How do landslides cause tsunamis?
Tsunamis are large, potentially deadly and destructive sea waves, most of which are formed as a result of submarine earthquakes. They can also result from the eruption or collapse of island or coastal volcanoes and from giant landslides on marine margins. These landslides, in turn, are often triggered by earthquakes. Tsunamis can be generated on impact as a rapidly moving landslide mass enters the water or as water displaces behind and ahead of a rapidly moving underwater landslide.
Research in the Canary Islands (off the northwestern coast of Africa) concludes that there have been at least five massive volcano landslides that occurred in the past, and that similar large events might occur in the future. Giant landslides in the Canary Islands could potentially generate large tsunami waves at both close and very great distances, and could potentially devastate large areas of coastal land as far away as the eastern seaboard of North America.
Rock falls and rock avalanches in coastal inlets, such as those that have occurred in the past at Tidal Inlet in Alaska's Glacier Bay National Park, have the potential to cause regional tsunamis that pose a hazard to coastal ecosystems and human settlements. On July 9, 1958, a magnitude 7.9 earthquake on the Fairweather Fault triggered a rock avalanche at the head of Lituya Bay, Alaska. The landslide generated a wave that ran up 524 meters (1,719 feet) on the opposite shore and sent a 30-meter-high wave through Lituya Bay, sinking two fishing boats and killing two people.
Learn more: Tsunamis and Tsunami Hazards
Related Content
Can major landslides and debris flows happen in all areas of the U.S.?
Why study landslides?
What is a landslide and what causes one?
What is the difference between a tsunami and a tidal wave?
Is there a system to warn populations of an imminent occurrence of a tsunami?
What are Tsunamis?
Could a large tsunami happen in the United States?
New Landslide Guidebook for Puerto Rico Residents
A new landslide guidebook released February 5 is now available for Puerto Rico residents to learn more about the landslide hazards that can impact the island.
Landslide Risks Highlighted in New Online Tool
The U.S. Geological Survey today unveiled a new web-based interactive map that marks an important step toward mapping areas that could be at higher risk for future landslides. In collaboration with state geological surveys and other federal agencies, USGS has compiled much of the existing landslide data into a searchable, web-based interactive map called the U.S. Landslide Inventory Map.
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.
Earthquake/Tsunami Hazard in Caribbean Higher Than Previously Thought
Enough strain may be currently stored in an earthquake zone near the island of Guadeloupe to cause a magnitude 8 or larger earthquake and subsequent tsunami in the Caribbean, according to a new U.S. Geological Survey study.
USGS Scientist to Present Evidence for Cause of Caribbean Tsunamis a Boston Meeting
The Caribbean is not renowned for its potential to generate the huge waves known as "tsunamis" that often occur in the Pacific. And scientists worldwide refer to them by their Japanese name "tsunami", which means "harbor wave." Yet these long-period waves are not confined to the Pacific Ocean.
Documenting landslides in Puerto Rico caused by Hurricane Maria.
Bill Schulz, USGS Research Geologist, takes photographs of Puerto Rican hillsides from a U.S. Army helicopter to document landslides caused by Hurricane Maria. This work will help identify areas around Puerto Rico with the highest risk of more landslides, which is information the Federal Emergency Management Agency will use to determine the best way to mitigate and prepare
...Big Sur landslide on May 20, 2017
USGS air photo of the Mud Creek landslide, taken on May 27, 2017.
PubTalk 1/2017 — Unusual sources of tsunamis
A presentation on "Unusual Sources of Tsunamis From Krakatoa to Monterey Bay" by Eric Geist, USGS Research Geophysicist
- Not all tsunamis are generated by earthquakes.
- Tsunamis can be caused by volcanoes, landslides, and even atmospheric disturbances
- Data from tide gauges can help unravel the complex physics of these sources
Videographers:
New Zealand Landslides
Photograph showing landslides covering State Route 1 near Ohau Point. The route was impacted my several landslides and is the main north-south highway on the eastern part of the South Island of New Zealand.
As many as 80,000 landslides occurred as the result of a magnitude 7.8 earthquake in New Zealand in November of 2016. The earthquake and landslides caused
...Landsat View of Landslide in Glacier Bay
On August 7, the Operational Land Imager sensor aboard Landsat 8 captured the black stain of the landslide. Credit: USGS/NASA Landsat Program.
2014 Landslide in Washington State
Photograph from an aerial survey showing the extent and impacts from the landslide in northwest Washington that occurred on March 22, 2014. The survey was conducted by the Washington State Department of Transportation, Washington State Department of Natural Resources, USGS, and King County Sheriff's Office.
USGS CoreCast: Landslide Hazards
Landslides occur in all 50 states and U.S. territories, and cause $1-2 billion in damages and more than 25 fatalities on average each year. USGS scientists aim to improve our understanding of landslide hazards to help protect communities and reduce associated losses.
Video Sections:
- Types of Landslides
- USGS Science
Volcano Web Shorts 2: Debris Flows
Debris flows are hazardous flows of rock, sediment and water that surge down mountain slopes and into adjacent valleys. Hydrologist Richard Iverson describes the nature of debris-flow research and explains how debris flow experiments are conducted at the USGS Debris Flow Flume, west of Eugene, Oregon. Spectacular debris flow footage, recorded by Franck Lavigne of the
2005 Landslide in La Conchita, CA
On January 10, 2005, a landslide struck the community of La Conchita in Ventura County, California, destroying or seriously damaging 36 houses and killing 10 people. For a USGS rerpot on this event, please see USGS Open-file report, "Landslide Hazards at La Conchita, California."
landslide graphic
graphic illustration of the parts of a landslide
Mill Creek landslide
Photo 1: Aerial view of the Mill Creek landslide blocking Highway 50.