein, ISSW 2012, Anchorage AK; Perception of risk in avalanche terrain. 2. Eric Haskell & Darcy Solany, MS, PA-C. Post Traumatic Stress Disorder Prevalence in Recreational and Professional Alpine Sports: a Retrospective Study, TAR 40-1. 3. Snape, I. & Weeks, M. 2022. Resilience by Design: How to survive and thrive in a complex and turbulent world. Wiley. 4. Peter Attia. Podcast #190 Jan 10, 2022, Paul Conti, MD How to heal from trauma and break the cycle of shame; author of Trauma: the invisible epidemic: How trauma works and how we can heal from it. 5. Rich Sands Editor. Copyright 2020. Time Magazine, Special Edition: The Science of Stress: Manage It. Avoid it. Put it to use. Display until 8/21/20. Meredith Corporation, NY, NY. 6. Jayson Simons-Jones. AMGA Annual Meeting 2021. Workshop on Stress Injuries with Laura McGladrey, Jayson Simons-Jones, and Christian Santelices. 7. Harrison, D.; Sarkar, M.; Saward, C.; Sunderland, C.; Exploration of Psychological Resilience during a 25-Day Endurance Challenge in an Extreme Environment. Int. J. Environ. Res. Public Health 2021, 18, 12707. https://doi. org/10.3390/ijerph182312707 8. Drew, T. et. al. 2013. The invisible gorilla strikes again. Psychol.Sci. 24, 18481853.


Steve Schreiber An NZAD Interview


for over 40 years Steve schreiber has made his living in the mountains. Hes been a ski patroller, a ski guide and ski instrucor, an emergency medical technican and avalanche instructor and he's showing no signs of letting up. Where were you born and where did you grow up? I was born in Denver, Colorado. I grew up in Denver and other parts of Colorado (Aspen in summers, other parts of Colorado when the family travelled in Summer and Winter). When and where did you start skiing? I started skiing when I was 3 years old. Early days were at Hidden Valley in Rocky Mountain National Park, at Winter Park Ski Area and at A Basin. What was your first skiing related employment? I worked for what was called the Eager Beaver Ski School at Geneva Basin about 100kms west of Denver. I taught very young children when I was 14 and my first couple of years in High School. Where do you work now? This year, I am teaching skiing on Aspen Mountain. This is a good job. I decided to stop guiding for Aspen Mountain Powder Tours. The work was only about ½ time over winter in the northern hemisphere. In New Zealand, I am guiding and doing snow safety for Soho Basin. I am also a partner and director for Peak Experience using my sole trader business: What is 45 South Ski Guiding? I am a shareholder in “Peak Experience”. The way it works is we set up our own company and work under “Peak Experience” which includes permits, insurance, etc. The website is The permit includes pretty much all DoC estate on the south island. Just opening for business this season so looking for clientele at present.

How did you get started with working in the ski industry? I had a great mentor as a kid. Abe Polonsky gave me a chance to work with young kids. I started working full time after graduating from the University of Colorado and after trying to do a normal job. Working in an office just did not work for me… Who were some of your other mentors or inspirations in your career? I have had many mentors. In the States: Rod Newcomb and Peter Lev from the American Avalanche Institute and Rob (Bunky) Baxter rom the Aspen Mountain Ski Patrol helped me to develop avalanche related skills. I was also mentored by Erik Peltonen of the Aspen Mountain Ski Patrol after my avalanche accident when I was 40. In New Zealand, early mentors included Bill Atkinson, John McNamee, Andy Harris and heli pilot Alan Bond. After I joined the NZMGA, many others helped me to learn; Kevin Boekholt, Nick Cradock, Guy Cotter, Gottlieb Braun-Elwert to name a few. What is the biggest change in NZ skiing since you started? Modernization…my first year in NZ was 1985. Since that time, new lifts, snowmaking, grooming have become commonplace. There is also a larger group of professionals in the industry.


Where is your favorite place to ski? I really like skiing in the backcountry. It does not matter where. All venues have great qualities. What event in your career has had the biggest influence or impact on you? Probably the experience of being caught and buried in an avalanche when I was 40. I was working in Canada. I injured my knee and other parts of my body. But I learned so much about good judgment and decision making, especially from many colleagues in NZ after I returned from surgery and rehab in Aspen. You were caught and buried in an avalanche and injured? Could you elaborate? 24 years go in Canada while working at TLH Heliski. We went out in the morning and were triggering sz 2-3 slabs. We sent the guests home and did assessment and ski cutting. On our last run, we were ski cutting a run called Playoff. The slab release behind me and I was caught and went for a ride. My left ski did not come off and I was injured. I drove home with my Mum to Aspen and had knee surgery (Left ACL and meniscus). I did rehab for the next 4-5 months before returning to Methven. Lessons learned: ski cutting should be done only where small avalanches are expected. Making decisions such as this, late in the day, should never be taken. Best to quit early so the decision making process is done when well rested. What would you tell someone starting out in the snow/avalanche world today? It is a great career. It requires focus, dedication, and incredible humility. What would you tell your 20-year-old self today if you could? Hard question, I was a pretty overconfident kid. Looking back 45 years, I have made many mistakes... I wish I had known more then as I think, I would have studied more geography than I did then. What gives you the most satisfaction in your work? Spending time in soft snow. I just love it. If you couldn’t work in the ski industry anymore, what would you do? I am near the end now. Working outside is my thing. I guess something that lets me appreciate the environment. Where have you skied outside of work? I have skied in North America quite extensively; done a bit of freelance guiding in Chamonix, Saalbach-Hinterglemm and on the Brenner Pass. I have also skied (in Europe) recreationally: Les Arcs, St. Anton, Argentierre, Val di Fassa; Trish and I went ski touring in India (Himachal Pradesh, 1992); and of course throughout NZ.

On our last run, we were ski cutting a run called Playoff. The slab releaseD behind me and I was caught and went for a ride


IWhat was the idea behind the Crystal Ball and who else might have been involved in the creation of it? I inherited the production of the Crystal Ball. It was a production of the Snow and Avalanche Committee (SAC). It was a collaboration between academia, industry, government and education providers such as Otago Polytechnic along with the MSC. The idea was to share new avalanche thinking within NZ but also from events such as ISSW and colleagues from the CAA and the AAA. What was your role in the early days of the New Zealand Avalanche Advisory? Big question, firstly after my accident in Canada and subsequent to a few issues that affected the team at Wilderness Heliski, I thought the industry needed a means to share ideas in a coordinated manner. I spent some time in Revelstoke discussing the origins of the InfoEx in Canada with Alan Dennis and Ian Tomm. Taking these lessons to New Zealand, I approached the SAC in Te Anau at one of their meetings and Alan Trist and Ian Owens supported my starting an early beginning to a NZ InfoEx. Over the next 10 years, I became an employee of MSC. My job started with sharing information but evolved into a public advisory programme as well (, regional forecasting, national media…). As time evolved, I also became involved in working with the ski industry on safety issues. We also supported accident investigations (Turoa, TC, etc.). And towards the end of that time, the alpine programme was added to my brief. The most difficult aspect of the work was getting as many players involved as possible. Some of those aspects included developing the Avalanche Education Working Group, bi-annual southern hemisphere workshops, developing a diploma programme (in conjunction with OP and Skills Active), etc. As far as insights, my best recollection is that under Dave Morgan, the programme was going well. But Dave moved on and Trist was letting the programme fade. My involvement with the SAC helped rekindle interest.

What brings you the most happiness in life? Being able to work in the snow. I have had a good run. What has been your favorite make and model of ski? Not an easy question. Skis and boots have change so much over my lifetime. I learned to ski on leather boots and wooden skis with screw in edges. At present, I am skiing Kastle and G3 skis, Dalbello and Dynafit boots. Pretty good options. What is a piece of skiing equipment that you cannot live without? Good boots are key to success. What is the biggest challenge facing the NZ skiing industry currently? Covid has shown us that kiwis will ski when they cannot travel. This has put the industry in a corner as lift queues and roads are at capacity. The challenge is how to service that demand and how can the industry adapt to additional pressure from overseas clientele? How do you prepare for the start of a winter season? I try to rest from the previous season. I have been skiing most of the year since 1985. It is not easy as I grow older. I also try to get to the gym for about 6 weeks prior to each winter. Of course, mountain biking is a great way to keep fit. Before you go out on the snow for the first time of any season, what do you do to start forming a picture of the snowpack? Firstly, I watch the weather events (snow, wind, temps). The patterns give me an idea of what to look for (DH, water content, HS). Then I spend time looking at surface features, digging as many profiles as I can so a theory evolves as to weaknesses, etc. Once you get out on the snow for the first time in a season, what information do you start to look for? Biggest issues for me are layering and effects of early season snowfalls (faceting, depth, wind effects). I also look at anchoring.

The challenge is how to service that demand and how can the industry adapt to additional pressure from overseas clientele?

Have you noticed any particular trends in the NZ snowpack over your career? The weather and climate have changed. It is much milder than 30-40 years ago. Long term this could be a threat to viability for the industry. Shallow snowpacks can be more dangerous. Shallow thin snowpacks are becoming more normal in lots of the Western US and I am wondering if you see that trend more and more here in NZ? I do. Last season was classic. Shallow snowpack left both facet layers and ice crusts from solar and rain events. Mid winter we saw significant new snow overlying the early season snow layers. Lee to NW, we saw wind slab and this proved to be significant.


Have there been any persistent weak layers in snowpacks you have worked in that were particularly challenging? Again, classic: buried surface hoar, variety of crusts, depth hoar. Has this ever significantly challenged your ski guiding work? Or has terrain been the answer? These layers can be players but must be coupled with terrain factors (challenging and complex; lee slopes…) What do you do when you aren’t skiing or working in the NZ winter? I like to camp and ride my bike. I also enjoy playing golf and I love to travel when I can. Covid has made this more problematic. Can you describe your most difficult day of guiding work? Long term, I guided my wife out of Kelman Hut in a white out. She needed to get to CHCH to fly to Europe for a conference. We had waited out the weather, but the white out would not move on. White out navigation was hard enough. Finishing the day after dark when Trish was exhausted made for a long day. Can you describe a “favourite day” of guiding work? It has been a long career, so my recollections are often distant. But I can recall one day in Canada and one day in NZ. The Canadian day was heliskiing with group of snowboarders. They wanted to max the number of runs. This was an epic day. In NZ, I have had may great days. But I had a wonderful day working for Wilderness Heliski that lasted almost to dark with 2 private clients. The skiing was great, I have always enjoyed runs in Gorilla Stream, Abbey Pass, the Scorpion Glacier, etc. How has the Covid 19 pandemic affected your work? I have been in isolation 4 times. 2 were arriving in Auckland. But the other 2 were imposed by government in NZ and Colorado. This was especially difficult as not being able to work for weeks at a time was frustrating. What (if any) “Golden Rule” (or rules) guide you in your work or life? I always question my own decision making by asking myself: “Could I be wrong?”.


