Thursday, December 3, 2009

Surveying Tsunami Damage in American Samoa

On September 29th, 2009, an 8.3 magnitude earthquake generated a tsunami that devastated the island of American Samoa. Three waves, the highest reaching almost 36 feet, crushed coastal structures, shorelines and coral reefs, killed 150 people and left a laboratory for researchers who study the mechanics of what is one of the most destructive forces in nature.

Using a Remotely Operated Vehicle (ROV), Professor Julie Young and a team of researchers in the University of Michigan's Department of Naval Architecture and Marine Engineering surveyed the coastal seabed.

A tsunami, a series of huge waves that travel in all directions from the area of disturbance, can reach heights of 100 feet and travel in the open sea as fast as 450 miles per hour. It ravages not only the visible coastal area but nearby seabed. This video shows some of the underwater wreckage that the American Samoa tsunami left behind -- in the first half you'll see marine debris washed out on to the coral reef offshore of Poloa, a village wiped off the southwest corner of Tutuila, American Samoa, during the tsunami. The debris includes metal sheet roofing, tires, clothing, plastics and other more unusual odds and ends. The second half of this video shows the tsunami-inflicted damage to the coral reef off the coast of Leone, which is also on the southwestern coast of Tutuila.