The Earthquake dilemma

During an earthquake everything shakes and objects will fall. To protect yourself you need to hide under something. The international standard states that you should hide under a table or something solid to protect yourself from falling objects; “Drop, Cover and Hold on”. Another standard that is gaining growing popularity and criticism is “The Triangle of Life”. This is to lay next to something solid (a fridge, a bed or a car); if something heavy fall straight down you will be better protected.

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Here starts the argument. If the roof falls down, a small table will not stop it from falling. At the same time, when an earthquake shakes the house small items will fall and fly uncontrolled around. If you lay beside a solid object you might become hit by something. In both methods you will be exposed for a potential danger, and they are relatively contradictory to each other. Both got valid argumentation and might be the best option.

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Most earthquakes is weak (<4R), few are medium (4R-6R), very seldom strong (>7R), and almost never extremely strong (<9R). Weak earthquakes is not dangerous and don’t create damages. When it starts to shake we might be scared, but nothing really happens. The medium earthquakes are more interesting here the lamps swing heavily and smaller items might fall, meaning we need to take care. The strong earthquakes can make a house to collapse; the stronger it gets the higher chance for a collapse. It is perhaps here we might find the application for the two different techniques. In weak earthquakes you don’t need to do anything, but you don’t know the real strength before after the earthquake. This only indicates you need to act as it is a strong earthquake to protect yourself, because it might be strong. Never say this is only a weak earthquake – It might be a strong one.

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Almost all the earthquakes do never pass the 7R limit; they seldom become strong. In other words, an earthquake is almost never stronger than medium. We need to prepare for the worse (a strong) and hope for a weak. Statistically we should expect a weak and prepare for a medium. Let us say you do the perfect protection drill for a medium earthquake (drop, cover and hold on), crawl under a table to protect against the falling smaller objects. This drill is totally a waste of time in a small earthquakes; nothing will fall! If you do the same in a strong earthquake you might be up for a surprise – The table will not protect you from the falling roof. Then let us go back to the statistics. The chance of survival when a house collapses is from zero to low; no matter what you do! Also remember that the chance for a total collapse of a building is also extremely low; close to zero. Let us say that you prepare for a strong earthquake and lay down next to a solid object; “The triangle of life”-drill. Smaller items like lamps, books, plates, remote controls and decorations will fly through the air and most likely they will hit, cut and damage you. In medium earthquakes we might find this solution potential dangerous and even stupid. In hard earthquakes you are better off hiding next to something solid (“the triangle of life”) and relatively close to the external wall (not next to it!). In medium earthquakes you are better off hiding under a table (“Drop, Hide and hold on”) and far away from the external wall. Strong earthquakes are rare, sudden and with little time to act. Often you cannot do anything to protect yourself and most likely you will die if the building falls down. Medium earthquakes are more common and you might protect yourself from unnecessarily damages by hiding under your desk. The official advice from WFET is “The Drop, hide and hold on” drill.

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When a strong earthquake (>8R) hit and a building collapses we will only have a few seconds to get out.  First we need to get aware of the earthquake (feel the first shakes), notify the others, run down the stairs to get out is pure fantasy in cases without alarm. You simply don’t have sufficient time! If you have time to hide under a table you will crushed. If you lie next to the fridge, it might fall on you. Remember the building will fall down and you will most likely die in the rubble. Let us say you start running out like crazy when you feel something. The chance for you to survive is still limited. You got just a few seconds, the floor moved up and down, and here and there, you will have problems with your balance and fall. Things fall from everywhere and hit you, glass flies from the broken windows and cuts you, parts of the houses outer walls start to fall make it difficult to move, the stairs shakes different from the floor due to a shift in frequency. There you are running for your life. If the house collapses, then you are in huge trouble. The best chance of survival is running up instead of down and out. You need to lie down next to something solid not too far from the external wall. Then you simply need to hope for the best. Note that running in the stairs is a bad idea DURING an earthquake. Before it is okay and after only with care. Stairs have a different frequency than other structures (walls, roof and floor) the rest of a building. Earthquake creates damages in the structure; try to avoid areas with damages. The chance for success is low. Theoretically in a situation like above, you will have a bigger chance for survival being next to an object; that doesn’t fall on you. Now, remember this <8R earthquakes is very rare, and many houses can resist up to the extremely rare <9R. In other words, this is not a common scenario.

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It exist many advices and things to do before, during and after an earthquake. We can give a lot of earthquake advices, but we need something functional – a tactical emergency plan. If you are inside a collapsed building you are more likely to survive if you are close to the outside of the building – don’t stay deep inside a building. Always remember the rescue workers will first come to the external and work themselves inwards. The longer in you are the more equipment/ technology is needed to get you out, and the more time will pass. In other words the risk of death increases the more inside the building you are. At the same time you need to remember, the first that collapses in a building is the external wall! The closer you are to the external wall, the bigger chance for you to die. If you are close to the exterior wall you might die quickly. In other words the risk of death increases the closer to the external wall you are. The advice from WFET is to stay away from the external wall, but don’t go to deep inside the building.

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Another aspect is high up – or down in the building. The closer to the ground floor you are when the building collapses straight down (most frequent) the more weight is on top of you. The more weight – the bigger chance to die. If you get higher up in the building before it collapses you will have less weight on top of you – an increased chance of survival. If the building falls to the side instead of collapsing straight down you will be safer on the ground floor. The advice from WFET is in weak buildings that will collapse is to stay high. You will fall, you will be injured, you will be buried in rubble, but you got a better chance to survive.

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Everything really depends on strength of the earthquake, the structure of the house and where you are in the house when the earthquake strikes. It is no magic formula to earthquake survival, but advises based on common sense and probabilities. The best advises might lead directly to death and the worst advise might lead to survival. Follow the emergency program where you are. If it doesn’t exist one, make one.

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This is just a recommendation developed by WFET. The recommendation builds on the CLAE evaluation; Construction, Localization in construction, Area and strength of the Earthquake. CLAE is basically a preventative strategy where you intent to place yourself on the less dangerous spot.

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Good luck and stay safe!