How does earthquake cause tsunami

Then recorded are a few waves a little larger than normal followed by several much larger waves. In many tsunami events, the shoreline is pounded by repeated large waves. Tsunami Geology - What Causes a Tsunami? Article by: Hobart M.

Tsunami generation images by USGS. All images shown above are by USGS. Find Other Topics on Geology. Maps Volcanoes World Maps. Map of the Oceans. Phytoplankton Blooms. How did the Hawaiian Islands Form? Arctic Ocean Seafloor Map.

Deepest Part of the Ocean. Storm Surge. What Causes a Tsunami? Rocks: Galleries of igneous, sedimentary and metamorphic rock photos with descriptions. The waves can travel great distances from the source region, spreading destruction along their path.

For example, the Great Chilean tsunami was generated by a magnitude 9. Its waves were destructive not only in Chile, but also as far away as Hawaii, Japan and elsewhere in the Pacific. It should be noted that not all earthquakes generate tsunamis. Usually, it takes an earthquake with a Richter magnitude exceeding 7.

There are subduction zones with associated deep-sea trenches off Chile, Alaska, Japan, and Indonesia, for example, that have produced large earthquakes and devastating tsunamis, many of which caused damage and loss of life in the Hawaiian Islands. Part of the seafloor snaps upward as the tension is released.

The entire column of seawater is pushed toward the surface, creating an enormous bulge. As the water flattens out, giant ripples race outward. Landslides, Volcanic Eruptions, MeteoritesSubmarine landslides, which often occur during a large earthquake, can create a tsunami. During a submarine landslide, the equilibrium sea level is altered by sediment moving along the sea floor.

Gravitational forces then propagate the tsunami given the initial perturbation of the sea level. Similarly, a violent marine volcanic eruption can create an impulsive force that displaces the water column and generates a tsunami.