M6.4 Earthquake 46 km ESE of Nikolski, Alaska — December 1, 2020
2020-12-01 16:22:39 UTC (2020-12-01) · approx. 5:22 AM UTC-11 local
Felt by 11 people across nearby locations. Maximum shaking intensity MMI 7.3 (severe).
On December 1, 2020 at 16:22 UTC, a magnitude 6.4 shallow crustal earthquake struck 46 km ESE of Nikolski, Alaska, at a depth of 23.0 km and coordinates 52.7551°, -168.2401°. The earthquake was reported felt by 11 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 7.3 (severe). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Akutan (population 1,027).
Physical scale: An earthquake of magnitude 6.4 releases seismic energy equivalent to roughly 60 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 16 km — 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
Nearest Populated Places
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 11 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
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 5,486 |
Earthquake Details
-168.2401°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 6.4 earthquake near Nikolski, Alaska?
The magnitude 6.4 earthquake that struck 46 km ESE of Nikolski, Alaska on December 1, 2020 at 16:22 UTC had a depth of 23.0 km. It was felt by 11 people with maximum shaking intensity of MMI 7.3 (severe). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at 52.7551°, -168.2401°, which is 46 km ESE of Nikolski, Alaska. The nearest populated place is Akutan (population 1,027). View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.4 earthquakes can continue for weeks to months 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 6.4 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000clnv). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, December 1, 2020). M6.4 Earthquake 46 km ESE of Nikolski, Alaska — December 1, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000clnv/