Tsunami
Japanese term (literally meaning 'big wave') now generally used for an unusual, very large wave or series of waves. Tsunamis are generated either by submarine earthquakes, by landslides or by effects of volcanic eruptions (such as the collapse of a caldera in the sea). Tsunamis have long wavelengths and small wave heights on the open sea. As water depth decreases near land the wavelength diminishes and the wave height increases dramatically which may lead to catastrophic flooding of coastal areas. Tsunamis may deceive coastal residents in that a wave trough may a arrive before the first wave crest.
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Escaping a tsunami on Stromboli. Photo: © Philippe Guillemin Map illustrating an assumed mode of propagation of the 2002 tsunami on Stromboli. |