Are people relying too heavily upon tech and equipment or is it actually making the backcountry better/safer? Not really sure. It certainly has increased participation. Websites are inspiring new recreationists, but I think kiwis are struggling to afford items like airbags, advanced transceivers (Barryvox) and touring gear. Tech versus training will be a primary issue into the future. As for better/safer we need to focus on training. Tech is good but greater understanding of the risks and the issues we all face is primary. Have there been any significant surprises or learning moments in your career? Either avalanche related or not. What were they? It seems like learning is a constant. Certainly, experiencing a near death moment when I was guiding was very important. But losing friends both in NZ and overseas has also been very important. It has shown me the decision-making process that others employ and it has helped me with my own. Gaining more backcountry touring experience while staying safe can be a bit of a Catch-22 scenario. What tips do you have for newer folks that want to backcountry tour more but also be as safe as possible doing so? Focus on team-oriented decision-making is critical. Overseas, ego seems to be a major issue. Many are keen but lack training. Winter of 2020-2021 in Colorado was as deadly as has been seen for many years. I skied with four guys from Portland yesterday who are keen backcountry skiers but they all lacked training and did not seem to have any desire to learn about the risks and the process of understanding. All were between 40 and 60 years of age. They did have good skis, boots, etc. but were not great skiers and they did not seem to know that paying attention all season is critical to their own personal safety. Do you have any post Covid 19 preparations in store as the borders reopen? I got the Moderna vaccines and booster. I am not sure how to insist clients do the same. I hope Omicron follows a similar course as it did overseas. Seems like it was a milder variant and after a fast highly contagious phase it faded away just like the flu. Here’s hoping...


Technology and equipment continue to “open-up” the backcountry like never before. Have you seen any trends along this line in NZ or elsewhere? I.e. Are people relying too heavily upon tech and equipment or is it actually making the backcountry better/safer? Not really sure. It certainly has increased participation. Websites are inspiring new recreationists, but I think kiwis are struggling to afford items like airbags, advanced transceivers (Barryvox) and touring gear. Tech versus training will be a primary issue into the future. As for better/safer we need to focus on training. Tech is good but greater understanding of the risks and the issues we all face is primary. Have there been any significant surprises or learning moments in your career? Either avalanche related or not. What were they? It seems like learning is a constant. Certainly, experiencing a near death moment when I was guiding was very important. But losing friends both in NZ and overseas has also been very important. It has shown me the decision-making process that others employ and it has helped me with my own. Gaining more backcountry touring experience while staying safe can be a bit of a Catch-22 scenario. What tips do you have for newer folks that want to backcountry tour more but also be as safe as possible doing so? Focus on team-oriented decision-making is critical. Overseas, ego seems to be a major issue. Many are keen but lack training. Winter of 2020-2021 in Colorado was as deadly as has been seen for many years. I skied with four guys from Portland yesterday who are keen backcountry skiers but they all lacked training and did not seem to have any desire to learn about the risks and the process of understanding. All were between 40 and 60 years of age. They did have good skis, boots, etc. but were not great skiers and they did not seem to know that paying attention all season is critical to their own personal safety. Do you have any post Covid 19 preparations in store as the borders reopen? I got the Moderna vaccines and booster. I am not sure how to insist clients do the same. I hope Omicron follows a similar course as it did overseas. Seems like it was a milder variant and after a fast highly contagious phase it faded away just like the flu. Here’s hoping...


Crust-Facet Forecasting Thoughts By Don Sharaf Theis article first appeared in The Avalanche Review 40.4 and is reprinted here by permission.

Lynne: “So I heard you did a talk for ESAW about crusts and facets.” Don: “Ummm… yeah… and…” Lynne: “Would you be willing to write an article for TAR…” What was I thinking? Great brains are studying faceting around crusts and we still don’t know when they are strong enough. We still don’t know whether cutting the crust during the stability tests creates an unrealistic picture of propagation potential. “We” don’t know much and I feel like I know less. So what could I write that might be helpful? What follows are a few anecdotes, resources, and questions that I hope will spur your curiosity and help you consider all possible outcomes when dealing with facet crust combos. The starting point. Crusts are strong and Facets are weak. This simple statement is the source of a big problem. If you have facets below a crust, then the slab that needs to be built to cause weak layer failure is likely going to be BIG. Scott Savage presented a fascinating ISSW talk in 2006 on Deep Slabs at Big Sky Resort in Montana. Among his data set, 100% of the deep slab avalanches were associated with a crust or ice. Wow! I was just working there a week ago and the persistent weak layer within the snowpack at treeline and above was a crust-facet-crust sandwich. The current Big Sky snow safety team, Mike Buotte and Chelan Babineau-Z, were facing a question they face almost every year: How much load will tip the balance, or will it tip at all? I don’t know. Crust-facet stability is difficult to predict and it takes constant vigilance as loading and subsequent slab character changes.

The variables and the most important questions to ask when trying to assess your problem: How did the crust facet combo form? If you know this, then you have some ideas on distribution. Rain event on pre-existing snow with a cooling trend at the end of the storm. You likely are going to see a set up for Melt-Layer Recrystallization. This pattern is elevationally driven. All rain and no snow will result in a thick rain crust when the storm ends and cold temperatures return. All snow and you won’t have a warm layer where liquid water exists. The future problems can be found in those transitionary elevations that have had rain and then a thin layer of snow at the end of the storm. I have seen this confined to 1000’ vertical, but have also seen it span 2500’ (Dam Facets, TAR 33.2, December 2013). With an elevation-driven problem, you don’t have safe aspects to run to – your only recourse, as a nonmitigator, is to limit slope angle.

This was the 12/28/2011 rain crust over basal facets/depth hoar. The photo was taken on 1/8/2012, so the facets beneath the crust were the result of around 11 days of that process.

Rain event on pre-existing snow. Rain-soaked snow freezes into a crust and then a layer of snow sits on top, exposed to diurnal faceting near-surface gradients. This problem is going to be a little more aspect-driven, especially if there was any wind associated with the snowfall. South aspects might cook into sun crusts or, if cloudy, may have rapid diurnal facet growth. Leeward aspects to the wind may hold a thicker layer of facets or may be so dense that they were resistant to faceting. Windward may not have any snow at all and not present a problem for the future. Sun-formed crusts usually pair with radiation recrystallization facets – In terms of distribution they are often aspect-driven. Steep slopes and high elevations lead to rapid facet growth over what will become a very thin crust. In my experience, these layers react so quickly to load that they seldom develop deep slabs.


Other insights into crustt-facet layers: Facets around a crust due to micro-scale temperature gradients. Ethan Greene (2006) and Kevin Hammonds (2016) have done great work showing that faceting occurs on either side of a crust and that thermometers are poor tools to assess those gradients. The scale of the kinetic gradients is within millimeters of the crust, so that gradient remains undetectable to tools that are designed for a larger scale and lower precision. The bottom line here is that visual inspection of the grains is the best assessment tool and that you are going to have to dig to that layer to assess it over time. Have you ever wondered what causes crusts to ‘decompose?’ Well, that is likely due to strong gradients immediately adjacent to either side of the crust. So what? A crust that initially was strong enough to support additional load may lose strength over time AND the grains around that crust may become facets… or even bigger facets. Elevation and aspect aren’t helpful here – you have to dig and assess if you are seeing results in your stability and propagation tests, or if you suspect there could be a future problem. Age and size matter: A study by Bruce Jamieson and Paul Langevin (2004) looked at avalanches associated with crusts. They found that new snow (PP and DF) avalanches on a crust were a shortlived problem (no longer than six days from time of burial). In the scope of their study they noted that 94% of the avalanches that occurred on crusts were associated with persistent grain types. Surface hoar on a crust proved to be more persistent (lasting up to 33 days), but facets associated with a crust had the greatest longevity with avalanches to three months following burial. As an aside we saw a wet slab cycle in the Tetons reawaken a facet crust combination 123 days following the formation and burial of that layer! Some commonalities between Jamieson’s and Savage’s observations is that the weak layer thickness of the facet layer is commonly 2 cm or less and that the grain size of the facets is 2mm or less. Jamieson did observe that larger facets often were responsible for the avalanches that occurred the farthest out from burial. So how thick a crust is thick enough to prevent further avalanches? It really doesn’t matter if the facets overlie the crust, but if the facets are below, then it is going to take larger and larger loads (or triggers) to affect those facets. With the infamous MLK crust of 2011 it took massive loads to cause the crust and weak layer to fail. Crystal Mountain saw massive wet slabs running down to that layer (Morin 2012). I wish I could say a crust of a given thickness and hardness is going to lock down everything below that layer, but it really does depend. One factor I consider when pondering this question is the likelihood that rain crusts will likely decrease in thickness as elevation increases. With this increase in elevation the slab depth overlying the crust will also likely increase (due to higher precipitation and wind loading). Consequently, the lower and mid-elevations may remain locked down, while the highest elevations might be susceptible to reactivation. That was the case in the Wasatch with the MLK layer later in the season. (Nalli 2012, Havlick 2012)

Consistent Observations and Communication Ryan Buhler et al (2012) came up with a crust index (see below). Using this index to observe crust layers over time will give you some physical properties to track as the snowpack stability improves or degrades. Crust Index definitions. The interface bonding describes the bonding between a melt-freeze crust and the layers above and below. The internal lamination describes the bonding between grains within a melt-freeze crust.


So what? Facet-Crust combos are persistent problems. Not only are they capable of producing large avalanches, but they can be a problem that lasts all season. If an avalanche flushes down to the crust layer and then a little bit of snow sits on that bed surface for enough time for diurnal faceting to weaken it, then you have strong potential for a repeat offender that season. This structure is also a great set-up for being the “funny business” that Reardon (2004) referred to in his initial study of wet slab avalanches in Glacier NP, MT. Having both a high porosity, low strength weak layer over a water drainage barrier is a great set up for wet slab formation. Liam Fitzgerald said some words that stick with me, something to the effect of “If you have a layer that has been a problem throughout the season, then watch for it again when spring hits..” I hope this article has given you some things to think about when pondering next steps with your current crust facet mess. As I have said, I don’t have a lot of answers, but I do have some specifics to think about as those layers evolve and the slabs build. Hopefully this focuses your curiosity. “Good luck with those rotten bastards!”

