UNIT 4. NATURAL DISASTERSListening

Listen and fill in the blanks.

    Tsunamis, name derives from the Japanese expression for “high wave in a ”, are giant sea waves. These waves are quite different from storm surges. They are also referred to by the general public as 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 seismic activity.
Tsunamis can be caused when the sea suddenly moves, during an underwater or volcano, and the water above the moving earth is suddenly displaced. This sudden of water sets off a series of waves. These waves can travel great distances, at speeds close to 700 kilometers per hour. In the open , tsunami waves are not very high, often no more than one or two meters. It is when they hit the waters near the coast that they increase in , possibly up to 40 meters.