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Tsunamis are destructive waves caused by sudden displacement of ocean water. Tsunamis most often appear on shore as a rapidly receding tide or rapidly rising flood. In the United States, the Pacific coastal states – Oregon, Washington, California, Alaska, and Hawaii – are at greatest risk for destructive tsunamis.


Inundation at Pago Pago, American Samoa, from the 2009 Samoa tsunami. Image Credit: NOAA/NGDC

A tsunami is a series of waves formed in a body of water by the sudden displacement of the entire water column. Most large tsunamis are caused by undersea earthquakes, though landslides, volcanic eruptions, explosions, and even meteorite impacts can also cause them. Tsunamis commonly appear on shore as a rapidly receding tide or rapidly rising flood. Tsunamis sometimes provide natural warning signs to people living on coasts, especially close to the tsunami-causing event, such as a rapidly receding tide prior to the waves' arrival. Global monitoring systems also provide critical early warning to coastal populations.[1]   Read more

Frequently Asked Questions

American Geosciences Institute
National Oceanic and Atmospheric Administration

Latest News

Cracked road from earthquake
January 30, 2018 On January 30, the Senate Committee on Energy and Natural Resources held a full committee hearing to address the role of the U.S. Geological Survey (USGS), U.S. Forest Service (USFS), and National Oceanic and Atmospheric Administration (NOAA) in preparing for and responding to...
April 6, 2017 The Hazards Caucus Alliance, a network that supports the Congressional Hazards Caucus, hosted a briefing on April 6 about how geologic and hazards mapping and monitoring are used to prepare and protect communities from natural hazards. The Hazards Caucus provides congressional staff...
Cracked road from earthquake
March 27, 2017 The Pacific Northwest Earthquake Preparedness Act (H.R.654) moved a step closer to becoming law when the bill passed the House on March 27. Representative Pete DeFazio (D-OR-4) introduced H.R.654 on January 24. The bill would establish an earthquake and tsunami inter-agency task...
IES Oceans Glyph
January 10, 2017 Rep. Suzanne Bonamici (D-OR-1) introduced the Tsunami Warning, Education, and Research Act (H.R. 312) on January 10. This bill directs the National Oceanic and Atmospheric Administration (NOAA) to strengthen tsunami research, detection, forecasting, warning, and mitigation programs...
Cracked road from earthquake
November 10, 2016 On November 10, the National Academy of Sciences (NAS) hosted a panel discussion on the Cascadia Subduction Zone (CSZ) and its potential for large scale fault rupture. Research from a number of academic institutions has suggested that such a rupture is capable of producing a...
Screenshot of a graphic showing the Cascadia Subduction Zone
On Thursday November 10, The National Academies' Board on Earth Science and Resources and the Committee on Seismology and Geodynamics held a joint meeting on The Cascadia Subduction Zone: Science, Impacts, and Response. The meeting provided a forum for the discussion of progress and future...
#MapOfTheDay! Check out this interactive map of estimated tsunami travel times: bit.ly/1QTKEY9 #TsunamiDay2016 @NOAA
#MapOfTheDay! Tomorrow is World Tsunami Awareness Day, so today the Critical Issues Program (@AGI_GeoIssues) shared an interactive map of estimated tsunami travel times to coastal locations from the National Oceanic and Atmospheric Administration (@NOAA), which you can find at http://bit.ly/1QTKEY9...
IES Oceans Glyph
February 26, 2015                                                              The Senate Commerce, Science, and Transportation Committee marked up and passed the Tsunami Warning, Education, and Research Act of 2015 (H.R.34) on February 26. The legislation reauthorizes programs that support tsunami...
NASA hurricane satellite image
January 7, 2015 On January 7, the House passed two bills that focus on research and preparedness for tsunami and windstorm hazards. The Tsunami Warning, Education, and Research Act (H.R.34) introduced by Rep. Suzanne Bonamici (D-OR) reauthorizes programs that support tsunami forecasting and coastal...
Atlantic waves
September 8, 2014 On September 8, the House of Representatives passed the Tsunami Warning, Education, and Research Act (H.R. 5309) by voice vote. Introduced by Representatives Susan Bonimici (D-OR) and Dana Rohrbacher (R-CA), H.R. 5309 would reauthorize the National Tsunami Hazard Mitigation...

GOLI Online Courses

GOLI Course: Communicating Cascadia's Earthquake Risk. Image Credit: FEMA / Photo by Mustafa Lazkani
Course Type: GOLI Online Course

Geoscience research is at the forefront of characterizing the earthquake risks associated with the Cascadia subduction zone in the Pacific Northwest. This course covers the science and its implications for policy decisions and resiliency efforts.

Geological Surveys Database Publications

2003, Oregon Department of Geology and Mineral Industries

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2005, Oregon Department of Geology and Mineral Industries

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2001, United States Geological Survey
Many earthquakes and tsunamis have occurred in the northeastern Caribbean, where the movements of the Earth's surface plates are rapid and complicated. Future such events pose serious hazards to the 3.7 million people who live in Puerto Rico and the U.S. Virgin Islands.
2013, United States Geological Survey
On March 11, 2011, the Tohoku earthquake and the resulting tsunami devastated Japan with a disaster of unfathomable proportions. Five thousand miles away, the waves from Tohoku caused
2003, Oregon Department of Geology and Mineral Industries

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2005, Washington Geological Survey

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1998, Washington Geological Survey

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2000, United States Geological Survey
In 1946, 1960, and 1964, major tsunamis (giant sea waves usually caused by earthquakes or submarine landslides) struck coastal areas of the Pacific Ocean. In the U.S. alone, these tsunamis killed hundreds of people and caused many tens of millions of dollars in damage. Recent events in Papua New...
2001, United States Geological Survey
What is the Advanced National Seismic System? The Advanced National Seismic System (ANSS) is designed to organize, modernize, and standardize operations of seismic networks in the United States to improve the NationâEuro TMs ability to respond effectively to damaging earthquakes, volcanoes, and...
2011, United States Geological Survey
The State of Hawaii has a history of damaging earthquakes. Earthquakes in the State are primarily the result of active volcanism and related geologic processes. It is not a question of "if" a devastating quake will strike HawaiâEuro ~i but rather "when." Tsunamis generated by...