4.5

M4.5 Earthquake in the South Sandwich Islands regionOctober 12, 2021

2021-10-12 17:32:23 UTC (2021-10-12) · approx. 3:32 PM UTC-2 local

MagnitudeM4.5(mb)
Time17:32 UTC3:32 PM UTC-2
Depth73.3 kmintermediate depth
Coordinates-59.709°, -26.683°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 12, 2021 at 17:32 UTC, a magnitude 4.5 intermediate depth earthquake struck in the South Sandwich Islands region, at a depth of 73.3 km and coordinates -59.7092°, -26.6834°.

Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 m — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in South Sandwich Islands, a region characterized by the South Sandwich Trench, one of Earth's most remote subduction zones.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at -59.71°, -26.68°

Earthquake Details

Magnitude
4.5 mb
Depth
73.3 km
intermediate depth
Location
-59.7092°N
-26.6834°E

Technical Information

Event ID
us6000fuxu
Event Type
earthquake
Status
✓ Reviewed
Significance
312
Azimuthal Gap
101.0°
Min Station Distance
7.626°
RMS Residual
0.71 sec
Last Updated
2021-12-18 19:58:59 UTC

Common Questions

How strong was the magnitude 4.5 earthquake in the South Sandwich Islands region?

The magnitude 4.5 earthquake that struck in the South Sandwich Islands region on October 12, 2021 at 17:32 UTC had a depth of 73.3 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -59.7092°, -26.6834°, which is in the South Sandwich Islands region.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.

Authoritative source: USGS event page (event ID: us6000fuxu). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 12, 2021). M4.5 Earthquake in the South Sandwich Islands regionOctober 12, 2021. Retrieved December 18, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000fuxu/