4.6

M4.6 Earthquake 40 km S of Sand Point, Alaska — October 26, 2020

2020-10-26 09:25:11 UTC (2020-10-26) · approx. 10:25 PM UTC-11 local

MagnitudeM4.6(mwr)
Time09:25 UTC≈ 10:25 PM UTC-11
Depth48.7 kmshallow crustal
Coordinates54.975°, -160.425°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 26, 2020 at 09:25 UTC, a magnitude 4.6 shallow crustal earthquake struck 40 km S of Sand Point, Alaska, at a depth of 48.7 km and coordinates 54.9747°, -160.4247°.

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

Map showing earthquake epicenter at 54.97°, -160.42°

Earthquake Details

Magnitude
4.6 mwr
Depth
48.7 km
shallow crustal
Location
54.9747°N
-160.4247°E

Technical Information

Event ID
us6000cd8r
Event Type
earthquake
Status
✓ Reviewed
Significance
326
Azimuthal Gap
74.0°
Min Station Distance
0.376°
RMS Residual
0.98 sec
Last Updated
2021-01-09 20:05:28 UTC

Common Questions

How strong was the magnitude 4.6 earthquake near Sand Point, Alaska?

The magnitude 4.6 earthquake that struck 40 km S of Sand Point, Alaska on October 26, 2020 at 09:25 UTC had a depth of 48.7 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 54.9747°, -160.4247°, which is 40 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 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: us6000cd8r). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, October 26, 2020). M4.6 Earthquake 40 km S of Sand Point, Alaska — October 26, 2020. Retrieved January 9, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000cd8r/