|Tsunamis (also known as tidal
waves or seismic seawaves) are large water waves that form when parts of
the sea floor are displaced rapidly by volcanic eruptions, submarine
landslides, or underwater earthquakes (Stein,
pp. 19-20). Tsunamis are not noticeable as they cross the
ocean, but can be amplified tremendously as they approach the shore.
The geologic cross-section on the right presents hypothetical conditions that can result in a tsunami. It illustrates a earthquake caused by a thrust fault on the sea floor that rapidly elevates a portion of the sea floor. A large volume of the sea is displaced, and a tsunami is set into motion. Large waves radiate from the epicenter of the earthquake and move radially in all directions. The waves move at a velocity in the range of 300 to 500 miles per hour (500 to 800 km per hour) until they reach land. As they approach land, the tsunami wave amplifies dramatically and potentially causes destruction along shorelines that are encountered.
Some Useful Links
The above discussion provides basic information and illustrations for tsunamis. To further explore this subject, excellent publications or the resources of the internet can be explored. Following are some hyperlinks that can further assist with the evaluation and description of tsunamis:
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