M4.6 Earthquake 47 km WSW of Atka, Alaska — December 17, 2020
2020-12-17 16:32:12 UTC (2020-12-17) · approx. 4:32 AM UTC-12 local
Felt by 1 person across nearby locations.
On December 17, 2020 at 16:32 UTC, a magnitude 4.6 intermediate depth earthquake struck 47 km WSW of Atka, Alaska, at a depth of 80.6 km and coordinates 52.0067°, -174.8164°.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.
Learn more: Magnitude scale · Aftershock sequences
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-174.8164°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.6 earthquake near Atka, Alaska?
The magnitude 4.6 earthquake that struck 47 km WSW of Atka, Alaska on December 17, 2020 at 16:32 UTC had a depth of 80.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 52.0067°, -174.8164°, which is 47 km WSW of Atka, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days and gradually diminish over time.
Has Alaska had earthquakes this big before?
The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 4.6 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000crui). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, December 17, 2020). M4.6 Earthquake 47 km WSW of Atka, Alaska — December 17, 2020. Retrieved February 27, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000crui/