Tsunami! What happened & why
2004 Indian Ocean Earthquake • Undersea earthquake • Magnitude 9.0 (Moment magnitude scale) NOAA
Epicenter 150 KM west of Sumatra http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake
Occurred along the subduction zone where the Indian dives under the Eurasian Plate http://www.nps.gov/prsf/geology/images/plates.gif
Facts • The earthquake came just three days after a magnitude 8.1 earthquake in an uninhabited region west of New Zealand • Possible connection between these two earthquakes • Possibility of a seismic chain reaction across neighboring plates has also been considered
Facts • Total energy released by a magnitude 9.0 earthquake exceeds the total amount of energy consumed in the U.S. in one month • Massive release of energy and shift in mass insignificantly altered the Earth's rotation
A tsunami (pronounced soo-NAA-mee) is a series of waves (called a "wave train") generated in a body of water by a pulsating or abrupt disturbance that vertically displaces the water column.
Tsunami's are also mistakenly referred to as tidal waves as they often resemble a tide that keeps rising, rather than cresting waves when they reach shore. However, as they are not actually related to tides the term may be misleading, and its use is discouraged by scientists.
Tsunamis are created when: • Seafloor quickly changes shape • Water is displaced • Waves are formed as the displaced water mass, which is affected gravity, tries to move back Anthony Liekens 15:30, 28 Dec 2004 (UTC)
Characteristics • Move at high speeds • Can travel enormous distances with little energy loss • Can cause damage thousands of miles from its origin • May be several hours between its creation and its impact on the coast
Warning Systems Many countries around the Pacific, including Hawaii, have warning systems and evacuation procedures in the event of a serious tsunami.
Effects of Tsunamis • Destruction of human life (100,000+) • Destruction of property • Spread of disease • Destruction of ecosystems