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.

Related Content

Filter Total Items: 5

What is it about an earthquake that causes a tsunami?

Although earthquake magnitude is one factor that affects tsunami generation, there are other important factors to consider. The earthquake must be a shallow marine event that displaces the seafloor. Thrust earthquakes (as opposed to strike slip) are far more likely to generate tsunamis, but small tsunamis have occurred in a

...Read Full Answer

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

...Read Full Answer

Is there a system to warn populations of an imminent occurrence of a tsunami?

NOAA maintains the U.S. Tsunami Warning Centers, which work in conjunction with USGS seismic networks to help determine when and where to issue tsunami warnings. If an earthquake meets certain criteria for potentially generating a tsunami, the pop-up window and the event page for that

...Read Full Answer

What are Tsunamis?

Tsunamis are ocean waves triggered by large earthquakes that occur near or under the ocean, volcanic eruptions, submarine landslides, and by onshore landslides in which large volumes of debris fall into the water. Scientists do not use the term "tidal wave" because these waves are not caused by tides. Tsunami waves are

...Read Full Answer

Could a large tsunami happen in the United States?

Large tsunamis have occurred in the United States and will undoubtedly occur again.

Significant earthquakes around the Pacific rim have generated tsunamis that struck Hawaii, Alaska, and the U.S. west coast. One of the largest and most devastating tsunamis that Hawaii has experienced was in 1946 from an earthquake

...Read Full Answer
Filter Total Items: 6
Date published: February 1, 2016

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. 

Date published: September 18, 2015

Are American Cities Prepared For Massive Tsunamis?

Are American Cities Prepared For Massive Tsunamis?

Date published: May 20, 2014

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.

Date published: September 5, 2013

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.

Date published: October 29, 2008

New Findings about Indian Ocean Tsunamis Offer Lessons for Pacific Northwest

The Indian Ocean tsunami that claimed a quarter million lives was not the first nor last of its kind, according to reports in the October 30 issue of the scientific journal Nature.

Date published: May 4, 2005

Science Used to Assess Earthquakes and Tsunamis Can Help Keep America Safe

Reston, VA – Learn how scientific assessment of earthquakes and tsunamis can reduce risk and the loss of life and property when natural hazards strike.

Filter Total Items: 8
Preparing for Tsunami Hazards on Washington’s Pacific Coast
February 1, 2017

Preparing for Tsunami Hazards on Washington’s Pacific Coast

Animation of Tsunami Scenario in the Pacific Northwest
February 1, 2017

Animation of what a potential tsunami would look like generated from a large and hypothetical magnitude 9 subduction earthquake in the U.S. Pacific Northwest. The height of the tsunami waves is exaggerated compared to the land surface. Credit: Eric Geist, USGS

Large waves crashing on rocks at beach.
2016 (approx.)

Large storm waves crashing on the rocks near Santa Cruz, California

Southeast Asia - Tsunami brought in distructive waves and destruction.
November 28, 2016

Southeast Asia in May 2013. Tsunami brought in dangerous waves and destruction. 

Image: Large Breaking Wave on Beach
March 15, 2016

Photograph showing the impact of a large wave at the south shore of Laysan Island, with endangered Laysan teal in the foreground.

Location: Laysan Islands (Northwestern Hawaiian Islands).

USGS
October 26, 2009

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 interview with USGS scientist Brian Atwater and Oregon Office of Emergency Management Geologic Hazard Coordinator Althea Turner. Plus, a recap of this week's Geological Society of America annual meeting.

Wrecked buildings and washed-up boat far from water after the 2011 earthquake and tsunami in Japan in 2011.

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).

Nehalem town with tsunami evacuation sign

Tsunami evacuation sign in the town of Nehalem. OR.