M4.0 Earthquake 173 km ESE of Attu Station, Alaska — October 23, 2023
2023-10-23 21:10:13 UTC (2023-10-23) · approx. 9:10 AM UTC+12 local
On October 23, 2023 at 21:10 UTC, a magnitude 4.0 shallow crustal earthquake struck 173 km ESE of Attu Station, Alaska, at a depth of 54.6 km and coordinates 52.0094°, 175.3452°.
Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
175.3452°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.0 earthquake near Attu Station, Alaska?
The magnitude 4.0 earthquake that struck 173 km ESE of Attu Station, Alaska on October 23, 2023 at 21:10 UTC had a depth of 54.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.0 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000l6vj). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 23, 2023). M4.0 Earthquake 173 km ESE of Attu Station, Alaska — October 23, 2023. Retrieved January 4, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000l6vj/