M3.1 Earthquake 168 km S of False Pass, Alaska — January 19, 2023
2023-01-19 20:11:59 UTC (2023-01-19) · approx. 9:11 AM UTC-11 local
On January 19, 2023 at 20:11 UTC, a magnitude 3.1 shallow crustal earthquake struck 168 km S of False Pass, Alaska, at a depth of 35.0 km and coordinates 53.3396°, -163.4280°.
Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 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 16 days ago 143 km S of False Pass, Alaska. Since the mainshock, the USGS has recorded 29 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
-163.4280°E
Technical Information
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Common Questions
How strong was the magnitude 3.1 earthquake near False Pass, Alaska?
The magnitude 3.1 earthquake that struck 168 km S of False Pass, Alaska on January 19, 2023 at 20:11 UTC had a depth of 35.0 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.1 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 3.1 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 143 km S of False Pass, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 3.1 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000jjib). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, January 19, 2023). M3.1 Earthquake 168 km S of False Pass, Alaska — January 19, 2023. Retrieved March 31, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000jjib/