05 November 2013

Earthquake Survival: "Triangle of Life" vs. "Drop, Cover, and Hold On"

magnitude 7.2 earthquake hit the Visayas

On October 15, 2013, a magnitude 7.2 earthquake hit the Visayas, leaving more than 200 people dead, 800 people injured, 69,000 structures damaged, and over 3 million individuals affected. Prominent sites i.e. centuries-old churches and the Chocolate Hills got their share of the devastation, leaving locals in shock and despair. Considering the Philippines’ location in the Pacific Ring of Fire, events like this are no stranger to our history books. Therefore, we must know what to do before the next “big one” arrives.

With regards to earthquake survival, “Drop, Cover, and Hold on” has been the staple method. In the past years, emails have been circulating discouraging people from practicing the said method and promoting the “Triangle of Life”, leaving people in confusion. In this article, we will try to dissect the two and make recommendations.


Earthquake Safety tips



Drop, Cover, and Hold On



It is the national standard for earthquake safety in the US.
drop, cover, hold on


More specifically:
1. Drop under something sturdy and taller than you are.
2. Cover the back of your head and neck with one arm.
3. Hold on in case the thing you’re under moves.
4. Close your eyes. You’ll do better psychologically if you don’t watch, and you’ll protect your eyes.



Triangle of Life


Doug Copp, the Triangle of Life’s proponent, has circulated emails on how his new technique could save lives based on his experience in rescue missions in Turkey and in various places.

Triangle of Life



The following are excerpts from his email:


1. Most everyone who simply 'ducks and covers' when building collapse are crushed to death. People who get under objects, like desks or cars, are crushed.


2. Cats, dogs and babies often naturally curl up in the fetal position. You should too in an earthquake. It is a natural safety/survival instinct. You can survive in a smaller void. Get next to an object, next to a sofa, next to a bed, next to a large bulky object that will compress slightly but leave a void next to it.


3. Wooden buildings are the safest type of construction to be in during an earthquake. Wood is flexible and moves with the force of the earthquake. If the wooden building does collapse, large survival voids are created. Also, the wooden building has less concentrated, crushing weight. Brick buildings will break into individual bricks. Bricks will cause many injuries but less squashed bodies than concrete slabs.


4. If you are in bed during the night and an earthquake occurs, simply roll off the bed. A safe void will exist around the bed. Hotels can achieve a much greater survival rate in earthquakes, simply by posting a sign on the back of the door of every room telling occupants to lie down on the floor, next to the bottom of the bed during an earthquake.


5. If an earthquake happens and you cannot easily escape by getting out the door or window, then lie down and curl up in the fetal position next to a sofa, or large chair.


6. Most everyone who gets under a doorway when buildings collapse is killed. How? If you stand under a doorway and the doorjamb falls forward or backward you will be crushed by the ceiling above. If the door jamb falls sideways you will be cut in half by the doorway. In either case, you will be killed!


7. Never go to the stairs. The stairs have a different 'moment of frequency' (they swing separately from the main part of the building). The stairs and remainder of the building continuously bump into each other until structural failure of the stairs takes place. The people who get on stairs before they fail are chopped up by the stair treads - horribly mutilated. Even if the building doesn't collapse, stay away from the stairs. The stairs are a likely part of the building to be damaged. Even if the stairs are not collapsed by the earthquake, they may collapse later when overloaded by fleeing people. They should always be checked for safety, even when the rest of the building is not damaged.


8. Get near the outer walls of buildings or outside of them if possible - It is much better to be near the outside of the building rather than the interior. The farther inside you are from the outside perimeter of the building the greater the probability that your escape route will be blocked.


9. People inside of their vehicles are crushed when the road above falls in an earthquake and crushes their vehicles; which is exactly what happened with the slabs between the decks of the Nimitz Freeway. The victims of the San Francisco earthquake all stayed inside of their vehicles. They were all killed. They could have easily survived by getting out and sitting or lying next to their vehicles. Everyone killed would have survived if they had been able to get out of their cars and sit or lie next to them. All the crushed cars had voids 3 feet high next to them, except for the cars that had columns fall directly across them.


10. I discovered, while crawling inside of collapsed newspaper offices and other offices with a lot of paper, that paper does not compact. Large voids are found surrounding stacks of paper.



Analysis


We can classify indoor structural earthquake hazards into three: falling fragments, collapsing ceilings, and toppling walls. For each hazard, we evaluate the danger it poses a person depending on the technique he/she uses: 1 – absolutely safe, 2 - safe, 3 - slightly dangerous, 4 - dangerous, 5 - very dangerous.

Falling Fragments
Collapsing Ceiling
Toppling Wall

A scientific journal on the various injuries caused by a catastrophic earthquake in Wenchuan, China on May 12, 2008 was published in 2010.





It can be observed that most injuries were caused by “blunt strikes” or body impacts due to falling things during the shaking of the ground with 2213 people affected. “Crushing/burying” came next with 608 cases. Other studies support that most injuries caused by earthquakes are due to falling debris. In addition, countries with good building codes have fewer tendencies to experience collapsing of entire structures.



Conclusion



The Philippine Building Code incorporates seismic loads up to magnitude 8.0. The Bohol incident, according to experts, was a testament to the poor implementation of the code. Therefore, in order to survive an earthquake, one must ensure that the Building Code is properly implemented and follow the Drop, Cover, and Hold On technique.




References:
http://www.ndrrmc.gov.ph/attachments/article/1108/UPD%20re%20SitRep%2030%20re%20Effects%20of%207.2%20EQ,%20Bohol%20%2829OCT2013%29.pdf
http://www.earthquakecountry.info/dropcoverholdon/piy_drop_cover_hold.pdf
http://www.rappler.com/thought-leaders/41766-lessons-bohol-disaster-part-1
Journal: Analysis of injuries and treatment of 3 401 inpatients in 2008 Wenchuan earthquake—based on Chinese Trauma Databank
https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-frc3/1395252_622511177791024_1630347253_n.jpg
http://cdn.theatlantic.com/static/infocus/philquake101613/s_p23_RTX14DES.jpg
http://reidh4.edublogs.org/files/2011/01/drop-cover-hold-on-20mmalu.jpg
http://www.rappler.com/life-and-style/technology/41743-triangle-life-hoax
http://kitchen-pictures.bloginterior.com/files/2011/02/115854-magic-marker-icon-people-things-table-sc52.png
http://www.clker.com/cliparts/4/4/7/4/1197098505103048288addon_the_couch.svg.med.png
http://gwadzilla.blogspot.com/uploaded_images/brick3-726715.JPG
http://www.iris.edu/hq/gallery/photo/4439

3 comments:

  1. what about in condos? would it be advisable to hide in an elevator shaft?

    ReplyDelete
  2. The universally accepted recommendation is not to hide inside an elevator/elevator shaft. There is a possibility that you would get trapped inside, although there is little probability that you could get injured.

    ReplyDelete