Tsunami Locations & Occurrences

We are living on a geologically active planet. Earthquakes and tsunamis have always been occurring. The largest number of earthquakes occur around the rim of the Pacific Ocean associated with a series of volcanoes and deep-ocean trenches known as the "Ring of Fire".

As a result, the largest source region for tsunamis is in the Pacific Ocean with 71% of all occurrences.

Within the main Pacific Ocean basin, tsunamis generated in the tropics, while locally devastating, tend to weaken rapidly with distance.

However, tsunamis generated in the North Pacific Ocean and along the Pacific Coast of South America often travel throughout the Pacific leaving death and destruction in their wake.

The remaining occurrences of tsunamis happen in the Mediterranean Sea (15%), Caribbean Sea and Atlantic Ocean (7%), Indian Ocean (6%), and finally the Black Sea (1%). Of all tsunamis, 83% are produced directly by earthquakes.

Landslides/rockslides (or icefalls) into water or landslides under the ocean surface can generate sufficient displacement of water to produce tsunamis as well.

One such rockfall occurred on July 9, 1958 in Lituya Bay, Alaska. An earthquake triggered a 40 million cubic yard rock fell at the head of the bay.

Due to the confines of the bay, the resulting tsunami wave reached a height of 1,720 feet (520 meters) on the opposite side of the inlet. Down the inlet itself, the initial wave reached a height of 600 feet (120 meter) moving toward the ocean at 100 mph (160 km/h).

This was not the only time this type of event occurred in this bay. There are at least four other instances of a landslide causing a tsunami in Lituya Bay (1936, 1900, 1874, 1854).

While the magnitude of the 1959 tsunami event has not been matched since it occurred over 50 years ago, 6% of all worldwide tsunamis are generated by earthquake induced landslides.

While also rare, volcanoes can produce devastating tsunamis. One of the most deadliest tsunami events was generated by the Krakatoa volcano eruption in 1883.

World's Deadliest Tsunamis 1650 B.C to 2010 A. D.
From National Centers for Environmental Information
Deaths Year Location Ocean Basin Cause
227,899 2004 N. Sumatra Indian 9.1M Earthquake
50,000 1755 Portugal, Lisbon Atlantic 8.5M Earthquake
34417 1883 Indonesia, Krakatoa Indian Volcano
31,000 1498 Japan, Enshunada Sea Pacific 8.3M Earthquake
27,122 1896 Japan, Sanriku Pacific 8.3M Earthquake
25,000 1868 Chile, Northern Pacific 8.5M Earthquake
18,482 2011 Japan, Honshu Island Pacific 9.0M Earthquake
14,524 1792 Japan, Shimabara Bay, Kyushu Island Pacific 6.4M Earthquake
13,486 1771 Japan, Ryukyu Island Pacific 7.4M Earthquake
8,000 1586 Japan, Ise Bay Pacific 8.2M Earthquake
6,800 1976 Phillippines, Moro Gulf Pacific 8.0M Earthquake
5,233 1703 Japan, Off SW Boso Peninsula Pacific 8.2M Earthquake
5,000 1707 Japan, Nankaido Pacific 8.4M Earthquake
5,000 1687 Puro, South Peru Pacific 8.5M Earthquake
5,000 1611 Japan, Sanriku Pacific 8.1M Earthquake
5,000 1605 Japan, Nankaido Pacific 7.9M Earthquake
5,000 365 Greece, Crete Mediterranean 8.0M Earthquake
4,800 1746 Peru, Lima Pacific 8.0M Earthquake
4,000 1792 Russia, Kamchatka Pacific 9.0M Earthquake
4,000 1792 Pakistan, Makran Coast Indian 8.0M Earthquake
3,022 1933 Japan, Sanriku Pacific 8.4M Earthquake
3,000 1854 Japan, Nankaido Pacific 8.4M Earthquake