RTP NSBE JR - Th Voyagers - The Impact of and Recovery from Earthquakes (Paper)

Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES The Impact Of and Recovery from Earthquakes

By The Voyagers Jonathan Winstead II Daniel Ezeogu Nana Duodu Imani Ezeogu

REGION 2 Research Triangle Proteges Chapter NSBE Jr. Raleigh-Durham-Chapel Hill, NC April 2021

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

Abstract

By The Voyagers – Jonathan Winstead II (lead), Nana Duodu, Imani Ezeogu and Daniel Ezeogu Introductory Statement​: Earthquakes are the number one deadliest natural disaster in the world, causing devastation and the crippling of communities and nations. There have been one-hundred twenty-nine reported earthquakes world-wide in the last five years.

An earthquake is a sudden shaking of the earth’s surface, usually resulting in great damage.

Faults are cracks in the earth’s crust and are the boundaries between tectonic plates. When tension builds up along a fault, and then is released, the result is an earthquake. Also, smaller earthquakes, aftershocks that normally occur and continue to occur several weeks after the initial earthquake. They can cause significant damage as well.

There are certain areas in the world that are more susceptible to earthquakes than others, such as those located along the “Ring of Fire.” There are many countries that line the ring of fire, whereas, the countries at high risk of being struck by an earthquake include Chile, Japan, the US west coast, Pacific Islands.

Purpose​: The purpose of this study is to inform of the likely locations, scientific causes, impacts, preparedness, and recovery from an earthquake. Increasing awareness of careers associated with this science will potentially encourage students' interest.

Procedure:​ The team conducted an experiment to study the effects of an earthquake on a structure. The team developed an experiment plan that started with generating structure design ideas.

Next, essential materials, toothpicks and marshmallows, were gathered. Then the shaker table that would simulate the movements of an earthquake was constructed. The team came up with a candidate model that would be tested in the simulation. The team tested the stability of the structure before putting it into the earthquake simulator. Next, the structure was tested on the shaker table simulator. The shaker table simulator consisted of a cardboard shoe box and marbles beneath a layer of cardboard that simulated the tectonic plates. Rubber bands were placed to tie the cardboard platform in the corners. This simulates the movement of the plates and the resistance between the plates.

Data:​ The team is still continuing to evaluate and analyze the most optimal structural design in regards to cost, time and performance. Results are in process.

Conclusion​: The objective is to understand what the team can conceptualize and what can be optimal for different constraints in different environmental scenarios. This is not yet determined. Structural engineers design buildings and structures according to needs. They design and construct buildings to withstand damage from natural disasters, including earthquakes. They work to improve the structural integrity of the existing structures. It is extremely important to understand what earthquakes are and how they affect our society. Earthquakes are powerful and can devastate whole communities, neighborhoods, businesses, grocery stores, libraries and schools. This leaves families homeless and hungry and devastated. The recovery process from an earthquake can take months to years to find housing, food, a stable job, and essentials for restarting.

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

Table of Contents Table of Contents

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INTRODUCTION

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What are Earthquakes?

What is Plate Tectonics Theory?

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How Do Tectonic Plates Move?

The Ring of Fire: What is it?

Why Do Earthquakes Occur Around The Ring Of Fire?

4 5 6

What Should You Do To Prepare For And Recover From An Earthquake?

What Are Structural Engineers and What Do They Do? How Do Structural Engineers Minimize The Damage Done From An Earthquake?

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MATERIALS & METHODS Purpose

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Methodology (Materials and Methods)

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RESULTS

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DISCUSSION

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CONCLUSION

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REFERENCES

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List of Figures Figure 1: Earth’s Surface (Lithosphere Shown) Figure 2: Cracks In The Ocean Floor From Tectonic Plates Moving Figure 3 : Subduction of the Earth’s Crust Figure 4: Location and Names of Tectonic Plates

List of Tables Table 1: Earthquake Magnitude Scale Table 2: Top 5 Largest Recorded Earthquakes Table 3: Building Concepts To Be Tested Table 4: Results and Observations from Vibration Simulations

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

INTRODUCTION What are Earthquakes?

