Washington Earthquakes

Monitor real-time earthquake activity in Washington State, home to some of the most significant seismic hazards in the United States. This interactive map displays all earthquakes of magnitude 1.5 and above from the USGS database. Washington sits in the Cascadia Subduction Zone, capable of producing magnitude 9+ megaquakes, and contains several active crustal faults beneath major population centers.

Did you know? The Cascadia Subduction Zone last ruptured in 1700, producing a magnitude 9.0 earthquake that sent a tsunami all the way to Japan.

Understanding the Map

Each colored circle represents an earthquake location. Click any circle to see detailed information including magnitude, location, time, and depth. Use the time filter buttons to view earthquakes from the last hour, 24 hours, 7 days, or 30 days. Washington experiences frequent small earthquakes, particularly around Puget Sound and along the volcanic Cascade Range.

Live Washington Earthquake Map Showing Real-time USGS Data

Did you know?
Seattle sits atop the Seattle Fault, which last ruptured around 900 CE, lifting the shoreline by up to 20 feet and triggering a tsunami in Puget Sound.
Source: Washington Department of Natural Resources

About Washington Earthquakes

Washington State faces earthquake threats from three primary sources: the offshore Cascadia Subduction Zone capable of magnitude 9+ megaquakes, shallow crustal faults beneath Puget Sound and the Cascade Range, and deep earthquakes within the subducting Juan de Fuca plate. The state experiences frequent seismic activity, with thousands of earthquakes recorded annually, though most are too small to be felt.

Major Seismic Hazards

  • Cascadia Subduction Zone: Offshore fault capable of magnitude 9+ megaquakes and devastating tsunamis, ruptures approximately every 300-600 years
  • Seattle Fault: East-west trending fault running through downtown Seattle, last major rupture around 900 CE produced M7+ earthquake
  • South Whidbey Island Fault: Active fault zone in northern Puget Sound, capable of M7+ earthquakes
  • Tacoma Fault: Runs through Tacoma and surrounding areas, part of the Seattle Fault Zone system
  • Deep Intraslab Earthquakes: Occur 30-70 km deep within the subducting Juan de Fuca plate, including the 2001 M6.8 Nisqually earthquake
  • Mount St. Helens & Cascade Volcanoes: Frequent small earthquakes associated with volcanic activity

Seismically Active Regions

  • Puget Sound Basin: Seattle, Tacoma, Olympia – highest population exposure to earthquake hazards
  • Cascade Range: Mount Rainier, Mount St. Helens, Mount Baker – frequent volcanic earthquakes
  • Olympic Peninsula: Near the subduction zone, frequent small earthquakes
  • Columbia Basin: Eastern Washington, lower seismic activity but historical large events
  • Strait of Juan de Fuca: Offshore and nearshore seismic activity along plate boundary
Did you know? Washington experiences three types of earthquakes: shallow crustal (0-30 km deep), deep intraslab (30-70 km deep within the subducting plate), and megathrust events on the Cascadia Subduction Zone interface.
Source: USGS Earthquake Hazards Program

Historical Major Earthquakes

  • 1700 Cascadia (M9.0): Megathrust earthquake on Cascadia Subduction Zone, tsunami reached Japan
  • 1872 North Cascades (M6.8-7.4): Largest historical earthquake in Washington, felt from British Columbia to Oregon
  • 1949 Olympia (M6.8): Deep intraslab earthquake, 8 deaths, significant damage in Olympia and Tacoma
  • 1965 Seattle-Tacoma (M6.7): Deep earthquake south of Seattle, 7 deaths, $12.5 million in damage
  • 2001 Nisqually (M6.8): Deep intraslab earthquake near Olympia, 1 death, $2 billion in damage

Earthquake Preparedness

Washington has implemented the ShakeAlert earthquake early warning system, which can provide seconds to minutes of warning before strong shaking arrives. The state also participates in the annual Great Washington ShakeOut earthquake drill. Given the Cascadia megaquake threat, residents should prepare for extended disruptions to utilities, transportation, and emergency services.

Earthquake Safety Checklist

  • Keep a 2-week supply of food, water, and medications (Cascadia event could disrupt services for weeks)
  • Secure heavy furniture and water heaters
  • Know “Drop, Cover, and Hold On” procedures
  • Download the MyShake app for earthquake early warnings
  • Have an out-of-state emergency contact
  • If near coast, know tsunami evacuation routes and assembly areas
  • Participate in the Great Washington ShakeOut drill
Did you know? When a Cascadia megaquake occurs, coastal areas may have only 15-30 minutes to reach high ground before tsunami waves arrive. Scientists estimate a 10-15% probability of a magnitude 9+ Cascadia earthquake within the next 50 years.
Source: USGS – Cascadia Subduction Zone

Frequently Asked Questions

Why is Washington at risk for large earthquakes?

Washington sits above the Cascadia Subduction Zone where the Juan de Fuca plate subducts beneath North America, capable of producing magnitude 9+ megaquakes. The state also has active crustal faults beneath major cities like Seattle and Tacoma.

What was the largest earthquake in Washington?

The 1700 Cascadia earthquake, estimated at magnitude 9.0, was the largest. The largest in recorded history was the 1872 North Cascades earthquake at magnitude 6.8-7.4.

Does Washington have an earthquake early warning system?

Yes. The ShakeAlert system provides early warnings for earthquakes, giving seconds to minutes of advance notice before strong shaking begins.

🗺️ Related Maps

View broader region: United States Earthquakes

View other states: California | Alaska |

More resources: WA DNR Earthquake Information | WA Emergency Management | Pacific Northwest Seismic Network

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