Tsunami

The world was stunned on December The world was stunned on December 26, 2004 when the powerful Sumatra- 26, 2004 when the powerful Sumatra-

Andaman earthquake triggered Andaman earthquake triggered tsunamis that demolished many coastal tsunamis that demolished many coastal

areas of South and Southeast Asia.areas of South and Southeast Asia.

TsunamiTsunami Tsunami is a Japanese word meaning Tsunami is a Japanese word meaning

“harbor wave”.“harbor wave”.

The word describes the violent The word describes the violent motion of water in a lake or ocean motion of water in a lake or ocean after a major disturbance, such as an after a major disturbance, such as an calving icebergs, landslides, calving icebergs, landslides, volcanoes, meteorites and volcanoes, meteorites and earthquake.earthquake.

Water displacement causes huge Water displacement causes huge waves barely noticeable on the waves barely noticeable on the ocean’s surface. These waves can ocean’s surface. These waves can move up to 500 mph, and be only 1 move up to 500 mph, and be only 1 foot high on the ocean’s surface.foot high on the ocean’s surface.

As waves get closer to shore, they As waves get closer to shore, they come in contact with the continental come in contact with the continental shelf and turn into massive, shelf and turn into massive, destructive waves crashing onto destructive waves crashing onto beaches and oceanfront properties. beaches and oceanfront properties.

Taiwan

The Indian Ocean tsunami was The Indian Ocean tsunami was caused by an undersea caused by an undersea

(submarine) earthquake that (submarine) earthquake that occurred on December 26, 2004. occurred on December 26, 2004. The epicenter was off the west The epicenter was off the west coast of Sumatra, an island in coast of Sumatra, an island in

Indonesia.Indonesia.

Estimates now say the tsunami’s destruction killed Estimates now say the tsunami’s destruction killed more than 225,000 people in eleven countries, and more than 225,000 people in eleven countries, and inundated coastal communities with waves up to 30 inundated coastal communities with waves up to 30

meters (100 feet) high. Indonesia, Sri Lanka, India and meters (100 feet) high. Indonesia, Sri Lanka, India and Thailand were hit the hardest. Thailand were hit the hardest.

It was one of the deadliest natural disasters in history, It was one of the deadliest natural disasters in history, probably the worst tsunami ever recorded (records go probably the worst tsunami ever recorded (records go

back to the late 1400’s).back to the late 1400’s).

The earthquake was caused by subduction – a subduction zone is an area where two tectonic plates meet and move towards one another, with one sliding underneath the other

and moving down into the mantle.

With a magnitude of between 9.1 and 9.3, it is the second With a magnitude of between 9.1 and 9.3, it is the second largest earthquake ever recorded on a seismograph. This largest earthquake ever recorded on a seismograph. This

earthquake had the longest duration of faulting ever earthquake had the longest duration of faulting ever observed, between 8.3 and 10 minutes. It caused the entire observed, between 8.3 and 10 minutes. It caused the entire

planet to vibrate as much as 1 cm (0.5 inches) and planet to vibrate as much as 1 cm (0.5 inches) and triggered other earthquakes as far away as Alaska.triggered other earthquakes as far away as Alaska.

Richter MagnitudesRichter MagnitudesRichterRichter

Approximate Approximate Magnitude Magnitude

Approximate Approximate TNT forTNT forSeismic Seismic

Energy Yield Energy Yield

Example Example

9.3 9.3 114 gigatons 114 gigatons Indian Ocean Indian Ocean Earthquake Earthquake 20042004

9.59.5 178 gigatons 178 gigatons Valdivia Valdivia Earthquake, Earthquake, Chile 1960Chile 1960

10.010.0 1 teraton1 teraton Never recordedNever recorded

One gigaton is about 2750 One gigaton is about 2750 Empire State Buildings, or about Empire State Buildings, or about 142 million African elephants. 142 million African elephants.

Banda Aceh, Indonesia, island of SumatraBefore the 2004 tsunami

Banda Aceh, Indonesia, island of SumatraAfter the 2004 tsunami

http://www.pbs.org/wgbh/nova/tsunami/anatomy.html

Interactive 2004 tsunami website

http://www.solcomhouse.com/tsunamis.htm retrieved 12/11/08

http://www.bepast.org/docs/photos/Tsunami/ retrieved 12/10/08

https://www.spiegel.de/international/spiegel/0,1518,grossbild-426498-392362,00.html

retrieved 12/11/08

http://www.iari.res.in/tsunami/page1.html retrieved 12/11/08