5.3

M5.3 Earthquake 203 km S of Sand Point, Alaska — December 16, 2020

2020-12-16 05:49:23 UTC (2020-12-16) · approx. 6:49 PM UTC-11 local

MagnitudeM5.3(mww)
Time05:49 UTC≈ 6:49 PM UTC-11
Depth10.5 kmshallow crustal
Coordinates53.523°, -160.064°
Felt byNo felt reports
Status✓ Reviewed by USGS· Tsunami evaluation
Tsunami Warning Issued

On December 16, 2020 at 05:49 UTC, a magnitude 5.3 shallow crustal earthquake struck 203 km S of Sand Point, Alaska, at a depth of 10.5 km and coordinates 53.5231°, -160.0638°.

Physical scale: An earthquake of magnitude 5.3 releases seismic energy equivalent to roughly 1 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.7 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

Map showing earthquake epicenter at 53.52°, -160.06°

Earthquake Details

Magnitude
5.3 mww
Depth
10.5 km
shallow crustal
Location
53.5231°N
-160.0638°E

Technical Information

Event ID
us7000crgf
Event Type
earthquake
Status
✓ Reviewed
Significance
432
Azimuthal Gap
55.0°
Min Station Distance
1.339°
RMS Residual
0.74 sec
Last Updated
2025-12-22 17:59:34 UTC

Common Questions

How strong was the magnitude 5.3 earthquake near Sand Point, Alaska?

The magnitude 5.3 earthquake that struck 203 km S of Sand Point, Alaska on December 16, 2020 at 05:49 UTC had a depth of 10.5 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 53.5231°, -160.0638°, which is 203 km S of Sand Point, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.3 earthquakes can continue for days to weeks 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 5.3 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000crgf). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, December 16, 2020). M5.3 Earthquake 203 km S of Sand Point, Alaska — December 16, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000crgf/