Haiyan's Storm Surge: A Detailed Look

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Haiyan's Storm Surge: A Detailed Look

 

 

The Philippines is a nation used to seeing devastating typhoons. Between 1984 and 2012, the Philippines saw seven tropical cyclones that killed at least 1,000 people. In all of these storms, it was destructive flooding due to heavy inland rains that was the main killer. This is in contrast to the Atlantic basin, where storm surge from the ocean has historically been the main killer. That's due, in part, to the fact that the Philippines gets hit more often by intense tropical cyclones than any place in the world, and this has influenced settlement patterns. The portion of the coast most prone to typhoon strikes--the east coast of Luzon Island--is not heavily populated, and does not have any major cities at low elevation that are prone to large storm surges. The islands of the Philippines farther to the south, like Leyte, Samar, and Mindanao, are hit far less often, since they are closer to the Equator, where typhoons have a tougher time getting spinning due to the lack of an extra boost from Earth's rotation. This relative lack of typhoon strikes has allowed more settlement on the east coast, and Tacloban (population 221,000) is the largest city on the Philippines' east coast. Tacloban also happens to be low-lying, with much of the city at less than ten feet elevation. It's position at the pointy end of a funnel-shaped bay makes its location particularly vulnerable to storm surge, since the topography acts to concentrate water at the apex of the funnel. The occurrence of a massive storm surge disaster in Tacloban was only a matter of time, and that time happened to be November 8, 2013, during Super Typhoon Haiyan.