I have heard the news earlier today and iit is really hard to fathom the enormous power of nature. This tsunami has taken more than 13,773 lives at present count and the count is rising.
The tsunami waves were triggered by an 8.9 magnitude underwater earthquake off the Indonesian island of Sumatra, rearing up into walls of water as high as 10 meters (30 feet) as they hit shallow coastlines in south and south-east Asia.
The earthquake hit at 6:58 a.m.; the tsunami came as much as 2 1/2 hours later, without warning, on a morning of crystal blue skies. Sunbathers and snorkelers, cars and cottages, fishing boats and even a lighthouse were swept away.
I am seeing now that the quake was measured to be 9.0. It is the worst recorded in over 40 years but not surprisingly it was another product of the “Ring of Fire”.
I did a little research on tsunamis and found that they can be generated a number of ways… Earthquakes, landslides, volcanic eruptions, explosions, and even the impact of cosmic bodies, such as meteorites, can generate tsunamis. I think that the most interesting one and probably the most common one is the earthquake generated tsunami. Here are some facts on the phenomena and following are some tips to survive them although they seem a little naive.
Tsunamis can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Tectonic earthquakes are a particular kind of earthquake that are associated with the earth’s crustal deformation; when these earthquakes occur beneath the sea, the water above the deformed area is displaced from its equilibrium position. Waves are formed as the displaced water mass, which acts under the influence of gravity, attempts to regain its equilibrium. When large areas of the sea floor elevate or subside, a tsunami can be created.
Large vertical movements of the earth’s crust can occur at plate boundaries. Plates interact along these boundaries called faults. Around the margins of the Pacific Ocean, for example, denser oceanic plates slip under continental plates in a process known as subduction. Subduction earthquakes are particularly effective in generating tsunamis.
This simulation (2 MB) of the 1993 Hokkaido earthquake-generated tsunami, developed by Takeyuki Takahashi of the Disaster Control Research Center, Tohoku University, Japan, shows the initial water-surface profile over the source area and the subsequent wave propagation away from the source. Areas in blue represent a water surface that is lower than the mean water level, while areas in red represent an elevated water surface. The initial water-surface profile, as shown in this image, reflects a large, long uplifted area of the sea floor lying to the west (left) of Okushiri Island, with a much smaller subsided area immediately adjacent to the southwest corner of Okushiri.
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