Thursday, July 17, 2008

World's Biggest Tsunami | 1720 feet-tall - Lituya Bay, Alaska

World's Biggest Tsunami | 1720 feet-tall - Lituya Bay, Alaska:
"On the night of July 9, 1958 an earthquake along the Fairweather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet (see map below). The impact generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet. The wave hit with such power that it swept completely over the spur of land that separates Gilbert Inlet from the main body of Lituya Bay. The wave then contiuned down the entire length of Lituya Bay, over La Chaussee Spit and into the Gulf of Alaska. The force of the wave removed all trees and vegetation from elevations as high as 1720 feet (524 meters) above sea level. Millions of trees were uprooted and swept away by the wave. This is the highest wave that has ever been known. ..."
This is a fascinating story with contemporary eyewitness accounts, photographs, maps, and aerial photography.

A geologist was in the process of studying Gilbert Inlet for evidence of large waves in the past. There were at least four such waves in the past 150 years. This one not only dwarfed them all, but it erased all evidence that the earlier waves had even occurred.

It just boggles the mind to think how much energy was expended so as to mow down spruce forests at a height of 1720 feet above sea level -- and all this in an area roughly 2 miles wide and 7 miles long.

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