www.geophys.washington.edu/tsunami/movies/globe.mov
library.thinkquest.org/C0115522/images/illustrations/34.2.jpg
Tsunami Research
www.geophys.washington.edu/tsunami/specialized/research/research.html
How big do they get?
In the open ocean tsunamis may appear very small with a height of less than 1
meter (3 feet). Tsunamis will sometimes go undetected until they approach
shallow waters along a coast. These waves have a very large wavelength (up to
several hundred miles) that is a function of the depth of the water where they
were formed. Although these waves have a small height, there is a tremendous
amount of energy associated with them. As a result of this huge amount of
energy, these waves can become gigantic as they approach shallow water. Their
height, as they crash upon the shore, depends on the underwater surface
features. They can be as high as 30 m (100 feet) or more. In 1737 , a huge wave
estimated to be 64m (210 feet) in height hit Cape Lopatka, Kamchatka (NE
Russia). The largest Tsunami ever recorded occurred in July of 1958 in Lituya
Bay, Alaska. A huge rock and ice fall sent water surging up to a high water
mark of 500m (1640 feet). It's no wonder that these waves can cause such
massive destruction and loss of life.
www.frontiernet.net/~docbob/waves.htm
Tsunami from Asteroid/Comet Impacts
We have begun a systematic study of tsunami produced by the impacts of
asteroids and comets on Earth. As the first phase of this work, we have looked
at tsunami produced by the impacts of moderately large asteroids, 5-6 km in
diameter, in the middle of the large ocean basins. This work is to identify
coastal areas that are most susceptible to impact tsunami. We find that areas
with gradual continental shelves such as the British Isles in Europe and
Florida in the United States are less susceptible to impact tsunami while
regions with little continental shelf are the more exposed. Gradual continental
shelves tend to reflect the tsunami back into the ocean. An asteroid 5-6
kilometers in diameter hitting in mid Atlantic would produce tsunami that would
travel all the way to the Appalachian Mountains in the upper two-thirds of the
United States; e.g., Washington, D.C. would be washed out. In Florida, the
damage would be much less except in the area from West Palm Beach through Ft.
Lauderdale to Palm Beach where a deepwater shipping channel would funnel the
tsunami energy to shore. In Europe, the most susceptible area is the Spain-
Portugal peninsula, which has very little continental shelf. In retrospect,
this result is not surprising as this peninsula has been subject to earthquake
tsunami during the last few hundred years. An asteroid 5-6 kilometers in
diameter impacting between Hawaii and the West Coast would wash out the coastal
cities. The area between Los Angelos and San Diego is particularly vulnerable.
This same impact would produce tsunami that would cover most of the land area
of Oahu, the most populous Hawaiian island.
www.aas.org/publications/baas/v29n5/aas191/abs/S033007.html
www.tsunami.org/links.htm#Movies,%20Animations,%20and%20Simulations
www.pbs.org/wnet/savageseas/multimedia/wavemachine.html
dsc.discovery.com/news/briefs/20030602/tsunami.html
neat.jpl.nasa.gov/
---
<.>
.....................
Szwecja jest krajem o wysokiej ilosc ofiar katastrofy w Azji
www.dn.se/
www.svd.se/