References For a great overview of crusts, read The Avalanche Review 30.3. TAR archives can be found in the top bar at Also, the following references are great to dive deeper into case studies and research on crusts, facets, and avalanches: Buhler, Bellaire, and Jamieson, 2012, Tracking Melt-Freeze Crust Evolution, Proceedings of the International Snow Science Workshop, Anchorage, AK, 84-91 Greene, Shneebeli, and Elder, 2006, The Microstructural effects of Kinetic Growth Metamorphism in a Layered Snowpack, Proceedings of the International Snow Science Workshop, Telluride, CO, 22-26 Hammonds, Kevin, 2014, Laboratory Investigations on the Thermophysical Properties of the Ice-Snow Interface While Under a Controlled Temperature Gradient, Proceedings of the International Snow Science Workshop, Banff, AB, 35-42 Havlick, Ian, Wasatch Rain Crust Event. MLK 2011, The Avalanche Review, Volume 30 Issue 3, pp. 27-29 Jamieson and Langevin, 2004, Faceting Above Crusts and Associated Slab Avalanching in the Columbia Mountains, Proceedings of the International Snow Science Workshop, Jackson, WY, 112-120 Morin, Christopher, 2011, The MLK event at Crystal Mountain, Proceedings of the International Snow Science Workshop, Anchorage, AK, 2012, 240-243 Nalli, Bill, MLK Rain Crust, Deep Slabs and Cornice Failure in the Southern Wasatch, The Avalanche Review, Volume 30 Issue 3, p.26 Reardon, Blase, 2004, Forecasting for Natural Avalanches Suring Spring Opening of the Going-To-The-Sun Road, Glacier National Park, USA, Proceedings of the International Snow Science Workshop, Jackson, WY, 565-581 Savage, Scott, 2006, Deep Slab Avalanche Forecasting and Mitigation: The South Face at Big Sky Ski Area, Proceedings of the International Snow Science Workshop, Telluride, CO 483-490 Sharaf and Janes, 2014, The Evolution of the 2014 ‘Damalanche’ Facet Layer of SouthCentral and Southeast Alaska, Proceedings of the International Snow Science Workshop, Banff, AB, 55-62

Let us know what your experiences with crust-facet combos here in Aotearoa have been like: 61

Dave y e l n i K Mc ster a c e r o F A NZA nt u o M / i k a r Ao Cook Area

Dave McKinley and his avalanche search dog Stellar.

Can you describe your avalanche safety background? I have been involved with analysis of avalanche terrain, both recreationally as an Alpinist, skitourer and ice climber for 35 odd years, some odder than others. Professionally I have been involved with running Avalanche Search Dogs for around 30 years and guiding since the early 1990’s.

How did you get into avalanche forecasting? I had some involvement with writing avalanche forecasts soon after the NZAA was set up and became a regular forecaster for Aoraki, Ohau and the Two Thumbs Ranges when the oversight of the program was undertaken by Alpine Guides Ltd.. Aoraki is the one region that continues to forecast year round.

Besides avalanche forecasting, what other work or activities are you involved in within your region during winter? Winter is a busy time with the Mt Cook Heliski season being in full swing, plus touring work and search dog training. Any free time is spent with the family.

What are the best things about winter recreation in your region? Everything! We have the best snow, elevations and terrain to play in.

What are the most challenging things about winter recreation in your region? Main Divide weather and very complex terrain, glaciation etc make for challenging decision making all of the time in this region.


The Aoraki/MtCook forecast area for thr NZAA. The Alpine Guides forecast team also writes daily forecasts for the Ohau and two Thumbs Ranges.

What are the unique challenges for forecasting in your region? We are forecasting for three very different areas with a huge spacial and climatic variance including valley floor to over 3000m elevation bands.

What are some of the most overlooked avalanche safety points in your region that you typically see or hear about? The single biggest overlooked point is awareness of what can lie above the zone people are travelling through. There is also a lot of serac avalanche activity which is very hard to predict as well as many “don’t take me there” areas where even small slides can have big consequences such as in crevasse terrain.

In general, who are the user groups in your region? A large sub-section of people in the National Park and adjacent Conservation areas are quite well skilled and knowledgeable, which is great, ski tourers, alpinists of all ages and gender, mostly in small groups. There are some general tourists who do wander in avalanche terrain in winter with no idea they have, but they are smaller in numbers and often from overseas.

If there was one unique takeaway winter backcountry users should know about your region what would it would be? Take the gear, education (take a course) and ask the locals.

Any personal winter objectives in 2020? Snow.


Evaluating Tap-test Force for Extended Column Tests and Compression Tests Mark Sedon This article was first published in the Canadian Avalanche Journal.

Introduction After well over two decades in the guiding and ski patrol industries, teaching courses, and running guide training, I’ve noticed how avalanche practitioners’ tap-test forces vary significantly. We have our documented standard sizes for extended column tests (ECT) and compression tests (CT), and a clear descriptive explanation of how to perform the easy, moderate, and hard tap tests, but it occurred to me there is no known documented level of force that should be applied through each tap test on the shovel. Why should we care? There are several reasons: Do we all use the same force? Do we use the same force for left and right hands? Is our technique correct? Do we tend to tap harder in an avalanche course than we do at the top of an epic looking powder run? During the recent Southern Hampshire Alpine Conference in Wanaka, New Zealand, I decided to gather some measurements and give some feedback on techniques. We also came up with an average newton of force applied for each test. The two biggest variables over the two days were a highly experienced ski guide who by his own admission hadn’t done a snow profile or test in four to five years (very surprising to hear) and whose taps were so light I’m not sure they’d wake someone up from a nap on the couch; and a very experienced avalanche instructor who beat the shovel so hard a panel beater was almost needed to straighten it out.

The Measuring System Graph 1. Showing the distribution of Wrist, Elbow and Shoulder taps across all respondents.

While looking for a way to measure the newtons for our tap tests, I came up with two ideas. First was a musical drum and a decibel measuring app on an iPhone. Second was a scientific testing machine from Otago University. Fortunately, we ended up with the scientific equipment. The setup consisted of a bending beam single point load cell (manufacturer PT, model PTASP6-D 40kg) connected to a weight indicator (EMC 2060 with analog output option). The analogue signal was connected via an AD Instruments Powerlab 4/26 and displayed and recorded with LabChart 8 software on a laptop. The force was calibrated in newtons. A thin glove was placed on the shovel to replicate the practitioner with a gloved hand. The display on the PC would show the tap force for all 10 taps in graph form, with the readout showing just the highest force. This was an unmodifiable setting that might not be ideal. An average of the 10 taps might have been better, but you could look at the graph and see if a practitioner had even taps quite easily.

Results We tested 69 avalanche practitioners, the majority being ARM Level 6 certified. The results were studied by Shane Galloway, a recreation researcher and consultant. Galloway commented that there was no statistically significant difference between the participants based on qualification level or student/trainer status. Numerically the trainers and Stage 2 participants were more consistent, but not enough to make a statistical difference. However, the test did not take into account the practical difference these force measurements have on the show pack.


Mistakes I’ve Seen These are mistakes I’ve seen while observing people conduct tap tests throughout my career: Remember, you should NOT be looking at your hand. Watch the column of snow! Long, bendy saws often don’t cut the back wall parallel. Damaging the column strength when trying to cut the top flat (hard surface). Hitting too hard (ECTP30’s still a sign of instability). Wrist comes off the shovel in soft taps. Trying to keep elbow on shovel handle for moderate taps. Bending arm and brutally bashing shovel on hard taps. Taps gaining strength from 1–10, 11–20, and 20–30. Hard taps are not an excuse for releasing stress! With an ECT, we really don’t want a result. Keep your hard tapping technique in check, lock that arm straight and don’t use your torso.

Graph 2: Showing the mean Newtons applied per tap from elbow wrist and shoulder.

Hard taps can be done wrong if the arm is allowed to bend. This was the case for 90% of practitioners witnessed. Almost everyone went wild on the hard taps and beat the shovel like a 1980’s mogul skier’s knees. Only the people who kept their elbow locked straight consistently applied the right force. The average force for a hard tap was 135 newtons. Fig 1: Note how the force does not drop back to zero between taps due to the person resting their wrist too heavily on the shovel.

Standardizing Tap Force With Tools I wanted to look at ways we could standardize tap test forces. Myself and Whitney Thurlow, a fellow IFMGA climbing and ski guide, had a think about what we carry with us as guides that would double as a weight to drop on the shovel. We tested a ski pole, dropping in handle first onto the shovel. Dropping it from a fist width above the shovel gave repeatedly accurate light taps (25N) and dropping it from 30cm above the shovel gave it a near perfectly equal moderate tap force (60N). This needs more research if and when a standard tap force is accepted.

Conclusion Fig 2: Note the wide bottom of the tap force, a ‘push tap’.

Summary Good technique generally produced similar newtons of force regardless of the person’s size, anger, sensitivity, or which hand is used. Do training together to standardize and check everyone’s technique. When doing a light tap, about 10–15% of people let significant weight from their wrist rest on the shovel so that when they did their taps, even though their technique was good, the force applied from the taps was significantly higher. See Fig. 1 below. The average force for soft taps was 25 newtons. Ten to fifteen percent of people did a type of what I called a ‘push tap,’ where they tapped the shovel and held the weight there for a fraction of a second instead of tapping and releasing. I don’t know which is right or wrong, but this action applied generally more pressure to the shovel. See Fig. 2 and notice how wide the force graph is. For moderate taps, the standards say we should use fingertips or knuckles but 90% of people used their flat hand. There seemed to be no reason not to use the flat hand as the newtons applied was actually more consistent. Maybe the standards should be updated to include a flat hand? The average force for a moderate tap was 60 newtons.

Most participants spoke of how useful the workshop was for gauging their own tap force. Once we had a baseline, feedback was offered and I could see how it gave people a way to focus their technique. Even just having me standing there watching technique allowed people to improve. Regardless of what the newton force is, that procedure definitely narrowed the range of tap force. Having the device at future avalanche conferences is a great way to standardize tap-test forces and also discuss technique. At the end of the day, I think using the proper technique described in the guidelines does keep us within an acceptable range, but checking this technique in pairs is important to weed out bad habits. The next step is to see what force North American and European forecasters apply to see if an international newton force can be agreed on. It’s not about waking up a sleeping colleague, or panel beating a shovel—it’s all about consistency.

Thanks to: Shane Galloway, a recreation researcher and consultant. Barrett, Technical Leader & Electronics Technician, University of Otago. Tom Harris, NZ Mountain Safety Council.


