Tsunamis - 6 of 7

Tsunamis FAQs - 7 Found

Where have tsunamis occurred historically?

East Coast: Historically, no tsunamis have been generated on the east coast, a consequence of the low level of seismic activity and the lack of vertical fault displacement. No tsunami occurred during the Charleston, South Carolina, earthquake of 1886, one of the largest earthquakes in the United States. In addition, none of the tsunamis occurring in the Atlantic Ocean region has significantly affected the east coast of the United States. The only tsunami known to have been recorded on the Atlantic Coast of the United States was generated by an earthquake off the Burin Peninsula of Newfoundland on November 18, 1929; it caused a wave height of 1 foot.

West Coast: Tsunamis generated byearthquakes in South America and the Aleutian-Alaskan region have posed a greater hazard to the west coast of the United States than locally generated tsunamis. For example, the 1946 Aleutian tsunami produced waves heights of 12 to 16 feet at Half Moon Bay, Muir Beach, Arena Cove, and Santa Cruz, California. The 1960 Chilean tsunami produced wave heights of 12 feet at Crescent City, California. The 1964 Alaskan tsunami generated waves of more than 20 feet at Crescent City, California, where it caused $7.5 million in damage and 11 deaths. It also produced waves ranging from 10 to 16 feet along parts of the California, Oregon, and Washington coasts. In contrast, for example, the 1906 San Francisco, California, earthquake produced local tsunami waves of only about 2 inches. The largest known locally generated tsunami on the west coast was caused by the 1927 Point Arguello, California, earthquake that produced waves of about 7 feet in the nearby coastal area.

Alaska: The combination of seismic activity in the Aleutian-Alaskan trench where the Pacific and North American tectonic plates collide and the vertical displacements of faults make this region of Alaska a source of tsunamis. The earliest recorded tsunami in this region was in 1788. Four major tsunamis were generated in 1946, 1957, 1964, and 1965; the 1964 Alaskan tsunami caused over $80 million in damage and killed 107 people.

Hawaii: The Hawaiian Islands have experienced many destructive tsunamis because of their location in the Pacific Ocean where about 90 percent of all recorded tsunamis take place. Since 1819, more than 100 locally and distantly generated tsunamis have been recorded in the Hawaiian Islands with 16 of them causing significant damage. More than one-half of all tsunamis recorded in the Hawaiian Islands were generated in the Kuril-Kamchatka-Aleutian regions of the northern and northwestern Pacific. Tsunamis generated in that area produce the greatest waves on the northern side of the islands. About one-fourth of the historic tsunamis affecting Hawaii were generated along the western coast of South America. Tsunamis generated in the island areas of the Philippines, Indonesia, the New Hebrides, and Tonga-Kermadec have been recorded in the Hawaiian Islands, but they have not been damaging. The worst locally generated tsunamis were generated in 1869 and 1975 on the southeastern coast of the big island of Hawaii; they caused destructive waves of as much as 59 feet.

Source: Hays, W.W., ed., 1981, Facing Geologic and Hydrologic Hazards -- Earth Science Considerations: U.S. Geological Survey Professional Paper 1240B, 108 p.

Learn more:

Tsunamis in History (LiveScience)

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Tags: Seismology, Liquefaction, Earthquakes, Faults, Tectonics, Magnitude, Prediction