M2.0 Earthquake 17 km SW of Tyonek, Alaska — December 18, 2021
2021-12-18 22:03:04 UTC (2021-12-18) · approx. 12:03 PM UTC-10 local
Felt by 15 people across nearby locations.
On December 18, 2021 at 22:03 UTC, a magnitude 2.0 intermediate depth earthquake struck 17 km SW of Tyonek, Alaska, at a depth of 83.7 km and coordinates 60.9518°, -151.3528°.
Physical scale: An earthquake of magnitude 2.0 releases seismic energy equivalent to roughly 15.1 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 14 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 15 citizen responses 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
-151.3528°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 2.0 earthquake near Tyonek, Alaska?
The magnitude 2.0 earthquake that struck 17 km SW of Tyonek, Alaska on December 18, 2021 at 22:03 UTC had a depth of 83.7 km. For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 60.9518°, -151.3528°, which is 17 km SW of Tyonek, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 2.0 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 2.0 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: ak021g6iacmx). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 18, 2021). M2.0 Earthquake 17 km SW of Tyonek, Alaska — December 18, 2021. Retrieved January 14, 2022 from https://www.earthquaketracker.org/earthquakes/event/ak021g6iacmx/