Duck, Cover, and Hold On!Aug 18 2015 · 0 comments · NISHKIAN MENNINGER, Seismic ·0
As structural engineers, and with the recent large earthquakes around the world, the latest earthquake disaster movie moving out of theaters–and yesterday’s 4.0 magnitude earthquake that jolted East Bay residents awake, we get a lot of questions about what to do during an earthquake. We have gotten this question from family members and friends, and even a stranger at a bar who overheard our conversations. Surprisingly, I have been able to use a scene in the movie San Andreas to better illustrate the answer this question: duck, cover, and hold.
It has been shown that the number one cause of harm during an earthquake in the U.S. is falling objects. These are items like lights, signs, ceiling tiles, and broken glass. To avoid getting hurt by these objects, it is the consensus of the engineering society to duck, cover, and hold. Specifically, get under a surface, cover your head, and hold on to the legs of the surface. This way you will be well hidden from falling objects, and the surface won’t roll or slide away from you in the event of large shaking.
If you are outside, don’t run inside. Building exteriors such as glass or brick and building appendages such as signs or lights may dislodge from their supports and pose a significant risk to you. You will want to look up and assess your position. If you are next to an old brick building, for instance, you should safely move away from the building. Likewise, if you are inside a building, don’t run outside. Buildings are safer to be inside than directly outside. Find a safe place to duck and cover during the earthquake, and wait until the shaking fully stops before exiting the building.
Two other frequently asked questions are: what to do when in bed, and if a door frame is a safe place to be. First, if in bed during an earthquake, you should stay there. The recommended action is to cover your head with a pillow and remain in place. However, if you have a large item above you that poses a risk of falling, you may want to leave the bed and find a place to duck and cover. The door frame was considered a safe place to be during an earthquake. However, this does not protect you from falling hazards.
The “Triangle of Life” method is not backed by the Structural Engineers Association of California (SEAOC). The Triangle of Life method tells people not to duck, cover, and hold– but to find an object and squat next to it. The theory here is that in the event of a building collapse, rubble would fall partially on this object and partially on the floor, creating a void space for you to survive in. However, this method is only applicable to regions where construction and seismic design techniques are not as advanced as in the U.S. Buildings are designed to remain standing, greatly reducing the applicability of the triangle of life technique.
For more information about protecting yourself during an earthquake, and about the flaws of the triangle of life, please see the links below: