|This question takes on a greater significance because there are several coastal communities along our Nation’s West Coast that are vulnerable to tsunami triggered by an earthquake on the Cascadia Subduction Zone. An earthquake along this fault could potentially generate a tsunami within minutes, similar to what happened on the north end of Sumatra. Given that many of these coastal communities are located in areas that would be impossible to evacuate in time, and could result in a significant loss of life, FEMA and its mitigation partners at the Federal, State and local levels are looking for alternatives. The only feasible alternative would be vertical evacuation, providing such a structure could be constructed to resist tsunami loads.|
For the average structure, it would generally not be economically feasible to construct to withstand the extreme loads of a tsunami. However, we believe it would be possible that a specially designed structure could be built to withstand at least specific tsunami loads without collapse for the purposes of providing community shelter for vertical evacuation. Similarly, the same criteria could possibly be used if the structure was to house a large occupancy load (such as some larger seaside resorts).