M3.7 Earthquake 240 km WSW of Adak, Alaska — September 23, 2020
2020-09-23 19:58:22 UTC (2020-09-23) · approx. 7:58 AM UTC+12 local
On September 23, 2020 at 19:58 UTC, a magnitude 3.7 shallow crustal earthquake struck 240 km WSW of Adak, Alaska, at a depth of 19.1 km and coordinates 51.4676°, 179.9507°.
Physical scale: An earthquake of magnitude 3.7 releases seismic energy equivalent to roughly 5.4 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 215 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
179.9507°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.7 earthquake near Adak, Alaska?
The magnitude 3.7 earthquake that struck 240 km WSW of Adak, Alaska on September 23, 2020 at 19:58 UTC had a depth of 19.1 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 3.7 earthquakes can continue for several days and gradually diminish over time.
Actions
Understanding This Data
Magnitude 3.7 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000c4i5). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, September 23, 2020). M3.7 Earthquake 240 km WSW of Adak, Alaska — September 23, 2020. Retrieved December 5, 2020 from https://www.earthquaketracker.org/earthquakes/event/us6000c4i5/