TSUNAMIS (SOMETIMES CALLED seismic sea waves) are large sea waves that are created by underwater earthquakes, volcanic eruptions, or even nonseis-mic events such as landslides and meteorite impacts. Tsunamis are also known as tidal waves, even though this is a misnomer because the waves have nothing to do with tides. The word tsunami is a Japanese word meaning “harbor wave.” Tsunamis are not easily seen on the open water, as they have extremely long wavelengths on the order of tens of kilometers. The speed of the wave is directly related to the depth of the water; therefore, as the water depth decreases, the tsunami moves slower. As the waves propagate toward the coast, the speed will decrease, but the amplitude or the height of the ...