Tuesday, 29 September 2009

Tsunami in Samoa 2009 Tsunami warning California

New Delhi, Sept 30, 2009: Tsunami in Samoa 2009 Tsunami warning California. Several villages have been washed away in the latest tsunami in Samoa and American Samoa. Several dozen people are already dead in the earthquake and the following tsunami that befell in the area.

Meanwhile there are reports that tsunami warning has been withdrawn from California. It was reported earlier that a tsunami warning had been issued in California following 8.0 strong earthquake in Samoa islands.

Tsunami is a set of ocean waves caused by any large, abrupt disturbance of the sea-surface. If the disturbance is close to the coastline, local tsunamis can demolish coastal communities within minutes. A very large disturbance can cause local devastation AND export tsunami destruction thousands of miles away.

The word tsunami is a Japanese word, represented by two characters: tsu, meaning, "harbor", and nami meaning, "wave". Tsunamis rank high on the scale of natural disasters.

Since 1850 alone, tsunamis have been responsible for the loss of over 420,000 lives and billions of dollars of damage to coastal structures and habitats. Most of these casualties were caused by local tsunamis that occur about once per year somewhere in the world.

For example, the December 26, 2004, tsunami killed about 130,000 people close to the earthquake and about 58,000 people on distant shores. Predicting when and where the next tsunami will strike is currently impossible. Once the tsunami is generated, forecasting tsunami arrival and impact is possible through modeling and measurement technologies.

What To Do following tsunamio? - Simulations show the initial tsunami wave from the 1700 event reached the coast in 20 to 30 minutes - so time is limited. Geologic history showed waves with this event were as high as 30 feet. So you must get at least that high above sea level.

To top it off, the earthquake will also result in the coastal area subsiding as much as six feet, meaning the ground and roadways will likely be very uneven, and you are now that much lower to sea level. Since the roads will be in pieces, evacuation must be on foot. Another form of evacuation is vertical evacuation into a sturdy building of at least three stories and climb to at least the third story.

Other area earthquake faults could produce such strong violent quakes, such as the Seattle fault that produced a tsunami in Puget Sound about 1100 years ago. Yet, the most likely source for a local tsunami is the Cascadia Subduction Zone off our coast.

A Distant Source - The perimeter of the Pacific Ocean Basin, nicknamed the Ring of Fire, has a number of earthquake sources that can produce strong earthquakes of 7.0 magnitude or greater. During the 20th century, there were three 9.0 magnitude or greater quakes, the last was the 1964 Alaskan quake of 9.2 magnitude that produced a tsunami throughout the Pacific Basin. These kind of earthquakes permit a lead time of hours before their subsequent tsunami reaches the Washington coastline. Tsunamis from distant locations like Japan or Chile will take over 10 hours to get here, while from Alaska, only three to six hours.

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