Earthquakes are the number one deadliest natural disaster in the world, causing devastation and the crippling of communities and nations. There have been one-hundred twenty-nine reported earthquakes world-wide in the last five years. An earthquake is a sudden shaking of the earth’s surface, usually resulting in great damage. Faults are cracks in the earth’s crust and occur at the boundaries between tectonic plates. In geologic terms, a tectonic plate is a giant, rigid slab of solid rock in the earth’s surface. When tension builds up along a fault, and then is released, the result is an earthquake. Also, smaller earthquakes, called aftershocks normally occur and continue to occur several weeks after the initial earthquake. Aftershocks can cause significant damage as well. ​[Ref 1]

What is Plate Tectonics Theory?

The theory of plate tectonics was introduced over 30 years ago. Plate tectonics is the theory dealing with the dynamics of the Earth’s outer shell. Earth has a rigid outer layer, known as the lithosphere, which is usually 60 miles thick. ​[See ​Figure 1​]​ The lithosphere is broken up into seven very large continental sized plates. There are also six or seven regional sized plates. These plates move relative to each other, typically at rates of 5 to 10 cm (2 to 4 inches) per year, and interact along their boundaries, where they converge, diverge, or slip past one another. It is believed that these interactions are responsible for most of Earth’s most significant activity. Plate motions cause mountains to rise where plates push together, or converge, and continents to fracture and oceans to form where plates pull apart, or diverge.​[Ref 1] [Ref 2]

Figure 1: Earth’s Surface (Lithosphere Shown)

How Do Tectonic Plates Move?

The Earth’s outer shell is divided into several plates that glide over the mantle, which is the rocky inner layer above the Earth’s inner core. The plates move when hot magma wells up at the ridges, forming new ocean crust and shoving plates apart.​ [See ​Figure 2]​ ​ When they move, hot lava escapes from the mantle. The plates move through a process of one plate moving under another plate thereby causing one of the plates to sink. This process is called subduction. ​[Ref 2] [See ​Figure 3​]

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

Figure 2: Cracks In The Ocean Floor From Tectonic Plates Moving

igure 3 : Subduction of the Earth’s Crust F

The Ring of Fire: What is it?

There are certain areas in the world that are more susceptible to earthquakes than others, such as those located along the “Ring of Fire.” It is called the “Ring of Fire” as this volcano and earthquake activity area forms a shape of a ring. ​Its length is approximately 40,000 kilometers (24,900 miles) long.

The Ring of Fire is the most seismically and volcanically active zone in the world. ​ [Ref 7]​ There are many countries that line the ring of fire and those countries that are at high risk of being struck by an earthquake include Chile, Japan, the US west coast, and the Pacific Islands. Most earthquakes and volcanic eruptions do not strike randomly but occur in specific areas, such as along plate boundaries. One such area is the circum-Pacific ​Ring of Fire,[Ref 4]​ where the Pacific Plate meets many surrounding tectonic plates. ​Seventy-five percent (75%) of Earth’s volcanoes—more than 450 volcanoes—are located along the Ring of Fire. Ninety percent (90%) of Earth’s earthquakes occur along its path, including the planet’s most violent and dramatic seismic events.​[Ref 5]

igure 4: Location and Names of Tectonic Plates F

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

Why Do Earthquakes Occur Around The Ring Of Fire?

The abundance of volcanoes and earthquakes along the Ring of Fire is caused by the amount of movement of tectonic plates in the area. Along much of the Ring of Fire, plates overlap at convergent boundaries called ​subduction zones​. That is, the plate that is underneath is pushed down, or subducted, by the plate above it. As rock is subducted, it melts and becomes magma. The abundance of magma so near to Earth’s surface gives rise to conditions ripe for volcanic activity. A significant exception is the border between the Pacific and North American Plates. This stretch of the Ring of Fire is a ​transform boundary​, where plates move sideways past one another. This type of boundary generates a large number of earthquakes as tension in Earth’s crust builds up and is then released. [Ref 6]

How Does An Earthquake Contribute To Other Natural Disasters?

