Tuesday, July 23, 2019

The 1958 Lituya Bay Megatsunami Term Paper Example | Topics and Well Written Essays - 2500 words

The 1958 Lituya Bay Megatsunami - Term Paper Example since about 1940, but in the years after that, the fiord – like bay had increasingly been used by fishermen ‘as an overnight anchorage for their trolling boats and as a refuge in bad weather’ (Miller, 1960). As the second half of 1958 dawned, a catastrophic event on an unprecedented scale occurred in what used to be a safe anchorage, causing a massive trail of destruction and taking two human lives. The eyewitnesses’ accounts, the subsequent observations and measurements docum-ented by Miller in great detail in his comprehensive report published by the U.S. Geological Survey, as well as the extensive survey conducted by Captain Elliot B. Roberts, all together, shed light on what had happened that day. On July 9, Pacific Standard Time, a major earthquake, with a magnitude of 7.9 on the Richter scale, although being reported by some sources as much as 8.3, occurred along the Fairweather Fault. The epicenter had been reported at latitude 58.6`N and longitude 137.1`W, at a point about 7.5 miles east of the surface trace of the Fairweather Fault and 13 miles southeast of the head of Lituya Bay (Brazee & Cloud, 1960). Based on the eyewitness accounts and on the field observations of his own on July 10, 1958, Miller stated that within 1 to 3 minutes after the earthquake, a giant wave front moved out from the head of the bay and ‘swept 7 miles along the shores to the mouth of Lituya Bay in about 4 minutes, destroying the forest over an area of 4 square miles and sinking two boats’ (Miller, 1960). Further in the same paper, Miller specified that due to the wave, the trees had been washed out to a maximum height of 1Â  720 feet, which is considered about eight times the maxim um altitude of damage ever attributed to a tsunami or to a localized wave of any kind (Miller, 1960). The proposed mechanisms responsible for the giant, 1Â  720 feet wave have been an object of subsequent research and analyses, like those of Pararas-Carayannis (1999), Mader (1999), Mader

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