M4.5 Earthquake 27 km SSW of Unalaska, Alaska — July 12, 2026
2026-07-12 11:23:48 UTC (1 hour ago) · approx. 12:23 AM UTC-11 local
Felt by 11 people across nearby locations.
On July 12, 2026 at 11:23 UTC, a magnitude 4.5 intermediate depth earthquake struck 27 km SSW of Unalaska, Alaska, at a depth of 95.2 km and coordinates 53.6497°, -166.7155°. The earthquake was reported felt by 11 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.5 (light). This earthquake was detected by 87 seismic stations with good location accuracy and was assigned a USGS significance rating of 315, 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.
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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 11 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
-166.7155°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.5 earthquake near Unalaska, Alaska?
The magnitude 4.5 earthquake that struck 27 km SSW of Unalaska, Alaska on July 12, 2026 at 11:23 UTC had a depth of 95.2 km. It was felt by 11 people with maximum shaking intensity of MMI 3.5 (light). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 53.6497°, -166.7155°, which is 27 km SSW of Unalaska, 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.
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.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks.
Authoritative source: USGS event page (event ID: us7000szv2). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, July 12, 2026). M4.5 Earthquake 27 km SSW of Unalaska, Alaska — July 12, 2026. Retrieved July 12, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000szv2/