Earthquakes are classified in categories ranging from minor to great, depending on their magnitude. [Ref 8] [See ​Table 1​] E ​ arthquake magnitude is measured on the Richter Scale. ​The Richter scale is a scale developed in 1935 by Charles F. Richter to compare the size of earthquakes. On the Richter scale, magnitude is shown in whole numbers and fractions. As an example, an earthquake with a 5.1 magnitude​ would be a moderate earthquake but an earthquake with a ​6.3 magnitude​ would be considered a strong earthquake.[See ​Table 1​] An estimate of the energy created by an earthquake is incremented such that each whole number step on the magnitude scale is the equivalent of about 31 times more energy than the previous number.​ [Ref 34]​ The top 5 largest earthquakes ever recorded are identified below. [See ​Table 2​] A tsunami that may follow an earthquake under the sea may bring massive destruction and flooding to low lying coastal zones. ​In December 2004, the day after Christmas, an earthquake with a ​9.1 magnitude​ erupted in the Indian Ocean propelling massive columns of water toward the shores of Thailand. About 5,400 people were killed as a result of this tsunami. The earthquake lasted for 10 minutes releasing as much pent up power as several thousand atomic bombs.​ [Ref 35] Earthquakes may also cause roads to collapse, landslides, mudslides or even rupture of structures such as bridges and overpasses. [Ref 9]

Magnitude

Table 1: Earthquake Magnitude Scale

Category

Earthquake Effects

Estimated Number Each Year

2.5 or less

Minor

Usually not felt, but can be recorded by seismograph.

900,000

2.5 to 5.4

Light

Often felt, but only causes minor damage.

30,000

5.5 to 6.0

Moderate

Slight damage to buildings and other structures.

500

6.1 to 6.9

Strong

May cause a lot of damage in very populated areas.

100

7.0 to 7.9

Major

Major earthquake. Serious damage.

8.0 or greater

Great

Great earthquake. Can totally destroy communities near the epicenter.

20 One every 5 to 10 years

Table 2: Top 5 Largest Recorded Earthquakes [Ref 10]​[Ref 11] Name of Earthquake

Magnitude

Location

Date

Valdivia Earthquake

9.5

Chile

May 22, 1960

Prince William Sound Earthquake

9.2

Alaska

March 27, 1964

Sumatra-Andaman Islands Earthquake

9.1

Northern Sumatra

December 26, 2004

Tohoku Earthquake

9.1

Honshu Japan

​March 11, 201​1

Kamchatka Earthquake

9.0

Kamchatka Peninsula, Russia

​November 4, 1952

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

What Should You Do To Prepare For And Recover From An Earthquake?

Whether someone resides in an earthquake zone, or they’re on vacation, earthquakes can hit at any moment. Families should be equipped with the right essentials and knowledgeable of the steps to obtain little to no injuries or damage. Communication is vital when it comes to the impact and recovery of such events. Landline phones (as opposed to mobile phones) and portable radios can mean the difference between life and death during and after an earthquake as these devices will allow you to receive updates on information and safety advisories in and around your community. [Ref 22] There are many steps you should take that should be taken to prepare yourself for a disaster like an earthquake or other disaster. Listed below are four recommended simple steps to prepare for a disaster like and earthquake: ❏ ❏ ❏ ❏

Step 1. Secure your space Step 2. Make a Plan to be safe Step 3. Organize disaster supplies Step 4. Minimize financial hardship

To avoid having to pay extra in the event of an earthquake, you can pay for earthquake insurance in advance. This is most useful if you live in an earthquake zone because this assistance can allow someone to get back on their feet after an earthquake easier than someone who did not have earthquake insurance. This insurance covers damages caused by an earthquake which is generally not included in standard homeowners or renters insurance policies. This insurance covers damage that may occur to someone’s dwelling and/or garage that is attached to that dwelling. Earthquake insurance also covers the cost associated with removing debris in the surrounding area of your dwelling. [Ref 32] [Ref 33]

What Are Structural Engineers and What Do They Do? Structural engineers design and construct buildings and structures that are safe and can withstand the elements. Structural engineers also work on preventing serious damage done to buildings after a natural disaster. ​[Ref 42] ​Structural engineers work with architects to design and develop a blueprint and/or construction plan for buildings and other structures. An important job of a structural engineer is to be knowledgeable of the applicable state’s building codes and how the environment could affect the building. Each state typically has a website where building codes can be researched.

How Do Structural Engineers Minimize The Damage Done From An Earthquake?