Wind Slab or By Ryan Leong Whakapapa Ski Area Snow Safety Officer

The aim of this article is to give my opinion on the storm slab vs wind slab issue, show how I differentiate between these two types, and the reasons why. But it’s just that - my opinion. Feel free to agree or disagree, and throw in your two cents if you want. For many years, there has been varying and inconsistent use of the storm slab and wind slab avalanche types. One operation, or person will call a certain condition a wind slab, whereas another operation or person will call the exact same condition a storm slab and vice versa. It has been a hotly debated topic, which when you step back can seem like a pretty esoteric exercise. But I'll have a stab at it nonetheless… Let’s start with the definitions from the NZ guidelines: Storm slab Release of a soft cohesive layer (a slab) of new snow which breaks within the storm snow or on the old snow surface. Storm slab problems typically last between a few hours and a few days Storm slabs that form over a persistent weak layer may be termed persistent slabs or may develop into persistent slabs Wind Slab Release of a cohesive layer (a slab) formed by the wind. Wind typically transports snow from the upwind side of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer may be termed persistent slabs or may develop into persistent slabs

The most common contradictory use of these avalanche types I see is when there is new snow falling with wind at the same time which will transport it onto lee slopes creating a slab. This sometimes gets described as a storm slab because it involves new snow falling from the sky, whereas it may also be called a wind slab by other folk. My view is that this is a wind slab because the wind effect is the main thing that dictates the slab qualities (where it is, what it looks like, how it behaves etc). I don’t think it matters whether the wind blew that slab into place (a) as the snow fell out of the sky during the storm, or (b) a day or two after the snow stopped falling. The end result is the same, and you would manage it in the same way. Why does it matter what we call it? One of the key benefits of having the various avalanche characters (wind slab, storm slab, persistent slab etc) is that they describe a specific type of avalanche which has its own traits - how it is created, what it looks like, how it behaves, how you manage it etc. If the given avalanche develops, appears, and behaves consistently, but we are sometimes calling them different things, that can be pretty confusing for the end user. If however the avalanche problems are used consistently it can be a big help. For example, if someone tells me that I need to be looking out for wind slabs I know that as a starting point I am going to be looking for patterns of slab distribution across aspects, avoiding lee slopes, using windward slopes for safe travel etc. I will know to possibly expect stiffer slabs that might have the potential to hurt me more if I get caught. There can always be variability and I may find some areas of soft, evenly distributed (storm) slab if I come across a really sheltered area. But, for the most part my


Storm Slab?


senses are tuned into where the wind has been blowing in the local area and I will build on my info from there. Start looking at how deep it is, how the depth changes across those lee slopes, how well bonded it is etc etc… If someone tells me there are storm slabs out there I will be anticipating much more widespread areas of softer slab on many aspects with fairly even distribution within each terrain feature. I'll be anticipating easier skier triggering and provided that the slab isn't too deep, the slope too big, or that there aren’t any nasty terrain traps I can probably get away with getting caught in a small slide because the debris will be quite soft and break up easily. Good conditions for using ski cuts on safe slopes. I’ll be keeping a keen eye on any increase in wind that could quickly start to shift this nice soft snow and change things into wind slabs and increase the hazard. There may be some anomalies that might fall outside of these conditions that you need to be looking out for, but in general knowing what you are dealing with dictates how you behave around avalanche terrain. Here’s a quick background to add a bit of context… In 2004 Roger Atkins published a seminal paper in which he came up with the idea of avalanche characteristics. These were based around 27 different regimes which were spread under eight main groups. For example under Wind slabs, there are Wind slabs near ridge tops, katabatic wind slabs, hidden (buried) wind slabs etc. His main motivation for writing this paper is that he felt there was excessive attention to danger ratings, and little or no attention to the characteristics of the avalanches that were likely to occur. This paper proposed a way of better communicating the complexities and subtleties of stability and danger ratings, rather than just saying stability was ‘fair’, or the danger rating is ’moderate’ (remember this was in 2004 when we still used stability ratings). Here’s a particularly good quote from that paper: “Communication is a two part process, ideas need to be expressed clearly, but communication is not complete until the message is received and interpreted correctly.” Most of the world then caught on and adopted and refined these avalanche characteristics over the coming years as they became integrated into avalanche bulletins, snow safety operations, and our common language. The Europeans and in more recent years the Utah Avalanche Centre have moved away from using ‘wind slab’ and ‘storm slab’, and instead go with “wind drifted” and “new snow” avalanche problems as well as three additional problems. But for the most part New Zealand, and the other countries that our avalanche scene seems to follow (Canada / US) have a fairly similar description of the various avalanche problems, to varying levels of detail. In 2010 Roger Atkins, Karl Klassen, and Pascal Haegli published a series of documents which go into further detail for each of the avalanche problems as background to the ‘Decision making in Avalanche Terrain’ field book published by the Canadian Avalanche Association. These documents cover a general introduction, activity patterns, recognition and assessment in the field, and risk management strategies for each of the avalanche types. Just to push my case further, for wind slab development they state “Wind slabs develop where there is sufficient wind to transport falling snow or surface snow. For wind slabs to form there must be snow falling dring the wind event, or there must be loose snow on the surface available for transport”. Around the same time the Colorado Avalanche Information Centre put out this nice little flowchart to provide guidance to forecasters around which avalanche type to apply.


Jump forward a few more years and Grant Statham and others came up with the Conceptual Model for Avalanche Hazard - which has become the international standard for how we assess and communicate avalanche hazard. In that paper there is a ‘type of avalanche problems’ table which also lays out the differences between the problem types, how they are formed, what they look like, and how you manage them (see below). This quote from the’ type of avalanche problems’ section further explains the importance of getting our use of these problems correct: “These different types of avalanche problems are repeatable patterns, formed from a disparate set of snowpack, weather and even terrain factors that require distinct risk management techniques. Recognizing these patterns and distinguishing between the different types of avalanche problems is a fundamental tenet of effective avalanche risk management, and the first step toward characterising an avalanche problem in the CMAH.”

Below are some links to various papers and documents mentioned above. Worth a read if you are interested. As I said at the start, this is just my opinion, but hopefully the reasoning at least makes sense. Hopefully putting this out there will generate a bit of discussion and lead us to a more consistent use of storm slab and wind slab, because I think there is a lot to be gained from that.

Do you have something that you'd like to say on this topic? Send us your thoughts and observations:


WTF! My Beacon is Broken! An Initial Look at Transceiver Interference with Search and Rescue Considerations By Ivars Finvers and Doug Latimer This article first appeared in the Canadian Avalanche Journal.

FOR YEARS THE AVALANCHE INDUSTRY has been aware that electronic devices may interfere with an avalanche transceiver search [1 -4]. Despite this, many users are still unclear which devices may impact a search, and there are no identified strategies for dealing with interference during a search. We evaluated a number of potential sources of interference in the field and propose some practical search strategies to address them. The purpose of this article is to: 1. Identify and quantify potential threats to a clean signal search. 2. Begin a meaningful discussion on how to mitigate signal interference. 3. Introduce possible search strategies for a buried victim when interference is present.

Warning This is not a thoroughly researched peer-reviewed study. These tests were conducted by a working, professional electrical engineer and a seasoned ski guide. Our data is too limited to give any hard numbers or definitive statements. Having said this, we do believe we have done enough testing to begin to identify emerging patterns and apply this to potential search and rescue strategies. We hope this work leads to a better understanding of the problem and initiates more research for search and rescue applications.

Barryvox recorded a distance of 31- 33m and the DSP reported distances of 36-39 m. When devices of potential interference were introduced, they either had no immediate effect or the display indicated an altered distance to the transmitter. When interference became more pronounced the arrow indicating the location of the transmitter began to shift. Additional interference would produce erratic signal locations and variable distances. At this point it was not possible to use the receiver to ascertain the distance or direction from which to search. Further interference resulted in the loss of signal and no distance being reported by the receivers.

The Results When the interference sources were at a distance of 30 cm or greater, none of the sources-excluding the drill-had any significant impact on the distance readings when the receiver's antenna was aligned with the transmitter 's antenna. Rotating the transmitter 90° weakened the received signal, causing the distance readings to increase and show greater variability and, in a couple of cases, resulted in a loss of signal. As the distance of the interferer was decreased, the variability of the distance readings increased and, in some cases, resulted in loss of signal. Generally, the impact of the interference source was greater when the transmitter was rotated 90° due to the weaker signal.

Sources of Interference We gathered three transceivers and an arrangement of electronic devices to test. The transmitting transceiver was a BCA Tracker 2. It was placed on the ground 20m away from the receiving transceiver, which was on a wooden platform about one metre off the ground. The poles of the antennae were aligned pole-to-pole for the first test. The interference was measured indirectly by recording the distance reported by the receiver (actually the range of readings, since they always fluc tuated) and comparing it to the baseline with no interference. Once interference from all devices was measured, the transmitter's antenna was re­oriented to be perpendicular to the receiving antenna and the test was repeated. Each potential source of interference was placed at a right angle from the receiving antenna at 30, 20, and 10 centimetres away, and then in contact with the receiver. Two different receivers were tested, the Mammut Barryvox and the Pieps DSP. Figures 1 and 2 provide a graphical summary of the interference recorded by each device. Each sub-plot indicates the distance reading indicated on the receivers when the source of interference was placed at each distance from the receiver. The amount of interference was inferred by comparing the distance readings to the baseline for the test. Any change in distance, direction, or variability was taken to imply interference. The test was conducted at the Banff airfield; no other potential sources of interference could be found in the area. First, we recorded the baseline distance for each receiving transceiver. At 20 m, with the antennae aligned,the baseline for the Mammut Barryvox varied slightly with a signal of 24-25 m, while the DSP signal fluctuated between 20- 24 m . When the transmitting antenna was aligned perpendicular to the receiver, the Mammut

The greatest interference was recorded by electric motors. The cordless drill we tested rendered receivers useless when it was 50cm from them. The auto-focus motors on the cameras were also quite disruptive, but because of the short duration to focus, we were unable to accurately determine their effect. Though not part of this test, the magneto on a running snowmobile may also be a major source of interference. Display screens appeared to be the second greatest source of receiver interference. We suspect this is caused by the display electronics that is present in all smart phones and tablets.The larger the screen, the greater the interference. LED lights were also a significant source of interference. Just like display screens, LED lights have a refresh (flicker) rate that generates interference. The level of interference was greatest when the antennae were perpendicular to each other. Potential sources of interference needed to be more than 30 cm from the receiver to pick up a clean signal 20 m away. Another surprise was how significantly foil impacted the receiver in a search. When a small square of aluminum foil was placed over or under the receivers, the effectiveness of both units was seriously degraded. Foil is an avalanche transceiver's kryptonite. Foil did not have a major impact on transmitters unless the unit was literally wrapped in foil. An interesting result in Figures 1 and 2 is that the interference produced by an iPhone was similar when airplane mode was enabled and disabled. In both cases, the display was on. This ruled out the cellular, WiFi, or Bluetooth links as the interference source. The likely source was either the display driver or the switching regulator used to power the display. Both of these types


Figure 1: Interference with Barryvox transceiver.

