Earthquakes and Faults

Societal Issue: Uncertainty related to rupture extent, slip distribution, and recurrence of past subduction megathrust earthquakes in the Pacific Northwest (northern CA, OR, WA, and southern BC) leads to ambiguity in earthquake and tsunami hazard assessments and hinders our ability to prepare for future events.

Learn about the USGS Pacific Coastal and Marine Science Center Marine Facility’s vast array of field equipment, sampling devices, and mapping systems, and our capabilities. Our engineers, designers, mechanics, and technicians have also designed and developed some of the specialized field equipment we use in field operations in the nearshore, in the deep sea, and on land.

The Pacific Coastal and Marine Science Center geotechnical group investigates the causes of ground deformation and ground failure as a result of earthquakes, storms, and wave action

The nation's coastlines are vulnerable to the interrelated hazards posed by earthquakes, landslides, and tsunamis. In the marine environment these events often occur in concert, and distant triggers can cause severe local effects, making the issue global in scope. As the population continues to migrate toward the coastlines, the social impacts of these hazards are expected to grow.

Marine geohazards are sudden and extreme events beneath the ocean that threaten coastal populations. Such underwater hazards include earthquakes, volcanic eruptions, landslides, and tsunamis.

The GeoEel is a multichannel digital streamer system, with hydrophones in a long, green hose. The streamer is towed like a long snake in the water from a vessel, and the hydrophones "listen" for and record the signals from the seismic sound source.

Seismic source for marine reflection surveys

The Geospace Navigator bird is a streamer depth control device, used with a high-resolution seismic system to regulate and record the depth of the streamer.

Description of the high-resolution multichannel seismic system at the Marine Facility (MarFac) of the USGS Pacific Coastal and Marine Science Center, for seafloor mapping

Over the last 100 years, the Queen Charlotte-Fairweather fault system has produced large-magnitude earthquakes affecting both Canada and the U.S. To fill in missing details about its offshore location and structure, USGS uses sophisticated techniques to truly understand the fault’s hazard potential.

Here you will find general information on the science behind tsunami generation, computer animations of tsunamis, and summaries of past field studies.

Shortly after the Great San Francisco earthquake of April 18, 1906, a sea level disturbance (tsunami) was recorded at the Presidio tide gauge station in San Francisco (the station is now located nearby at Ft. Point). What type of mechanism (earthquake rupture, landslide, other) generated the tsunami recorded at the Presidio tide gauge station?