M3.0 Earthquake 149 km WNW of Nikolski, Alaska — July 7, 2020
2020-07-07 20:24:10 UTC (2020-07-07) · approx. 9:24 AM UTC-11 local
On July 7, 2020 at 20:24 UTC, a magnitude 3.0 shallow crustal earthquake struck 149 km WNW of Nikolski, Alaska, at a depth of 10.0 km and coordinates 53.2267°, -171.0418°.
Physical scale: An earthquake of magnitude 3.0 releases seismic energy equivalent to roughly 477 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 71 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 6.5 mainshock that occurred 23 days ago 177 km W of Nikolski, Alaska. Since the mainshock, the USGS has recorded 4 aftershocks in this area. Aftershock activity is expected to continue for weeks to months as stresses on surrounding faults redistribute.
Earthquake Details
-171.0418°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.0 earthquake near Nikolski, Alaska?
The magnitude 3.0 earthquake that struck 149 km WNW of Nikolski, Alaska on July 7, 2020 at 20:24 UTC had a depth of 10.0 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 3.0 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M6.5 one earlier?
No. This magnitude 3.0 earthquake is an aftershock of the larger magnitude 6.5 mainshock that occurred earlier 177 km W of Nikolski, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 3.0 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000an85). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, July 7, 2020). M3.0 Earthquake 149 km WNW of Nikolski, Alaska — July 7, 2020. Retrieved September 11, 2020 from https://www.earthquaketracker.org/earthquakes/event/us7000an85/