M2.5 Earthquake 3 km SW of Lake Shore, Washington — June 21, 2023
2023-06-21 21:01:18 UTC (2023-06-21) · approx. 1:01 PM UTC-8 local
Felt by 26 people across nearby locations.
On June 21, 2023 at 21:01 UTC, a magnitude 2.5 shallow crustal earthquake struck 3 km SW of Lake Shore, Washington, at a depth of 19.5 km and coordinates 45.6732°, -122.7248°. This earthquake was detected by 73 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 101, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 2.5 releases seismic energy equivalent to roughly 76.5 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 31 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 26 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
-122.7248°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 2.5 earthquake near Lake Shore, Washington?
The magnitude 2.5 earthquake that struck 3 km SW of Lake Shore, Washington on June 21, 2023 at 21:01 UTC had a depth of 19.5 km. For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 45.6732°, -122.7248°, which is 3 km SW of Lake Shore, Washington. View all earthquakes in Washington.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 2.5 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 2.5 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: uw61934921). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, June 21, 2023). M2.5 Earthquake 3 km SW of Lake Shore, Washington — June 21, 2023. Retrieved February 20, 2025 from https://www.earthquaketracker.org/earthquakes/event/uw61934921/