Figure 2: Interference with Pieps transceiver.

of circuits switch currents on and off rapidly and therefore can produce electro-magnetic interference (EMI) across a broad frequency range. Similarly, the LED headlamps use pulse width modulation (PWM), where the current is rapidly switched on and off with a variable duty cycle to control the power delivered to the LEDs; this can produce wideband EMI. Electric gloves and boots also use PWM to control heat level. Looking across all the interference sources tested, it is unlikely that any of them produce a strong interfering signal directlyat the 457kHz transmit frequency used by the beacons. So why does the LED headlamp or an active display cause interference? The likely culprit is saturation, or overloading of the beacon's receiver analog circuitry prior to the digital signal processor (DSP) that is used to isolate the 457kHz tone. To understand this, one must look at how a digital transceiver


processes an analog signal. Before the DSP can process the signal, it must be digitized-the analog voltage coming from the antenna must be converted to numbers the microprocessor can manipulate. The very weak received signal will be amplified, mixed, and filtered by the front-end circuitry, but with lower selectivity than possible with the DSP. If a strong interfering signal is present alongside the weak received signal, it can cause the amplified signal to become saturated. The weak signal is effectively lost. Even before saturation occurs, thestrong interferer will reduce the amount of amplification that can be applied to the weak signal.This reduces the resolution with which the weak signal can be digitized and results in increased variability of the reported distance. The problem of interference is therefore likely one of broadband EMI overloading the signal processing circuitry of the receiver

before the desired 457kHz signal can be extracted. Any circuit that switches rapidly can produce broadband EMI. The higher the voltage or current being switched,the greater the strength of the EMI. The frequency contentof the EMI depends on how fast the circuit switches,with faster switching producing higher frequency EMI. A cell phone transmits its signal in the GHz (GHz= billion Hz) range, well above the filter bandwidth of the beacon's receiver, so it is unlikely to cause interference. The switching regulator used to power the display may operate in the l 00's of kHz (kHz= thousand Hz) range and can therefore produce EMI that is within the vulnerable frequency region for the avalanche transceiver. One saving grace of many of these EMI sources is that since they are not purposeful transmitters of signals, their effective antennas are poor and the transmitted power is low and therefore weakens rapidly with distance . It should be noted that this discussion of how interference may impact the receiver is based on general engineering principles applied to similar circuits. We do not have specific knowledge of the circuit design of the transceivers that were tested. We included a cordless drill in our interference source because the high power PWM circuits used to drive the brushless motor can be a fantastic source of broadband EMI. As seen in the results, the operating drill causes a loss of signal if it is anywhere near the receiver. With the above discussion in mind, the counter-intuitive result of relatively low interference of the VHF radio, a powerful radio transmitter, makes sense. The VHF frequency band is 30-300MHz (MHz= million Hz) and lies far above the avalanche receiver's bandwidth. Therefore, the radio signal can be filtered out by the receiver's front-endfilter. The iCom radio also has a simple LCD display that does not need a high-power switching regulator or display driver, therefore it produces lower levels of EMI and, hence, less interference. One unexpected result was the impact of aluminum foil on both the transmitter and receiver. Due to the long wavelength (-650m) of the 457kHzbeacon signal and the small antenna that is used, the signal is predominantly transmitted in the magnetic domain [S] . Non-ferrous material such as aluminum foil should be largely

invisible to it, yet when either the transmitter or receiver were placed on top of a square of foil, it caused the reported distance to vary. When the transmitting beacon was covered or placed on top of foil, the distance readings reported by the receiver showed little change from the baseline distance readings . When the transmitting beacon was placed between the two layers of foil in a clamshell configuration, the distance readings showed significant impact. Placing the beacon in its holster reduced the impact of the foil clamshell somewhat, possibly due to the increased distance between the beacon antenna/circuitry and the foil. It is harder to repeat this experiment on the receiver since the foil obscures the display in many of the configurations. A general observation was that if the foil was placed very close to the receiver, the distance readings increased in value and variability. Based on these results, concerns such as the impact of a foilwrapped energy bar in a pocket near a transmitting beacon are likely not significant. Most skiers will not wrap their beacons in foil, so the significant degradation with a clamshell configuration is not of practical significance. It is unclear what impact clothing with heat reflective foil layers, such as gloves, may have. This is likely mostly of concern when handling the search beacon (receiver) with such gloves.

Mitigating Interference When looking at transmitter interference, all but one source of interference made almost no difference when placed within 30 cm of the transmitter. When the strongest source of interference, the operating cordless drill, was placed close to the transmitter, a normal search was not possible. Based on this, low to moderate interference does not appear to threaten the effectiveness of the transmitter. Strong interference severely impacts the effectiveness of the transmitter. Receivers are a different beast. Searchers need to be aware of potential sources of interference and make reasonable efforts to

Ivars Finvers tests various search strategies with a receiver experiencing moderate interference - an LED headlamp, a GPS unit and a VHF radio all within 10 cm of the unit.


Conclusion We hope that this is enough information to begin finding a meaningful understanding of avalanche transceiver interference and possible solutions in an emergency. One day at the Banff airfield is insufficient to solve the problem,but maybe it can start to show us the way forward. For the victim, low to moderate interference near the transmitter does not appear to significantly impact a transceiver search. High levels of interference may crush the effective range of the unit and render the directional arrows on the receiver useless. This is an unlikely scenario, but is certainly possible in industrial settings and may become a growing concern with electrically heated clothing.

Devices that gave off strong interference - drill, electronic displays.

keep them away from the receiver. Electrically heated and foil-lined gloves can easily be missed and can effectively impair a transceiver search . Electronic displays should be kept more than 30cm from the transceiver or turned off. Headlamps may be necessary for the rescue, but keep them at arm's-length from the receiver. More powerful searchlights should stay out of the searcher's immediate vicinity until the transceiver search is complete. VHF Radioscan be used by the searcher so long as there is some distance maintained between the radio and the receiver. It is useful to understand how to continue a rescue with potential interference. What do we do in a rescue where interference is suspected? Our first reaction would be to check the rescuer's gloves. If they are electrically heated or foil-lined, swap them for a different pair or send a different searcher. If this is not the problem, modify the search pattern. We tested searching with a receiver that was experiencing a moderate level of interference and found a workable solution . Moderate interference was randomly defined as a five watt VHF radio on receive, a GPS unit with anactive display screen, and an LED headlampall within 10 cm of the receiver. Finding a signal on a 40 m grid search was unreliable. Tightening the initial grid search to 20 m did provide a consistent initial contact signal with the transmitter. Once the signal is detected, physically mark the location (with a wand or ski pole). At this point you may attempt a standard search. Don't be surprised if the signal is lost as the direction arrows may be ineffective due to the interference. Return to the reference point (the marked spot) and estimate the best direction to proceed. Ignore the arrows on the receiver and watch the numbers on the unit. Begin a grid search until the signal becomes significantly stronger. Once you feel you have a strong signal (we found 15m or less), return to a standard search. We also attempted to locate a transmitter with a high level of interference. We randomly defined a high level as a running cordless drill, large display screen, GPS unit with display on, and a VHF radio, all within 10cm of the transmitter. Neither a standard search pattern nor a reduced search pattern could reliably detect a signal. By applying a 5m micro-strip search to the area, we were able to locate the transmitter using only the distance numbers and a full grid search. The direction indicated by the arrows was useless. The numbers indicated on the transceiver did not reflect even an approximation of the transmitter 's distance from the receiver. At one meter, the unit recorded a 4 m distance. Having said this, the smallest numbers displayed on the receiver did represent the best place to begin probing and a grid search provided an effective strategy to locate the victim. A heavily polluted signal can still provide valuable search information.


For the rescuers, low to moderate interference can affect the receiver, but appears to be manageable. Keep electric motors and generators well away from the searcher. Display screens and LE lights should remain more than 30 cm from the receiver and only used by the searcher if it is necessary to conduct the signal search. Electrically heated and/or foil lined gloves may impair or ruin a signal search. VHF radios are not a major source of interference. If you suspect that interference is impacting the transceiver search: 1. Tighten the initial search grid to 20m until the signal is acquired. 2. Physically mark the location where the signal is first detected. 3. From the marked location, grid search using only the numbers on the transceiver until you have a strong signal (15m or less) 4. Finish by using a normal induction search. 5. If strong interference is suspected, consider having a second searcher begin a Sm micro-strip search in likely burial locations. 6. Hopefully this information is useful. We look forward to seeing future research develop more effective strategies and a better understanding of transceiver interference.

Acknowledgement I would like to thank Ivars Finvers for his time and expertise in this project. Guides and forecasters have a responsibility to build on the knowledge and experience given to us by our mentors. People like Ivars have no such duty to the avalanche profession. His act of kindness is greatly appreciated and directly benefits our industry.

References 1. Barkhausen, John. "The effect of external interference on avalanche transceiver functionality." Proceedings of the 2012 International Snow Science Workshop. 2012. 2. Meier, Felix. "Electromagnetic compatibility of avalanche transceivers." 3. Miller, Steven CM. "Electromagnetic interference from electronic devices used in the management of type 1 diabetes can impair the performance of an avalanche transceiver in search mode." Wilderness & environmental medicine 26.2 (2015): 232-235. 4. Forrer, D., Muller, K., Dammert, I., & AG, C. A. "The effect of communication equipment on avalanche transceivers." 2018. 5. Hereford J, Edgerly B. "457 kHz electromagnetism and the future of avalanche transceivers." In Proc. !SSW 2000.

Dan Dan Kelly Kelly e d i s t outside ou the of of the . . . x box... o b

Dan Kelly is what happens when you live life outside of the box. When you aren't afraid to try new things and you aren't afraid to take new risks. Dan is seemingly undefinable: entepeneur, designer, Dad, skier, sculptor. His is a life filled with creative prosperity. Where were you born and where did you grow up? I was born in Masterton and I grew up on Homebum Station out near White Rock in southem Wairarapa. When and where did you start skiing? Turoa, 1980. What was your first skiing related employment? Field staff at Craigieburn Valley ski field. What do you do for work now? I have my own alpine tourism operation at the head of Lake Wakatipu [ Mt Larkins; Mountain Hut]. How did that come to be? It took a long time to set up the Mt Larkins operation and it's a long story but here is a summary: The land was initially pastoral lease being Wyuna Station. Initially we got permission to erect a hut on the site for personal use. Then when the property went through tenure review and the land ended up being administered by the Department of Conservation we were able to apply for the concession and lease for Mountain Hut and the ski touring operation.The motivation to own and operate a hut with ski touring was based purely on myself and my lady’s passion for these things.

In the tow shed of the Craigieburn Valley Ski Field in 1982.

How did you get started with working in the ski industry? By getting a job at Craigieburn in 1982 Who were your mentors or inspiration in your career? Steve Ward was a brilliant mentor who inspired me to go forward specialising in snow safety and avalanche control work.Since 1982 what other avalanche education, work, or experience etc did you undertake? When I was in the Craigieburn Range in the early 80s to learn about snow and work in the ski industry. It just so happened that I got a job at Craigieburn in 1982 working as field staff. The only other skiing I had done was at Turoa while I attended Massey University. I was lucky to be able to work alongside Steve Ward being his wingman on avalanche control routes. This led me onward to do an avalanche course that was one of the first comprehensive New Zealand administered courses, run by Ian Owens and Pete Weir, and based at the forestry research institute at Broken River. This changed my life. After two winters at Craigieburn Valley, I went on to do another two winters as custodian/ snow safety at Mt Olympus having taken over from Alan Stratford. Then it was on to Fox Glacier working as a glacier guide for Mike Brown on the lower glacier for two winters. There I began to work with helicopters taking heli hikes on the blue ice and of course I began going up high to the main divide with personal recreational tours from the Pioneer Hut. There followed a switch out of the mountains where I became a clothing designer and then ended up in Queenstown, as designer and production manager for the AJ Hackett group of companies. After moving to Glenorchy and being surrounded by big hills, I was keen to build even further on my previous snow industry experience and keen also to set up a small club field. In 1994 we tried what we called an “Unlimited Run Day “ of heli skiing and this proved to be popular. Next came designing and founding Invincible Snowfields which then led onwards to setting up the Mt. Larkins and Mountain Hut operation. How did you end up living in Glenorchy? in 1992 I heard about a derelict cottage for sale and thought that it would be a suitable place to raise a family with the surrounding big scale, ultimate adventure playground. What is the biggest change in NZ skiing since you started? Equipment, weather patterns and show conditions.


What event in your career has had the biggest influence or impact on you? I was in my first year being the rookie assistant to Steve. He said we should dig a pit on Hamilton Face just off the shoulder where skiers would traverse to, then drop in onto the face proper even though they knew we had it closed. At the time there was a lot of snow (August of 1982). The middle basin had already released with huge debris heaps blocking the road. I had been clearing a roadway with the Ford County and there were debris walls three to four metres high or more as you drove through. It was about three-thirty in the afternoon and Steve was not too keen to venture out far off the shoulder onto Hamilton Face proper so we just skied out a bit then dug a pit. The pit ended up being over two metres deep and the column just collapsed on itself of course being so deep. On the bottom of the pit was just free running loose sugary snow. We carefully made our way off the slope. We went to the top tow shed and made up hand charges meanwhile communicating that we would be blasting Hamilton Face after the ski field was shut and everybody was off of the mountain. Back up to the slope we went. I belayed steve out onto the face until he got to a lone big rock and a safe zone. Then he untied and went out further laying two charges, lighting their fuses and getting back to be in the lee of the lone rock where he had set up a sling anchor to clip into. About a minute went by with me watching from the safety of the shoulder. I could see Steve was ok and safely at the rock. BOOM! Nothing happened for a few seconds and we were watching to see where the propagating fracture would be and what was going to happen…what happened was that the whole slope fractured to the summit and right across to the saddle towards Broken River - everything went! Now up until this point I had never heard Steve swear but on the radio all I could hear was the F-word over and over again as he was completely underneath the massive slide. The whole slope appeared to move in slow motion at first then it became more organised and was separating into huge blocks of stiff snow that looked to be as big as houses jostling and pouring down the main face going airborne out over Fourth, Fifth and Sixth Guts. Steve was ok as the rock held firm even though the forces on it were mega. The avalanche went on down the main gully and took out the bottom rope tow and then continued on, way down the valley, creating a new smash line in the previous avo path through the forest margins. The field was shut after that as the access tower was munted. This is why when you go up the access tow now, there is an angle in the tow line.The crown wall of that slide was two to three metres high across. The whole face and the entire snowpack slid to the ground. This avalanche was, for me, the most important thing to have seen as a rookie wannabe snow-man; to fully understand the devastation caused by a big slide.

…what happened was that the whole slope fractured to the summit and right across to the saddle towards Broken River everything went!

Opening day for the Invincibles Ski Field.


What would you tell someone starting out in the snow/avalanche world today? That the topic is very serious. There is an enormous amount to learn. You have to pay attention 24/7 to what is going on in the snow pack. It is not an exact science. Even when you think you know a lot you may still be taken out.

What about a piece would bring out theses deeper emotions in you? When I am making sculptures I am only ever really making them for myself. Sounds silly but I become attached… actually becoming the thing that I am making. I know this sounds weird but it's quite special.

What gives you the most satisfaction in your work? On my watch so far no one has suffered serious injury or loss of life.

What's the next step for your artwork? I am always striving to improve the emotional outcomes of my art. I want viewers of the sculptures to be drawn to them in the same way I am. It's kind of like playing God - making things that aren't alive but somehow giving them life.

If you couldn't work in the ski industry anymore, what would you do? Make sculptures. What medium do you commonly work with? Rusty steel. If you offered me a gold nugget or a rusty bit of a steel I would choose the steel. Did you have previous experience with steel work or metal work? I started out using brass and copper with acetyl oxy welding doing reaturant or bar fit outs and 3D signage. Next came arc welding with steel as it was faster and used recylced materials. How much time do you spend on a given art piece? One to two months per piece. What inspires you in your artwork? Sometimes the artworks can make you cry.

Do you work mostly on commission? I wish I could do more retail work but I keep fully busy with commissions. It’s quite a good problem to have! Where have your sculptures ended up on display? Mostly they are privately owned. Fortunately many owners are happy to install works where the public can view as well. How do you know when you are done with a piece? When it presents correctly in total 3D. Are you aiming for purely accurate/realistic outcomes in your work, or is it something else? With the birds it is definitely to strive to make them accurate in order that the sculptures can convey emotion but I do ramp up some of their features because I can.

Alpine chic. The view from the inside of the Mountain Hut on Mt Larkins near Glenorchy.

What brings you the most happiness in life? Feeling that I can use my body, do things, think things. Sitting quietly in the sun.

What is the biggest challenge facing the NZ skiing industry currently? Same old story: Snow levels, snow conditions.

What has been your favorite make and model of ski? I had a pair of short, thin and whippy pair of Atomic telemark skis once. Even carrying a big pack these things would carve like a hot knife through butter, never really floating up and down just wickedly taking you down. Man they were good.

How do you prepare for the start of a winter season? Pay attention to the frost periods and the first snowfalls.

What is a piece of skiing equipment that you cannot live without? A tiny heavy steel shovel. I can cut steps in blue ice with this. When the going gets tough this shovel is my get out of jail free card.


Have you noticed any particular trends in the NZ snowpack over your career? True powder exists for shorter times now. Have you noticed any particular trends in the NZ snow climate over your career? Inversions increasingly follow cold fronts meaning rain occurs on fresh pow.

When I am making sculptures I am only ever really making them for myself. Sounds silly but I become attached… actually becoming the thing that I am making. I know this sounds weird but it's quite special.


What do you do in the off-season? Mountain Hut is a year-round operation with hiking and mountain biking concessions as well. Visitors stay, climb up to the summit and can hike or bike out. A neat trip becoming popular is to heli to the hut with the bikes on the racks and on the way up we drop the bikes on mt alaska at 1500 m then move on to land at the hut. Guests then hike up to the summit of Larkins, stay the night and the next day pack up the hut and then hike across Larkins Slip to meet their bikes and bike out the rest of the way. Can you please describe an adventure trip with a close call / learning event that sticks out to you? On many adventure trips there have been close calls. Obviously my time to go has not happened yet. One time I was with Dave Crow, a fellow glacier guide at Fox and we had choppered into west Hoe Pass after work then ski toured across to stay at the Pioneer Hut. The next morning we were heading out and down to the Chancellor then down and across Victoria Flats and out the lower glacier to Fox for work. We left the Pioneer Hut early at dawn and skied down the main glacier until we got to the area called The Trough. Here we had to take off our skis and climb up the sidewall before descending to the Chancellor Hut. To save time I suggested to Dave that we not fix crampons on, let's just kick up in our boots. As I was ok about doing this in my leather telemark boots, I figured he should be fine in his plastic ski boots. Off we went up a slope of about forty degrees. Getting near the top of the slope I was aware that I had better super focus on not losing my footing here so I really focussed and made it ok over the lip. I remember thinking that I really hoped Dave would be super focussed at this point too so I looked around for Dave. He was nowhere to be seen. I called out and began moving up and down the lip looking for evidence of his marks. There were none. Oh man, I couldn't believe it and so started yelling, “Dave! Dave!” I soon heard this super faint response and it was like: Wow! He's alive! Where is he? He had slipped on going up over the lip and slid down the slope and shot straight into the main glacier down a black crevasse. The glacier is most likely 1000 feet deep or more here. Not far into the black hole he had slammed into a stalactite and arrested his fall. I went down and threw a rope into the hole and soon we had him out. It was actually Dave's lucky day as later on in the trip as we were making our way through an icefall beneath Victoria, he had stopped to adjust his pack. It was only about two seconds later a ten ton serac crashed onto the exact spot as he was walking away.


Can you describe a "favourite day" of work? One event we organised was a 2 day heli ski session with people tenting out overnight. There was a ton of wood slung up to the site and we had a bonfire on the snow. The fire made its way down into the Snowpack and the late night owls dug steps down and into the deep crater and made Show couches and reclined by the embers with “dooshdoosh” music above and the stars moving across the sky. How has the Covid 19 pandemic affected your work? Significantly, but a lot of great Kiwis are still coming and going up to the hut. Mountain Hut is still operational with only Kiwi visitors. The operation is geared for low numbers and no real fiscal or operational challenges have occurred during the last two years. There are reasonable amounts of hut visitors, bikers and hikers and ski touring bookings for 2022 are solid, as was the turnover in 2021. People find out about Mountain Hut by word of mouth and through our website ( Many guests return year in and year out. What (if any) "Golden Rule" (or rules) guide you in your work or life? Take the time to do things properly. Pay attention to the smallest details.


Keeping An Eye On

MODIS images from June 22 2015 showing the North and South Islands of New Zealand on a mostly cloud free day.


Snow From Space Todd Redpath School of Geography & School of Surveying Mountain Research Centre University of Otago

THE SOUTHERN ALPS are vast. The land area above 1200 m in the South Island is approximately 22,000 square kilometres, or 15% of the total land area. Whether you’re ski touring recreationally, guiding clients, or looking to get a handle on the current snowline elevation for avalanche forecasting, that’s a lot of terrain to explore in a “normal” snow year. Some of us can see what the snowline is doing with a glance out the window, while for others a view of the mountains is a long drive or a flight away. Webcams and weather stations provide useful remote observations, but only provide a limited view of conditions. Nowadays, however, it is relatively easy to complement these observations with a view from space. We commonly refer to the science of looking back and observing Earth from space as remote sensing.


Since the year 2000 there has been a massive increase in earth observation (EO) satellites. These are satellites that orbit Earth at an altitude of 500 – 700 km and carry sensors designed to continuously image Earth’s surface. Such satellites have been a game changer for the scientific study of seasonal snow (for New Zealand examples see Sirguey et al., 2009 and Redpath et al., 2019). Best of all, much of the data these satellites capture are available freely and increasingly easily accessible online. This article is intended to provide a brief introduction to using imagery from EO satellites for looking at snow and avalanches. The focus is on three satellite sensors in particular: Sentinel-2, MODIS and VIIRS. The imagery described here is collected passively, relying on recording sunlight that is reflected from Earth. There are many more satellites and sensors out there though, so consider this the tip of the iceberg.

How do satellites “see” snow? As humans, we have evolved a vision system that is sensitive to light between wavelengths of 3.8 and 7.4 micrometres (a micrometre, µm, is a millionth of a metre). Usefully, this range of wavelengths, which we can refer to as the visible part of the electromagnetic spectrum, is coincident with the bulk of energy that reaches the Earth’s surface from the sun. Less usefully, if we were to look back at Earth from space, we would notice that it is usually difficult, if not impossible, to distinguish cloud from snow when we are limited to perceiving visible light. Fortunately, all is not lost, because: 1. The sun emits, and Earth reflects, energy at wavelengths beyond the visible spectrum, and 2. We can design and build instruments that are sensitive to these wavelengths and capable of recording them in an image that we can display on screen (or print!), much like a digital photograph, and 3. At wavelengths outside of the visible spectrum, the interactions of clouds and snow with incident light begin to diverge. Importantly, snow tends to become less reflective as the wavelength of light increases, and the proportion of light that is reflected is influenced by grain size (see Figure 1). This article describes multispectral imagery, from optical sensors. By recording reflected energy across specific regions of the electromagnetic spectrum, we can resolve the “spectral signatures” of targets on Earth (Figure 1) and classify image pixels according to their spectral characteristics (or, how they look in an image). This can be done systematically, something computers are very good at, or qualitatively, by looking at the image ourselves (we’ll call this visual interpretation). In this article, the focus will be assessing snow cover. Mapping snow depth from space is a bigger challenge, but one where ongoing research (including by members of the Mountain Research Centre at Otago) is making substantial progress.

