Tsunamis Fast Facts

Here is a look at tsunamis.

Tsunamis are formed by a displacement of water - a landslide, earthquake, volcanic eruption, or slippage of the boundary between two of the earth's tectonic plates - slabs of rock 50 to 650 feet (15 to 200 meters) thick that carry the Earth's continents and seas on an underground ocean of much hotter, semi-solid material.

Tsunamis can travel more than 500 mph (800 k/ph) at the deepest point of the water, but slow as they near the shore, eventually hitting the shore at 20 to 30 mph (32 to 48 k/ph). The energy of the wave's speed is transferred to height and sheer force as it nears shore.

November 1, 1755 - An estimated 60,000 people are killed when an earthquake strikes Lisbon, Portugal, and causes a tsunami.

August 27, 1883 - An estimated 36,000 people are killed when the Krakatau volcano erupts, causing a tsunami in the Indonesian islands of Java and Sumatra.

June 15, 1896 - An estimated 28,000 people are killed when an 8.5-magnitude earthquake strikes Sanriku, Japan, causing a tsunami.

December 28, 1908 - An estimated 70,000-100,000 people are killed when a 7.2-magnitude earthquake strikes Messina, Italy, and causes a tsunami in the Straights of Messina.