Some buildings are constructed very well to survive an earthquake. An efficient way of making earthquake resistant structures is by creating a “flexible foundation” where the building is built on top of flexible pads. When an earthquake strikes, only the base of the building moves while the rest of the structure remains steady. Another technique used to reinforce the building's structure is through the use of shear walls and moment resisting frames. Moment resisting frames keep joints firm while allowing the structure to bend. Shear walls transfer movement away from the structural members to the building foundation. ​[Ref 44] ​Structural engineers also use various technology and mechanisms to try and minimize damage done from earthquakes. They use base isolators and vibration control devices to reduce the force of an earthquake. Another thing they use is “seismic isolation. This reduces shaking by placing rubber, oil, or other substances between a structure and the ground which creates a cushion to absorb the energy from earthquakes. ​[Ref 40&42]​ In Japan, engineers have developed a few advanced ways to minimize the damage caused by an earthquake. One of those ways is called the Water Discharge Tunnel. This is a hidden tunnel that collects flood water caused by natural disasters and safely redirects that water to the local Edo River. So in the event of an earthquake that causes a tsunami, the rapid inflow of water from the ocean would be funneled down the tunnel thereby sparing the city of any major flooding.

[Ref 39]

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

MATERIALS & METHODS Purpose The purpose of the scientific experiment is to create models of building styles that will be subjected to vibration in the simulator and to observe the response of each model to varying inputs of vibration magnitude and vibration time.

Methodology (Materials and Methods) The experiment setup consisted of the following items: ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖

Miniature Marshmallows Toothpicks (Box of at least 30) Cardboard Shoe Box Rubber Bands (Bag of at least 30) Marbles (Bag of 30 – 50) Vibration Shaker Unit Stopwatch Camera (Optional) Pen/Pencil Test Notebook

The Cardboard “simulator” was constructed using the materials identified above. The experiment was then conducted by NSBE Jr. Member Jonathan Winstead II and advised by NSBE Jr Advisor, Jon Winstead. Additional NSBE Jr Advisor assisting with the experiment were Dr. Toni Arnold-McFarland and Mr. Trey Arnold.

Jonathan Winstead II began the exploratory process by drafting several building concepts in a notebook which were reviewed by Jon Winstead. After reviewing feedback provided by Jon Winstead, Jonathan Winstead II down-selected the multiple design concepts to just four (4) models that would be further analyzed. The four design concepts are identified below as Concept A, Concept B, Concept C, and Concept D.

Table 3: Building Concepts To Be Tested

Concept ID A

Description

Dimensions

Toothpick Qty

Marshmallow Qty

36

94

Rectangular Building Shape

5” Base x 2” Width x 3” Height

B

Triangular Building Shape

3” Base x 3” Height

13

10

C

Square Building Shape

4” Length x 4” Width X 4” Height

25

23

D

Rhombus Building Shape

6” Length 3” Width 2” Height

18

30

Concept A was constructed and then placed on a flat table. Pictures of the concept were taken. Concept A was then placed on the shaker platform inside of the cardboard box. The cardboard box was then placed on the vibration shaker unit. Concept A was then subjected to low frequency (15 Hz) vibration for a period of three (3) minutes as timed by the stopwatch. Concept A was observed for structural integrity and if/when the building concept collapsed. A time of collapse (as applicable) was noted in the test notebook along with any other observations witnessed by the observers. If no collapse was observed, the building concept was then subjected to high frequency (60 Hz) vibration for a period of one (1) minute. Any observations were noted in the test notebook. Post test pictures were taken of the concept after vibration testing. We used a 4" Round Lab Vibrator - Dental Laboratory Equipment Vibrator Oscillator Shaker to perform the testing. It operates from 0 - 60 hertz. The above process was repeated for Concept B through Concept D and the data was recorded in the test notebook.

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES

RESULTS The results of the simulated vibration tests are noted in ​Table 4​ below. In this round, we controlled the frequency and time only at specific levels.

Table 4: Results and Observations from Vibration Simulations Concept ID#

Shape

Vibration Frequency

Vibration Time (Minute)

Collapse (Y/N?)

Observations

Trial

A

Rectangle

Low

1

3

N

Less Sturdy. Stayed together but moved a lot

A

Rectangle

High

2

1

N

Less Sturdy. Moved a lot, more movement than trial 1

B

Triangle

Low

3

3

N

Sturdy, moved less than concept A

B

Triangle

High

4

1

N

Sturdy, moved more than trial 3

C

Square

Low

5

3

N

C

Square

High

6

1

N

Not sturdy, moved a lot

D

Rhombus

Low

7

3

N

Not study, moved a lot

D

Rhombus

High

8

1

N

Not study, moved a lot, some structural failure

Not study, moved a lot

DISCUSSION Round 1 Date:​ Jan. 23 2021 Team Member(s) present:​ Jonathan, Nana, Imani, Daniel, and advisor Jon Winstead.

