Information about Tsunamis

Tsunami is a Japanese word meaning "harbor wave". Since 1819, about 40 tsunamis have struck the Hawaiian Islands!



How they form

A tsunami is a sea wave generated by an undersea earthquake or possibly an undersea landslide or volcanic eruption. When the ocean floor is tilted or offset during an earthquake, a set of waves is created. Most tsunamis originate along the Ring of Fire, a zone of volcanoes and seismic activity, 32,500 km (24,000 mi) long, that encircles the Pacific Ocean. Since 1819, about 40 tsunamis have struck the Hawaiian Islands.

A tsunami can have wavelengths, or widths, of 100 to 200 km (60 to 120 mi), and may travel hundreds of kilometers across the deep ocean, reaching speeds of about 725 to 800 km/hr (about 450 to 500 mph). Upon entering shallow coastal waters, the wave, which may have been only about half a meter


Facts

Tsunamis that strike coastal locations in the Pacific Ocean Basin are most always caused by earthquakes. These earthquakes might occur far away or near where you live.

Some tsunamis can be very large. In coastal areas their height can be as great as 30 feet or more (100 feet in extreme cases), and they can move inland several hundred feet.

All low-lying coastal areas can be struck by tsunamis.

A tsunami consists of a series of waves. Often the first wave may not be the largest. The danger from a tsunami can last for several hours after the arrival of the first wave.

Tsunamis can move faster than a person can run. Sometimes a tsunami causes the water near the shore to recede, exposing the ocean floor.

The force of some tsunamis is enormous. Large rocks weighing several tons along with boats and other debris can be moved inland hundreds of feet by tsunami wave activity. Homes and other buildings are destroyed. All this material and water move with great force and can kill or injure people.

Tsunamis can occur at any time, day or night.

Tsunamis can travel up rivers and streams that lead to the ocean.

This information taken from: http://www.oars.utk.edu/volweb/Schools/sumnercs/ellism/index2.htm

UPDATE 2/18/05::::: maybe it is just my computer, but I just checked the link again and it appears to be a page not found now..





For more information, or to see a 'bird's eye view ' picture, is on this link that shows you an actual Tsunami. Kind of frightening if you think about being on the ground looking at that...

Made me more aware of the natural disasters that affect other countries.

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