Tsunamis
By: Janna • Essay • 715 Words • January 17, 2010 • 820 Views
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On December 26, 2005, an earthquake occurred off the coast of Sumatra, an island in the Indian Ocean. The earthquake was a massive, underwater event that triggered a huge tsunami which devastated a huge amount of land in the surrounding areas. There was little warning to the surrounding populations, resulting in extensive property damage, as well as large amounts of human casualties in the area. Geologists have since studied the effects of the quake and resulting tsunami in hopes of developing some early warning system to prevent the loss of life that occurred in Sri Lanka, Sumatra, and other areas.
The quake occurred at the boundaries of the India Plate and the Burma Plate, roughly 150 miles off the coast of Sumatra. This boundary is a convergent boundary, with the India Plate subducting under the Burma Plate. The constant pushing of these two plates against each other caused the eventual build-up of enormous amounts of energy. On December 26, the two plates slipped past each other, causing a 600 mile-long rupture of the seabed. The rupture displaced the seafloor about 10 yards horizontally, and several yards vertically. The resulting displacement of trillions of tons of water is what actually caused the huge waves.
The earthquake, whose epicenter was about 150 miles off the Western coast of Sumatra, was one of the largest in recorded history; an astonishing 9.3 magnitude. The quake was estimated to have released the equivalent of 23,000 Hiroshima-type atomic bombs№. Since the quake occurred 150 miles away from any landmass, little or no damage resulted from the actual earthquake, although people as far away as Thailand we wakened from their sleep .
A tsunami is formed by a displacement of water, either from a landslide, volcanic eruption, or as in this case, the slippage of two tectonic plates against each other. The displacement of water then creates energy waves that emanate from the source of the displacement and travel, gaining speed and energy, until they are stopped by some mass- usually land .
This particular tsunami affected areas thousands of miles from the epicenter of the quake. The most affected areas were on the island of Sumatra. The first waves reached the island less than a half hour after the quake, partly because the tsunami was estimated to travel upwards of 800 MPH through the Indian Ocean. The waves that struck land were measured at 10 to 15 meters on Sumatra. Other areas affected were Thailand,