What is the difference between a tsunami and a tidal wave?
Although both are sea waves, a tsunami and a tidal wave are two different and unrelated phenomena. A tidal wave is a shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth. ("Tidal wave" was used in earlier times to describe what we now call a tsunami.) A tsunamis is an ocean wave triggered by large earthquakes that occur near or under the ocean, volcanic eruptions, submarine landslides, or by onshore landslides in which large volumes of debris fall into the water.
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Most of the world’s earthquakes, tsunamis, landslides, and volcanic eruptions are caused by the continuous motions of the many tectonic plates that make up the Earth’s outer shell. The most powerful of these natural hazards occur in subduction zones, where two plates collide and one is thrust beneath another. The U.S. Geological Survey’s (USGS) “...
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Community exposure to tsunami hazards in Hawai‘i
Hawai‘i has experienced numerous destructive tsunamis and the potential for future inundation has been described over the years using various historical events and scenarios. To support tsunami preparedness and risk-reduction planning in Hawai‘i, this study documents the variations among 91 coastal communities and 4 counties in the...
Jones, Jamie L.; Jamieson, Matthew R.; Wood, Nathan J.
The 1964 Great Alaska Earthquake and tsunamis: a modern perspective and enduring legacies
The magnitude 9.2 Great Alaska Earthquake that struck south-central Alaska at 5:36 p.m. on Friday, March 27, 1964, is the largest recorded earthquake in U.S. history and the second-largest earthquake recorded with modern instruments. The earthquake was felt throughout most of mainland Alaska, as far west as Dutch Harbor in the Aleutian Islands...
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Tsunami Hazards - A National Threat
In December 2004, when a tsunami killed more than 200,000 people in 11 countries around the Indian Ocean, the United States was reminded of its own tsunami risks. In fact, devastating tsunamis have struck North America before and are sure to strike again. Especially vulnerable are the five Pacific States--Hawaii, Alaska, Washington, Oregon, and...
50-Year-Old Mystery Solved: Seafloor Mapping Reveals Cause of 1964 Tsunami that Destroyed Alaskan Village
Minutes after the 1964 magnitude-9.2 Great Alaska Earthquake began shaking, a series of tsunami waves swept through the village of Chenega in Prince William Sound, destroying all but two of the buildings and killing 23 of the 75 inhabitants.
Are American Cities Prepared For Massive Tsunamis?
Are American Cities Prepared For Massive Tsunamis?
Geologic Evidence of Past Tsunamis in California
An extensive sedimentary deposit formed by a tsunami in 1946 was recently discovered at Pillar Point Marsh near Half Moon Bay, California. While there were photos and eyewitness accounts of the tsunami and resulting damage at the time, finding the tangible evidence in the geologic record is an important part of assessing the long-term hazard of tsunamis on California coastal communities.
California Tsunami Would Have Costly Aftermath
The fearsome aftermath of a tsunami striking California might cost at least $3.4 billion to repair, but neither of the state's nuclear power plants would be damaged, suggests a new analysis that could help officials and the public prepare for a tsunami and reduce risks before any such disasters happen.
New Findings about Indian Ocean Tsunamis Offer Lessons for Pacific Northwest
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Preparing for Tsunami Hazards on Washington’s Pacific Coast
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Animation of Tsunami Scenario in the Pacific Northwest
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A presentation on "Unusual Sources of Tsunamis From Krakatoa to Monterey Bay" by Eric Geist, USGS Research Geophysicist
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Location: Laysan Islands (Northwestern Hawaiian Islands).
PubTalk 12/2014 — Ten Years After the 2004 Indian Ocean Tsunami
How geology is reducing tsunami risk
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- Improvements in tsunamis warnings since the 2004 Indian Ocean devastation.
- Is California vulnerable to tsunamis?
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Tsunamis: Tides have nothing to do with it
Tsunamis are devastating. Usually associated with earthquakes in the Pacific, these giant surges of oceanic water can kill thousands and do billions of dollars of damage in minutes. Surprisingly, most people in Oregon are not aware of the tsunami history and hazard along our very own coast. Listen in as we examine the science of tsunamis and sit down for a special
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Nehalem town with tsunami evacuation sign
Tsunami evacuation sign in the town of Nehalem. OR.
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Extensive damage to buildings and roads, and large boats washed far ashore, provide valuable information to tsunami researchers. Here, in Natori, Japan, south of Sendai, the height of damage indicates that the water flow from the tsunami wave was about 10 meters (33 feet).