3.2

M3.2 Earthquake 238 km S of Sand Point, AlaskaSeptember 17, 2021

2021-09-17 23:15:26 UTC (2021-09-17) · approx. 12:15 PM UTC-11 local

MagnitudeM3.2(ml)
Time23:15 UTC12:15 PM UTC-11
Depth10.0 kmshallow crustal
Coordinates53.200°, -160.164°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 17, 2021 at 23:15 UTC, a magnitude 3.2 shallow crustal earthquake struck 238 km S of Sand Point, Alaska, at a depth of 10.0 km and coordinates 53.2004°, -160.1636°.

Physical scale: An earthquake of magnitude 3.2 releases seismic energy equivalent to roughly 951 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 97 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 53.20°, -160.16°

Earthquake Details

Magnitude
3.2 ml
Depth
10.0 km
shallow crustal
Location
53.2004°N
-160.1636°E

Technical Information

Event ID
us7000fc9y
Event Type
earthquake
Status
✓ Reviewed
Significance
158
Azimuthal Gap
234.0°
Min Station Distance
1.668°
RMS Residual
0.80 sec
Last Updated
2021-12-03 15:01:27 UTC

Common Questions

How strong was the magnitude 3.2 earthquake near Sand Point, Alaska?

The magnitude 3.2 earthquake that struck 238 km S of Sand Point, Alaska on September 17, 2021 at 23:15 UTC had a depth of 10.0 km. For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.2 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000fc9y). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, September 17, 2021). M3.2 Earthquake 238 km S of Sand Point, AlaskaSeptember 17, 2021. Retrieved December 3, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000fc9y/