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Dịch qua Tiếng Việt
Tsunamis, whose name derives from the Japanese expression for "high wave in a
harbour", are giant sea waves. These waves are quite different from storm surges. They are
also referred to by the general public as tidal waves although they have nothing to do with
tides. Scientists often refer to them as seismic sea waves, which is far more appropriate
because they are often the result of undersea seismic activity.
Tsunamis can be caused when the sea floor suddenly moves, during an underwater
earthquake or volcano, and the water above the moving earth is suddenly displaced. This
sudden shift of water sets off a series of waves. These waves can travel great distances, at
speeds close to 700 kilometres per hour. In the open ocean, tsunami waves are not very
high, often no more than one or two metres. It is when they hit the shallow waters near the
coast that they increase in height, possibly up to 40 metres.