M2.4 Earthquake 2 km N of City of Sammamish, Washington — April 18, 2025
2025-04-18 23:56:02 UTC (2025-04-18) · approx. 3:56 PM UTC-8 local
Felt by 10 people across nearby locations.
On April 18, 2025 at 23:56 UTC, a magnitude 2.4 shallow crustal earthquake struck 2 km N of City of Sammamish, Washington, at a depth of 20.4 km and coordinates 47.6295°, -122.0325°. This earthquake was detected by 68 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 95, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 2.4 releases seismic energy equivalent to roughly 66.6 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 29 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Washington, a region characterized by the Cascadia Subduction Zone, where the Juan de Fuca Plate subducts beneath North America and is capable of producing M9+ megathrust earthquakes. The nearest mapped fault system is the Cascadia Subduction Zone. View all earthquakes in Washington.
Learn more: Cascadia Subduction Zone · Magnitude scale · Aftershock sequences
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 10 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-122.0325°E
Technical Information
Common Questions
How strong was the magnitude 2.4 earthquake near City of Sammamish, Washington?
The magnitude 2.4 earthquake that struck 2 km N of City of Sammamish, Washington on April 18, 2025 at 23:56 UTC had a depth of 20.4 km. For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 47.6295°, -122.0325°, which is 2 km N of City of Sammamish, Washington. View all earthquakes in Washington.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 2.4 earthquakes can continue for several days and gradually diminish over time.
Has Washington had earthquakes this big before?
The largest recorded earthquake in Washington was the M7.4 offshore earthquake of April 13, 1949. Today's magnitude 2.4 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: uw62094381). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, April 18, 2025). M2.4 Earthquake 2 km N of City of Sammamish, Washington — April 18, 2025. Retrieved June 27, 2025 from https://www.earthquaketracker.org/earthquakes/event/uw62094381/