M3.6 Earthquake 85 km WSW of Unalaska, Alaska — October 16, 2021
2021-10-16 22:26:37 UTC (2021-10-16) · approx. 11:26 AM UTC-11 local
On October 16, 2021 at 22:26 UTC, a magnitude 3.6 intermediate depth earthquake struck 85 km WSW of Unalaska, Alaska, at a depth of 113.4 km and coordinates 53.5596°, -167.7103°.
Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 3.8 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 184 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-167.7103°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.6 earthquake near Unalaska, Alaska?
The magnitude 3.6 earthquake that struck 85 km WSW of Unalaska, Alaska on October 16, 2021 at 22:26 UTC had a depth of 113.4 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 3.6 earthquakes can continue for several days and gradually diminish over time.
Actions
Understanding This Data
Magnitude 3.6 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000gcaf). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 16, 2021). M3.6 Earthquake 85 km WSW of Unalaska, Alaska — October 16, 2021. Retrieved December 25, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000gcaf/