Difference between tsunami and other water waves
May 24, 2010 I Coastal area issues, Great Tsunami, tsunami report.Tsunamis are different from wind-generated waves, which many of us may have observed on a local lake or at a coastal beach, in that they are characterized as shallow-water waves, with long periods and wave lengths.The wind-generated swell one sees at a California beach, for example, seeded by a storm out in the Pacific and rhythmically rolling in, one wave after another, might have a period of about 10 seconds and a wave length of 150 m.
A tsunami, on the other hand, can comprise a wavelength in excess of 100 km and period on the order of one hour.
As a result of their long wave lengths, tsunamis usually behave as shallow-water waves.A wave becomes a shallow-water wave when the ratio between the water depth and its wave length gets very less.Shallow-water waves travel at a speed that is equal to the square root of the product of the acceleration of gravity (9.8 m/s/s) and the water depth.
» Earthquake at Samoa, Current earthquake, Tsunami disaster, Earthquake information, Tsunami alert, Earthquake safety, Tsunami warning center, Earthquake prediction, Tsunami relief Says:
[…] A magnitude 8 earthquake close to Samoa on Sept. 29 destroyed 34 people in American Samoa, 183 in Samoa and nine in Tonga, when tsunami waves up to 46 feet (14 meters) high crashed ashore. […]
May 24, 2010, 6:35 am