M4.7 Earthquake 117 km SSW of Attu Station, Alaska — October 8, 2022
2022-10-08 06:12:23 UTC (2022-10-08) · approx. 5:12 PM UTC+11 local
On October 8, 2022 at 06:12 UTC, a magnitude 4.7 shallow crustal earthquake struck 117 km SSW of Attu Station, Alaska, at a depth of 10.0 km and coordinates 51.9283°, 172.3477°. This earthquake was detected by 81 seismic stations with good location accuracy and was assigned a USGS significance rating of 340, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — 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
Earthquake Details
172.3477°E
Technical Information
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Common Questions
How strong was the magnitude 4.7 earthquake near Attu Station, Alaska?
The magnitude 4.7 earthquake that struck 117 km SSW of Attu Station, Alaska on October 8, 2022 at 06:12 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 51.9283°, 172.3477°, which is 117 km SSW of Attu Station, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 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 4.7 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000is1m). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2022, October 8, 2022). M4.7 Earthquake 117 km SSW of Attu Station, Alaska — October 8, 2022. Retrieved January 18, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000is1m/