Many people are wondering what a storm surge is. Why did it happen in Tacloban? Why was it not predicted by PAGASA as one of the effects of Typhoon Yolanda? Where in the country can storm surges occur?
I was wondering, too, although I have used the term as one of the effects of severe weather conditions in talks on the effects of climate change.
During a typhoon, atmospheric pressure in the affected area is low. If one looks at the published predicted tidal level during a typhoon, he would find that the prediction is lower than the actual tidal level. The reason is because seawater from somewhere has moved to the typhoon-affected site.
In fact, the predicted level in the tide tables would appear incorrect during typhoon times. Marine biologists doing tidal measurements in the course of research are warned of taking account of this anomaly.
But as explained later in this essay, storm surges like that which occurred in Tacloban was caused by a huge volume of seawater pushed by a very powerful storm, Yolanda, into the funnel-shaped structure with an eastward opening towards the Pacific Ocean and the very narrow channel between Leyte Island and Eastern Samar.
This enormous volume of water could only move slowly and therefore, caused the destructive flood or storm surge in Tacloban on Nov. 8th.
On searching for the published materials on the subject of storm surge, I came across the Reader’s Digest book titled Extreme Weather, where there is a brief explanation of storm surges. This account mentions that on Feb.1, 1953, “a storm tore down through the North Sea on a high spring tide, ramming an enormous volume of water into the funnel-shaped English Channel. The water was squeezed between the Continent on one side and Britain on the other, and the water level rose rapidly higher. Whipped up by the winds of the storm, huge waves smashed through the flood defences of eastern England and the mouth of the Thames estuary, very nearly swamping London. The speed of the surge caught people completely unawares and 300 drowned.”
One question is, where else in the country did a powerful storm surge occur in the past? The answer is, in Ormoc, where a similar funnel-shaped structure exists.
Where else in the Philippines are potential storm surge areas? One can look at the map of the Philippines and identify these areas.
Many thoughtful people are asking PAGASA and our weather authorities to please mount an educational campaign to tell our people more about storm surges so that proper preparations can be made by the people before a storm strikes.
Already, PAGASA has shown us that it can accurately predict the exact sites hit by a typhoon. It should do likewise for sites of potential storm surges.
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Author’s email: suakcrem@yahoo.com