Understanding Satellite Imagery Satellite imagery is usually described in terms of its resolution. Resolution tells us how much information the imagery contains. Three important elements of resolution are: Spatial resolution is the difference in being able to spot your car in your driveway or struggling to make out your house in Google Maps. It is determined by the area on the Earth’s surface that is sampled by each image pixel. EO sensor spatial resolution ranges from 30 cm (each square pixel of the image is 30 30 cm) to 1000 m (each square pixel of the image is 1000 1000 m). Freely available satellite imagery tends to have a spatial resolution on the order of metres, to tens, to hundreds of metres.


Figure 1: The reflectance of snow, of varying grain size, as a function of the wavelength of incident electromagnetic energy, or its "spectral signature". The visible portion of the electromagnetic spectrum is indicated by the coloured regions labelled V (violet), B (blue), C (cyan), G (green), Y (yellow), O (orange) and R (red). Digital cameras, and the imaging sensors aboard satellites tend to be sensitive in the blue, green and red regions. Also shown in the plot are the nearinfrared (NIR) and short-wave infrared (SWIR) regions. At these longer wavelengths, the reflectance of snow decreases as grain size increases, and is diminished compared to clouds. Spectral profile data from the ECOSTRESS Spectral Library (Meerdink et al., 2019;

Spectral resolution relates to how many “bands” an image has. Each band is acquired by recording energy (light) within a specific region of the electromagnetic spectrum. A regular digital camera records light across red, green, and blue portions of the spectrum in separate bands. Stacking these three bands on top of each other reproduces most of the colours perceived by humans. The imaging sensors carried aboard satellites often have multiple bands ranging from visible through to near (NIR) and short-wave infrared (SWIR) regions (Figure 1). More bands provide improved spectral resolution. For observing snow, we really want imagery that includes NIR and SWIR bands. Note that we can only display three bands at a time on a digital display. Temporal resolution tells us how often we image the same region on the Earth’s surface with the same sensor and is primarily controlled by the orbit of the satellite and the width of the image footprint (swath width) at the Earth’s surface. EO satellites usually orbit close to the polar axis as Earth rotates below, therefore the region of Earth visible to the satellite is constantly changing. Most EO satellites complete an orbit in around 100 minutes, combined with the swath width of a particular sensor this provides temporal resolutions ranging from daily (high) to twoweekly or longer (low). Increasingly, the temporal resolution is increased by using a constellation of satellites carrying the same sensor in offset orbits. Optimising resolution across these three characteristics is challenging and expensive, so compromise is inevitable. The MODerate resolution Imaging Spectroradiometer (MODIS), which is operated by NASA and carried aboard the Terra and Aqua Satellites, for example, captures imagery over New Zealand twice daily, with high spectral resolution, but relatively low spatial resolution (ranging from 250 m to 1000 m). Conversely, the ESA run Sentinel-2 mission provides imagery with a spatial resolution of 10 m to 60 m, and good spectral resolution (visible, NIR and SWIR). The temporal resolution for a single Sentinel-2 satellite, however, is ten days for most regions. Operating a constellation of two satellites reduces this to five days. Over New Zealand (and other higher latitude locations) Sentinel-2 imagery can be captured as often as every three days due to overlap of the image swath.

How can you explore these data? Sentinel Playground by Sentinel Hub Sentinel Playground, a component of Sentinel Hub and developed by the Slovenian company Sinergise, is an interactive web map environment that allows users to access archived imagery from different sensors aboard several satellite platforms. It is particularly useful for exploring Sentinel-2 imagery. Launched in 2015 (Sentinel-2a) and 2017 (Sentinel-2b), the Sentinel-2 satellites image the Earth’s surface across 13 spectral bands (you can find more information about Sentinel-2 here: can access Sentinel Hub at, while more information can be found at

Figure 2: Sentinel Playground showing Natural Color Sentinel-2 imagery and key features.

Sentinel Playground provides several options for navigating the map and adjusting the display. The Search box can be used to search for specific geographic locations (for the example Mount Pisa in Figure 2). The Rendering button opens a panel within which you can change the way the imagery is displayed, by choosing a particular band combination, or derived index. Figure 2 shows Natural colour, where the blue, green and red bands of the image are displayed. Next to the Rendering button is the Effects button, clicking on this allows you to adjust the contrast of the imagery using the Gain slider, and to add image dates as annotations to the map view. Imagery can be selected from the Sentinel-2 archive for any available date using the Calendar. Days with imagery are indicated with a circle. A light grey circle indicates that cloud cover is less than the currently set threshold, otherwise the circle will be dark grey. The cloud cover threshold can be adjusted using a slider accessed by clicking the button next to the calendar - 20% is a good starting point. Note that the dates in Sentinel Playground are in UTC, so are a day behind NZST! Dates used in the text here have been converted to NZST. Dataset selection allows you to choose which data you see in the map view. There are several choices, but we will focus on two: Sentinel-2 L1C: Sentinel-2 imagery provided at the L1C level of correction, which means the imagery is geometrically corrected, but not corrected for atmospheric effects. This means the image contrast is often reduced, but generally still sufficient for visual interpretation. The examples here use L1C imagery. Sentinel-2 L2A: Sentinel-2 imagery provided at the L2A level of correction, which includes geometric and atmospheric correction. While this improves contrast, it can also result in artefacts that can complicate visual interpretation of imagery. As you can see in Figure 2, despite the intuitive appearance of the Natural color band combination, distinguishing between snow and cloud is barely possible.


This is where those extra spectral bands start to become useful. Figure 3 shows a false-colour composite, the Color infrared (vegetation) rendering. This combination sees the NIR band of the image displayed using the red channel of the screen, the red band of the image displayed with the green channel of the screen, and the green band of the image displayed with the blue channel of the screen. Vegetation now appears in red to pink tones, because it is much more reflective of near-infrared light than red or green. The enhancement of vegetation can be useful for interpreting what is happening close to the snowline and assessing patchy and thin snow cover. Distinguishing snow from cloud, however, remains difficult. Figure 4 again shows a false-colour composite, this time the blue band of the Sentinel-2 image is displayed as red, and the two SWIR bands are displayed green and blue. Now vegetation appears green, water appears dark, and snow appears in red to pink tones. Clouds appear across the range of white to orange to pink tones, depending on their composition, but we also gain sufficient contrast

to resolve their distinctive texture. Between variations in colour and texture, snow and cloud can now be distinguished from each other. Note that the SWIR bands have a spatial resolution of 20 m. Zooming in on this band combination won’t reveal as much detail as for band combinations using the red, green, blue and NIR bands, which have a spatial resolution of 10 m. Clicking the following links will open Sentinel Playground within a web browser at a specific location and date of interest. Firstly, an example of detecting avalanche debris that extends below the snowline, with both NIR and SWIR false-colour composite images: Avalanche debris example 1: NIR; Avalanche debris example 2: SWIR. Because the snowline in New Zealand tends to be above the valley floor, detecting big events on major paths can be relatively straight-forward, if we get a good cloud-free view. Scrolling through dates using the calendar can help narrow down the window of occurrence. Now, an example using a public observation submitted to

Figure 3: Sentinel Playground showing Color infrared (vegetation), or NIR false-colour composite, Sentinel-2 imagery.

Figure 4: Sentinel Playground showing SWIR-2,11,12, or SWIR false-colour composite, Sentinel-2 imagery.


Figure 5: NASA Worldview showing Corrected Reflectance (True Color) imagery from MODIS (Terra). (Avalanche example - public observation). This size 4 avalanche occurred sometime prior to October 15, 2020. On October 19 Sentinel-2 captured a clear view: Avalanche example: NIR, note the subtle blue tone of the avalanche debris in the NIR false-colour composite. This is likely due to an increased grain size (and possibly increased liquid water content) of the avalanche debris which in turn reduces the near-infrared reflectance relative to the surrounding snow. The SWIR false-colour composite (Avalanche example: SWIR) provides good contrast between snowcovered and snow-free pixels.

Worldview by NASA Worldview (, with further information available at is a feature and data rich web mapping environment that provides access to several products that are useful for assessing snow cover. Worldview is particularly useful for exploring data from MODIS, which is displayed in True Color (equivalent to Natural color in Sentinel Playground) by default when the app is launched (Figure 5). MODIS provides a relatively long record of daily satellite imagery for New Zealand, with imagery captured from Terra in the morning and Aqua in the early afternoon. Imagery appears on Worldview within a few hours of acquisition. The high temporal resolution comes with the trade-off of low spatial resolution (at best 250 m in this case). While the spatial detail provided by MODIS is limited compared to Sentinel-2, it is very useful for assessing the extent of snow cover or estimating snowline elevation at regional scales. The South Island snow cover graphs and maps at modis-snow-cover come from MODIS data. Different satellite imagery products can be turned on and off in the Base Layers section of the right-hand side panel (click on the “eye” icon). Switching between morning (Terra) and afternoon (Aqua) imagery can give an idea of rapid melt as snow cover diminishes following low-level snow fall events or during warm conditions. The time controls are in the lower part of the window, where you can scroll using the time slider, enter a specific date, or increment by year, month, or day.

The SWIR false-colour composite we explored previously with Sentinel-2 is also available for MODIS, but only from the Terra satellite, due to problems with one of the SWIR bands on Aqua/MODIS. To add it to the map, click on the + Add Layers button and search for “367” in the pop-up window, select Corrected Reflectance (Bands 3-6-7). Close the pop-up and you’ll see the image added to the map and be able to distinguish between cloud and snow (Figure 6). The satellites carrying the MODIS sensor are approaching the end of their missions. Fortunately, imagery from the newer Visible Infrared Imaging Radiometer Suite (VIIRS), which is captured daily and comparable to MODIS, is also available in Worldview. VIIRS Corrected Reflectance (True Color) imagery is an available Base Layer from both the NOAA-20 and Suomi NPP satellites when Worldview first loads. Searching “M3-I3-M11” in the Add Layers window will allow you to add VIIRS SWIR false-colour composites from both Suomi NPP and NOAA-20, as we did previously for MODIS imagery from Terra. A nice feature of Worldview is the ability to quickly compare snow cover at a specific time in the season by changing the year in the date controls. For scientists studying seasonal snow, MODIS and VIIRS are important data sources for assessing snow cover variability and trends in time and space. More information on MODIS is available at, and VIIRS at

This is cool, I want more! Awesome! There is a huge volume of data available out there to be explored. If you want to dig into this further, I’d recommend exploring the SentinelHub EO Browser ( This tool is similar to Sentinel Playground, but more feature rich and includes measurement, 3D visualisation and timelapse tools, as well as providing image download functionality if you’re a GIS user. The EO Browser web page includes helpful resources to get you started. I can only thoroughly encourage you to play around with these tools and see how they might fit into your approach to assessing conditions, either professionally or recreationally.


