What Causes A Tsunami?
Most commonly, an earthquake under the ocean floor, can cause Tsunami's. Pressures and forces build up for hundreds, sometimes even thousands of years. Geology.com states that these incredibly strong forces are called subduction zones, an area where an oceanic plate is being forced down into the mantle by plate tectonic forces. The friction between the subducting plate and overriding plate is enormous. This friction prevents a slow and steady rate of subduction and instead the two plates become "stuck".
The Plate that is stuck continues to descend into the mantle that motion will cause a slow distortion of the overriding plate. Power and pressure builds up over long periods of time.
The energy collects and builds up in the overriding plate until it exceeds the frictional forces between the two stuck plates. When that happens, the overriding plate snaps back into an uncontrolled position. This sudden motion is the cause of a tsunami. The water lying above the subduction zone is thrust, causing the enormous wave.
The sudden thrust causes the newly formed giant waves to travel from where the earthquake occurred. The water travels in a ripple effect, rushing swiftly in every direction. If land is in the way of the tsunami, the shoreline will suddenly lower, a sure sign that a wave of destruction is coming.
The Earthquake Specific to Sumatra
Built up forces beneath the surface of the Indian Ocean were suddenly released, causing a catastrophic tsunami to blast across the ocean at the speed of a jet airliner. The 9.3 earthquake that hit Sumatra was estimated, by the U.S. Geological Survey (USGS), to have released the energy of 23,000 Hiroshima-type atomic bombs. An estimated 230,210 people were killed in the devastation.
According to National Geographic, The earthquake was a result of the sliding of the portion of the Earth's crust known as the India plate under the section called the Burma plate. The result of the sliding plates was a rupture that the USGS estimates was more than 600 miles long, displacing the seafloor above the rupture by almost 10 years horizontally and several years vertically. Trillions of rocks along the hundreds of miles of sea floor, caused an earthquake. The largest magnitude earthquake in 40 years.
According to National Geographic, The earthquake was a result of the sliding of the portion of the Earth's crust known as the India plate under the section called the Burma plate. The result of the sliding plates was a rupture that the USGS estimates was more than 600 miles long, displacing the seafloor above the rupture by almost 10 years horizontally and several years vertically. Trillions of rocks along the hundreds of miles of sea floor, caused an earthquake. The largest magnitude earthquake in 40 years.
Special thanks to Geology.com, National Geographic & the U.S Geological Survey!
Author unknown (October 28, 2010) The Deadliest Tsunami in History? National Geographical News. Retrieved from http://news.nationalgeographic.com/news/2004/12/1227_041226_tsunami.html
Author unknown (NA) Tsunami Geology-What causes a tsunami? Geology.com-News and information about geology. Retrieved from http://geology.com/articles/tsunami-geology.shtml
Bruce Jaffe, Eric Geist & Helen Gibbons (December 2004) Indian Ocean Earthquake Triggers Deadly Tsunami. USGS-science for a changing world. Retrieved from http://soundwaves.usgs.gov/2005/01/
Author unknown (NA) Tsunami Geology-What causes a tsunami? Geology.com-News and information about geology. Retrieved from http://geology.com/articles/tsunami-geology.shtml
Bruce Jaffe, Eric Geist & Helen Gibbons (December 2004) Indian Ocean Earthquake Triggers Deadly Tsunami. USGS-science for a changing world. Retrieved from http://soundwaves.usgs.gov/2005/01/