Concept A​ through ​Concept D​ were tested on the vibration shaker with the observed results as shown in Table 4​. Based on the results of the testing, It was surmised that the triangle structure would more likely survive vibration at a higher frequency than the square, rectangle and rhombus structures. The team reviewed the test data and concurred that the strength of the structures could be ranked from strongest to weakest in the following order: (Strongest)​ -----------------------------------------------> ​(Weakest) Concept B Concept C Concept A Concept D After completing these trials, we realized that we wanted to have a second round of trials to see what frequency and vibrating time would cause the structures to collapse. Based on observations from round 1, it was agreed that only the triangle and rhombus, which represented the strongest and weakest structures, respectively, would be tested during round 2.

Round 2 Date:​ Jan. 30 2021 Team Member(s) present:​ Jonathan, and advisor Jon Winstead.

Concept B and Concept D were tested on the vibration shaker with the observed result as described below. For this round the structures were installed on the vibration shaker and secured to the vibration platform to prevent the overall movement of the structure that was observed during round 1 trials. Both structures were tested with the vibration set to high frequency. Concept B was tested and began to come apart in approximately ​15 minutes and 23 seconds​. It was noted that the rest of the structure seemed to be still intact which the team member hypothesized that this was probably due to uneven construction of the structure during the original build.Concept D was tested under the exact same conditions as Concept

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Running Head:THE IMPACT OF AND RECOVERY FROM EARTHQUAKES B however this structure began to come apart in approximately ​7 minutes and 58 seconds​.​ ​Round 2 testing of the two (2) selected structures provided the team members with some valuable insight on the response of different structures to vibration. As expected, Concept B (Triangle) survived longer under the same vibration conditions as compared to Concept D (Rhombus).

CONCLUSION The findings from our research and experiments suggest that the best “earthquake resistant” structure was the triangle due to the fact that it had the most supportive base compared to the other models that we tested. We believe that the triangle structure was a more structurally sound geometric shape when considering the impact of earthquakes. Additionally, our research led us to ask the question, “What types of structural designs are most protective against earthquakes in various regions of the world? We found that in Japan, where earthquakes are the highest on the Richter scale, ​Dome shaped buildings are the most prevalent designs used when building earthquake resistant buildings,​ In California, the best structural designs used are dome steel framings. Throughout California several different methods are used to build earthquake resistant structures ranging from wood-frames and flimsy floors to steel framed buildings. The California building designs would most likely survive earthquakes with a magnitude of between 2.5 and 6.0 on the Richter Scale. ​[Ref 46].​ In South America, the most prominent type of building structure used are also dome shaped structures which are rated to be most protective for large magnitude earthquakes measuring between 5.0 and 7.0 on the Richter Scale. Performing this research has provided some valuable knowledge to the team members and we are sure that this information will be useful for us as we matriculate to high school and then onto whatever college or university we eventually attend.

REFERENCES The Key references are listed below. Click ​Full Reference List​ for all used in this research. [​Ref 1]​ ​United States Geological Society​ [ USGS],​ ​ Accessed 12 Dec. 2020.

[Ref 2]​ ​American Museum of Natural History [Amnh]. Plate Tectonics Part Of Hall Of Planet Earth​, Accessed 18 Jan. 2021 [Ref 4]​ ​United States Geological Society [ USGS].Ring Of Fire,​ ​Accessed 12 Dec. 2020 [Ref 6]​ Ring of Fire January 2021​, Accessed 1 Jan. 2021 [Ref 8] H ​ ow Are Earthquake Magnitudes Measured? 2007​, 18 Jan.21 [Ref 10] ​Most Powerful Recorded Earthquakes​, ​Accessed​ 1 ​ 8 Jan. 21 [Ref 11]​ U ​ nited States Geological Society [ USGS]. A list of the 20 largest earthquakes in the world​, Accessed​ ​Jan. 5 2021 [Ref 35] ​Deadliest Tsunami​, Accessed December 19th 2020 [Ref 42] ​Complete Building Solutions​, Accessed December 19th, 2020 [Ref 46] ​Japanese Skyscrapers​, Accessed February 1, 2021

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