Tsunamis open ocean waves caused by: Tsunamis are not tidal waves. (The tides are caused mainly by the moon’s gravity and are not related to tsunamis).

Indonesia tsunami (2004) caused by a M 9.0 quake along a subduction zone (a 750-mile section of the fault moved 50 feet!)

on the open ocean: tsunamis have wave heights of 3 ft and wavelengths of 60 miles Speed: +500 mph

World propagation of tsunami:

The height and the distance inland that tsunamis travel depends on the topography and the shape of coastline.

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Tsunami warning Sign: in some cases, tsunamis are preceded by a fall in sea level

Before After Before and after tsunami satellite images of Indonesian coastline Survivor stories

Most people that died in the Asian tsunami drowned or were killed by floating debris. However, after the immediate disaster other hazards became apparent:

Since there may be several minutes between waves, survivor are often swept back out to sea

Tsunami relief efforts: relief aid for the tsunami victims came from all parts of the world former US Presidents Bush and Clinton are in charge of United Nations joint tsunami relief effort Some problems with providing relief aid:

Tsunami warning systems are composed of 3 types of devices:

Pacific Ocean Tsunami warning system

Deep Ocean Tsunameter: uses a on the bottom of the ocean to detect passing tsunami waves

Indian Ocean tsunami warning system: USGS tsunami hazard page:

The highest risk area for tsunamis in the US is along the west coast

Tsunami deposits (sand) along the west coast of US

Hawaiian Islands are volcanic. As these volcanoes cool they become weak and are subject to ‘flank collapse’. When geologists first mapped the ocean floor around Hawaii they found evidence for these collapses. Steven Earle, Malaspina University-College, Geology Department

Last known collapse: 110,000 years ago A tsunami generated in this way today would devastate coastal areas around the Pacific.

The Canary Islands are volcanic islands similar to Hawaii. Island flank collapse would threaten coastal areas around the Atlantic, including cities along US East Coast. The last known flank collapse in Canary Islands:

Earth Sciences, Ga. Tech Estimated tsunami travel time from Canary Islands to New York: