M4.5 Earthquake 59 km SSE of Adak, Alaska — June 11, 2025
2025-06-11 20:36:17 UTC (2025-06-11) · approx. 8:36 AM UTC-12 local
Aftershock of the M5.0 mainshock.
On June 11, 2025 at 20:36 UTC, a magnitude 4.5 shallow crustal earthquake struck 59 km SSE of Adak, Alaska, at a depth of 37.0 km and coordinates 51.3695°, -176.3359°. This earthquake was detected by 104 seismic stations with good location accuracy and was assigned a USGS significance rating of 312, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.0 mainshock that occurred 2 days ago 94 km SSE of Adak, Alaska. Since the mainshock, the USGS has recorded 4 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.
Learn more: Magnitude scale · Aftershock sequences
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Earthquake Details
-176.3359°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.5 earthquake near Adak, Alaska?
The magnitude 4.5 earthquake that struck 59 km SSE of Adak, Alaska on June 11, 2025 at 20:36 UTC had a depth of 37.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 51.3695°, -176.3359°, which is 59 km SSE of Adak, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.0 one earlier?
No. This magnitude 4.5 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 94 km SSE of Adak, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Alaska had earthquakes this big before?
The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 4.5 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000qjn2). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, June 11, 2025). M4.5 Earthquake 59 km SSE of Adak, Alaska — June 11, 2025. Retrieved August 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000qjn2/