Figure 6: NASA Worldview showing Corrected Reflectance (Bands 3-6-7), or SWIR false-colour composite, imagery from MODIS (Terra).

Within the Mountain Research Centre (MRC) at the University of Otago, remote sensing tools are central to many of our research projects. We are keen to help build capability in working with satellite imagery amongst the snow and avalanche community, and to get feedback on specific questions or problems relevant to alpine professionals in New Zealand. If the appetite exists, there is scope to further explore what has been covered in this article via interactive workshops. If this is something you’d like to know more about, or you have any other questions or ideas please don’t hesitate to get in touch! Also keep an eye on this and future editions of NZAD for updates on our snow, glacier, and alpine focused research projects.

References Meerdink, S.K., Hook, S.J., Roberts, D.A. and Abbott, E.A., 2019. The ECOSTRESS spectral library version 1.0. Remote Sensing of Environment, 230, p.111196, Redpath, T.A.N., Sirguey, P. and Cullen, N.J., 2019. Characterising spatio-temporal variability in seasonal snow cover at a regional scale from MODIS data: the Clutha Catchment, New Zealand. Hydrology and Earth System Sciences, 23(8), pp.3189-3217, Sirguey, P., Mathieu, R. and Arnaud, Y., 2009. Subpixel monitoring of the seasonal snow cover with MODIS at 250 m spatial resolution in the Southern Alps of New Zealand: Methodology and accuracy assessment. Remote Sensing of Environment, 113(1), pp.160-181,


Fatal Accident on Avalanche Peak THE NEW ZEALAND ALPINE JOURNAL Vol. V. JUNE, 1934 No. 21

Arthurs Pass ON July 30, 1933, the Railway Department ran to Arthurs Pass one of its Sunday excursion trips, which are widely used by Canterbury climbers to snatch a day’s climbing in winter conditions. On this particular day, on arrival of the train, a party of 30 to 40 set out for Avalanche Peak. This peak in summer time is free from snow, but in winter is covered nearly to bush level. On the climb to bush line, the party was thinned out, and those left were generally fit and properly equipped lo carry on the climb. They included representatives of three clubs and some unattached excursionists. There was no organised party and no one definitely in charge. No accurate count was made of the numbers continuing the climb, which was believed to be 18. It was in fact 19. There was a heavy nor’-wester blowing though the weather was fine. S. E. Russell was amongst those who went on. One member led kicking steps and the others followed in single file, the route being along the ridge until the lower peak was reached. Here the wind was very bad, and the driven snow made conditions so unpleasant that the party left the ridge and descended in a group into the basin between the two ridges. From here the ascent was continued again in single file directly up the face of the peak. The snow was soft on top, but firm underneath. When about 200 feet from the top, the snow broke just ahead of the leader and the whole party, except one or two in the rear who had time to get clear, was carried down until the snow came to rest in the basin about 450 feet below. The avalanche was about 90 feet wide at its base and about 8 feet deep. A few minor injuries were sustained, but all were able to descend without assistance. After the members of the party had extricated themselves, a count was made by one of the party who said he had made a count at bush line and all were satisfied that the whole party was intact. A search was made as a precautionary measure and also in an attempt to find a number of missing iceaxes. On the train returning to Christchurch, it was discovered that Russell was missing. Next day a search party of 14 reached the spot, but were driven back by bad weather. On August 6, another search party under Alf Brustad was able to begin digging operations, though since the day of the accident a further three feet of snow had fallen. The body was

Canterbury climbers would have used trains such as this to make there way to Arthur's Pass for outings

found at the end of the avalanche. Such briefly are the facts of the death of Samuel Edgar Russell, already at the age of 23 a Master of Arts and beforewas just opening the prospect of a brilliant career. To his parents and to his brother, a subscriber of the New Zealand Alpine Club, we tender our deepest sympathy. Mr. G. E. Mannering, who assisted in the search party, writes as follows: The accident occurred in a corrie—a crescentshaped hollow in the face of the mountain—which is flanked on either side by rounded ridges leading to the summit. It is obvious that snow accumulates in the central part of the corrie, being drifted, in by the wind from either the north-west or south-west. The upper part of the corrie contains several steep couloirs or depressions between the rocks which carry the drainage from the upper part of the mountain. At the foot of the corrie lies a shallow basin, which receives! any avalanche snow which may come down. The rise of the slope from the summit ridge to this basin might be a matter of 500 feet in altitude—as a rough estimate. The snow lies at an approximate angle of 35°, though the angle decreases as the basin is approached from above. At the upper part of the excavation, when digging for Russell's body, I measured the angle with a clinometer and found it to be 29°.



During north-west weather, especially if rain were falling at from 5,000 to 6,000 feet, the snow in this corrie would always be in readiness to generate avalanches, particularly if a later fall were lying on an old hard surface of a previous fall. The tendency to come away would also doubtless be assisted by water seepage from the rocks above. Climbing in the corrie under such conditions would be highly dangerous. The wise course for climbers to take would be the ridge on either side. The corrie would be perfectly safe after a fresh snowfall provided there were a good crust on the newly fallen snow, and provided that snow were still in a crystalline state and had not become heavy and partly viscous or fluid with moisture as it does in nor’-west weather.

When the search party was working on the slope on the Saturday and Sunday, everything was safely frozen up with south-west weather, and it would have been impossible to start an avalanche in the fresh three or four feet of snow which had fallen since the accident. The climbing party ascended the snow in the central part of the corrie to avoid the wind on the ridge route, and, although there may not have been to them indications of dangerous or unstable conditions of the snow in which they were actually climbing, there was great danger from the snow above them, as the avalanche started some distance above the leading man of the party—it was not set going by the party themselves. My belief is that the steep snow in the couloirs above was saturated and heavy with

According to the arrangement with the Justice Department, the Coroner in Christchurch consented to admit expert evidence at the inquest and to add a rider to his verdict in accordance therewith. The rider is as follows: “The evidence satisfies me that: (a) A mountaineering party should always be limited as to numbers, and the individuals comprising the party should be definitely ascertained before the party sets out on its journey. (b) Parties should, where possible, place themselves under the direction and the control of an experienced mountaineer. (c) Parties are recommended to keep to the ridges as far as possible, and should not make use of a couloir or gully if another route is practicable. Note.—To some people the spirit of adventure calls very loudly, and mountaineering with its difficulties and dangers proves an irresistible attraction. Mountaineering Clubs should be encouraged, so that people who desire to indulge in this form of exercise may gradually be educated in mountaineering and may be taught to appreciate and avoid danger. E. D. Mosley, Coroner”

Courtesy: DOC Arthur’s Pass Photo Collection

water, had lost its coherence, and was ready to come down at any moment where the search party were working. These avalanches must have been considerable as their detritus was not fully masked by the three or four feet of new snow which had fallen since the accident. There are many places of this character in the Arthur’s Pass district, there being several on the route by which Mt. Rolleston is usually climbed and where there have been several narrow escapes already. The moral is: " In nor'west weather shun the faces and stick to the ridges.” The following is the report of the Accident Committee of the Federated Mountain Clubs:

The Accident Committee of the F.M.C. welcome this precedent, and would like to supplement the sound recommendation of the Coroner in one or two respects. To Clause (a) we would add that, where a large party is out, it should be divided into independent parties of from four to six each under a responsible leader. Clause (b), we suggest that the words “where possible” should be replaced by the word “ always.” It is the Committee’s opinion that no party should be without an experienced leader. The main moral to be drawn from the accident would seem to be that, for climbing in winter or spring, extra care is necessary because snow conditions are dangerous. We in New Zealand do not yet know much about winter snow conditions, and therefore the greatest care must be taken not to attempt the traverse, or even ascent, of a steep snow slope in winter or spring unless the leader is sure that the angle of slope and condition of the snow justifies the route. Another moral is that parties must not assume that a low or easy peak can be treated with less respect than a higher mountain. All mountains are entitled to respect, and are apt to enforce it if ignored. The lowest peak, under certain conditions, must be treated seriously and every care taken. (Signed) Arthur P. Harper, Chairman. September 26th, 1933.



Ed Anderson

I have been thinking a lot about the word professional lately. I have made my living from skiing and snow for the better part of nearly five decades but it took me a long time before I ever thought of myself as a professional. Some of that may have been the culture I surrounded myself with at the time but mostly I put it down to me and my maturity, or lack thereof.

get into my pow stashes before anyone else. My shit was so dialled: I would get all of my morning work done, get back up the four-seater chairlift, make a quick check in at the duty station then rip as many pow lines as possible before public even got up on the first chair. In my mind the public was the enemy and if they got to “my” lines before I did it was a gut wrenching defeat.

This year my alma mater, the Canadian Avalanche Association (CAA) voted to change their official terminology from avalanche “practitioner” to avalanche “professional”. I think that this revised nomenclature is important and I applaud the CAA for the change. Words are obviously the foundation of proper communication. So is there a difference between someone who “practices” a craft or a skill and someone who professionally applies their skills to a situation? Hell yes there is.

Then there came a day that I remember vividly. I had moved up the patrol food chain a bit and had relatively unchecked freedom to move about the ski area at will. That fateful morning I had finished my control route and I was riding the four-seater back up to the duty station to drop off my extra shots but I was running late. From the chairlift I could see my favourite pow runs being absolutely destroyed by the paying masses. All of my lines that I knew like intimate lovers were seeing the touches and embraces of the filthy Others but instead of gut wrenching envy it made me somewhat excited like some perverted voyeur. In fact I felt very different than I had felt before, I felt pride. Pride for the work I had done to make it safe for everyone to come up and enjoy spending time in the snow (formerly MY snow). I also felt gratitude for the punters because without them I knew I wouldn't get paid.

I grew up in a ski town with multiple ski areas just an hour drive from home. As soon as I was out of university and was thoroughly confused about what I wanted to do next, I went straight to the local ski area for work. Skiing was what I knew. In those early years I found work as a lift operator, lift mechanic, ski instructor, ticket seller, janitor, and even a shuttle driver to name a few, but let’s get one thing straight: I was there to ski. Eventually, I started ski patrolling and from day one I knew that I had found my dream job. I was young, skiing pow all day and then partying all night. I was being paid to live the dream. After a few seasons on patrol, I knew the ski area better than anyone else did. That and I had a free pass to all the terrain and all the powder I could ski: the Red Jacket. At work, I devised cunning systems to place myself right where I needed to be each morning, before the public, in order to

I remember that chairlift ride as the moment that I became a professional. For so many seasons I was at odds with the public but on that chairlift ride I felt liberated. On that chairlift ride I recognised my place in the skiing community. I still fought hard for pristine pow skiing, but occasionally at the top of a slope ready to drop in I’d stop, wait a couple minutes for some guests to catch up, turn to them smiling and say “Why don't you go first.” It was the professional thing to do.


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