Monday, November 25, 2013

Surprise By Typhoon Haiyan (international name) Storm Surges hits VisayasRegion

Hours before Typhoon Haiyan hit, Philippine authorities moved 800,000 people to sturdy evacuation centers — churches, schools and public buildings. But the brick-and-mortar structures were simply no match for the jet-force winds and massive walls of waves that swept ashore Friday, devastating cities, towns and villages and killing thou
sands, including many of those who had huddled in government shelters.
The tragedy is another reminder that nature's fury is sometimes so immense that it can overwhelm even the most diligent preparations. Combine that with a string of unfortunate circumstances — some man-made — and the result is the disaster of epic proportions that the country now faces.
Some officials estimate that 10,000 or more people were killed by Haiyan, washed away by the churning waters that poured in from the Pacific or buried under mountains of trash and rubble. But it may be days or even weeks before the full extent of the destruction is known.

What is STORM SURGE?


storm surge is an offshore rise of water associated with a low pressure weather system, typically tropical cyclones and strong extratropical cyclones. Storm surges are caused primarily by high winds pushing on the ocean's surface. The wind causes the water to pile up higher than the ordinary sea level. Low pressure at the center of a weather system also has a small secondary effect, as can the bathymetry of the body of water. It is this combined effect of low pressure and persistent wind over a shallow water body which is the most common cause of storm surge flooding problems. The term "storm surge" in casual (non-scientific) use is storm tide; that is, it refers to the rise of water associated with the storm, plus tide, wave run-up, and freshwater flooding. "Tidal surge" is incorrect since there is no such thing. When referring to storm surge height, it is important to clarify the usage, as well as the reference point.