...are not caused by tides

University of Michigan.
A tsunami is a kind of wave in the ocean. The waves of tsunami radiate out from a source area when a large volume of seawater is suddenly displaced. Causes of rapid displacement of seawater include large earthquakes that move ground, major submarine slides, exploding underwater volcanoes, and large asteroid impacts.

From a source area, tsunami radiate out across the ocean like giant ripples in a pond the size of the ocean. The ring-shaped ripples are distorted by the shape of the seafloor underneath the path of the moving waves. Tsunami can travel across entire oceans in a matter of hours.

We are most familiar with the destruction that large tsunami cause when they strike land. The crests of large tsunami can cause sea water to move far inland and take people by surprise. The energy contained in the moving water can move buildings like toys.

So what does this wave look like in the open ocean? Not much. If you were on a ship when a tsunami passed, you would not notice because the wave height would be less than 2 meters. Wind waves in the ocean would be much larger.

Testing out the Tsunami Research Tank
See the video of our tank in action.
Image from the Ocean Institute
All that you can do at OI

To think about:
If tsunami look very wimpy at sea, why do they grow into monsters close to shore? Where are they hiding all that destructive energy?

At the Ocean Institute
Visitors to the Ocean Institute generate tsunamis by simulating underwater landslides in the Institute's Tsunami Research Tank.

Where to find more information:

Tsunami Quickguide
Quick description of tsunami and link to a variety of related resources, including information about the recent Indian Ocean tsunami of 2004.
Earthguide, Scripps Institution of Oceanography

California Tsunami Models and Animations
What might happen if there were underwater landslides and/or earthquake offshore California? See the model results.
USC Tsunami Research Group

Waves of Destruction: Tsunami
About tsunami.
Savage Earth, PBS Online

Explains the reasons for the killer tsunami that struck Papua New Guinea in 1998.
The Why Files, University of Wisconsin

Descriptive Model of the July 17, 1998 Papua New Guinea Tsuanami
Explains the reasons for this killer tsunami. Includes animations showing the results of model simulations.
Western Region Coastal & Marine Geology, U.S. Geological Survey

West Coast & Alaska Tsunami Warning Center
"The West Coast/Alaska Tsunami Warning Center objectives are to rapidly locate and size major earthquakes in the Pacific basin, determine their tsunami potential, predict tsunami arrival times and, when possible, runup on the coast, and provide timely and effective tsunami information and warning bulletins for the Pacific coastal populations of California, Oregon, Washington, British Columbia, and Alaska."
National Weather Service, NOAA

Pacific Tsunami Warning Center
"Established in 1949, the Pacific Tsunami Warning Center (PTWC) in Ewa Beach, Hawai`i, provides warnings for teletsunamis to most countries in the Pacific Basin as well as to Hawai`i and all other US interests in the Pacific outside of Alaska and the US West Coast. Those areas are served by the West Coast / Alaska Tsunami Warning Center (WC/ATWC) in Palmer, Alaska. PTWC is also the warning center for Hawai`i's local and regional tsunamis."
National Weather Service, NOAA

USC Tsunami Research Group
"A new USC study shows that tsunamis - triggered by earthquakes and underwater slides - could threaten Southern California’s coast."
By Bob Calverley, USC News

Southern California Earthquake Center
About earthquakes in southern California.

Recent Earthquake Activity in the USA
Recent earthquakes reports aroud the U.S.

Broadband Seismic Data Collection Center
Recent earthquakes in southern California.
Scripps Institution of Oceanography

This Dynamic Earth: The Story of Plate Tectonics
Online reference about plate tectonics.
By Kious and Tilling, U.S. Geological Survey

Produced in collaboration with Scripps Institution of Oceanography.
Website by Earthguide.

© 2003-2004 by the Ocean Institute
and the Regents of the University of California.
All rights reserved.
Last modifed Monday, December 10, 2004