Skip to main content
U.S. flag

An official website of the United States government

USGS-NOAA cruise maps Cascadia subduction zone to assess earthquake hazards

From July 31 to August 23, a joint USGS-NOAA cruise mapped seafloor depths, texture, and gas seeps in the Cascadia subduction zone offshore of Washington, Oregon, and northern California.

A woman stands on the desk of a ship as it sails under a bridge, she is smiling and holding on to the railing.
USGS geophysicist Janet Watt on board NOAA ship Rainier as it sets sail from Newport Marina in Yaquina Bay, Oregon. Yaquina Bay Bridge is overhead.

From July 31 to August 23, a joint USGS-NOAA cruise mapped seafloor depths, texture, and gas seeps in the Cascadia subduction zone offshore of Washington, Oregon, and northern California. The largest earthquakes in the world occur within subduction zones along the giant fault between the down-going and overriding plates. Such earthquakes have potential to trigger large tsunamis by raising or lowering parts of the seafloor. During the cruise, scientists mapped a total of 6,452 square kilometers of seafloor. They identified new faults offsetting the seabed, possible mud volcanoes, and numerous seeps that highlight the region’s geologic activity. Results from this mapping and related efforts will provide key baseline information for assessing earthquake, tsunami, and landslide hazards and developing situational-awareness products, as part of USGS work on Reducing Risk where Tectonic Plates Collide.

 

View from the top deck of a ship on water, looking down on the bow with three people standing, with a bridge in the background.
Entering Yaquina Bay, Oregon aboard the NOAA ship Rainier, approaching the Yaquina Bay Bridge with Newport Marina off to the right in the distance.
A man controlling a computer mouse is sitting at a computer looking at a computer monitor.
USGS scientist Pete Dartnell processes multibeam data collected from off the Pacific Northwest coast on a research cruise aboard NOAA ship Rainier.

 

Get Our News

These items are in the RSS feed format (Really Simple Syndication) based on categories such as topics, locations, and more. You can install and RSS reader browser extension, software, or use a third-party service to receive immediate news updates depending on the feed that you have added. If you click the feed links below, they may look strange because they are simply XML code. An RSS reader can easily read this code and push out a notification to you when something new is posted to our site.