4.7

M4.7 Earthquake in the South Sandwich Islands regionAugust 14, 2021

2021-08-14 22:17:04 UTC (2021-08-14) · approx. 8:17 PM UTC-2 local

MagnitudeM4.7(mb)
Time22:17 UTC8:17 PM UTC-2
Depth40.4 kmshallow crustal
Coordinates-58.222°, -25.279°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 14, 2021 at 22:17 UTC, a magnitude 4.7 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 40.4 km and coordinates -58.2218°, -25.2789°.

Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — 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 -58.22°, -25.28°

Earthquake Details

Magnitude
4.7 mb
Depth
40.4 km
shallow crustal
Location
-58.2218°N
-25.2789°E

Technical Information

Event ID
us7000f3rh
Event Type
earthquake
Status
✓ Reviewed
Significance
340
Azimuthal Gap
83.0°
Min Station Distance
7.383°
RMS Residual
0.91 sec
Last Updated
2021-10-29 14:46:49 UTC

Common Questions

How strong was the magnitude 4.7 earthquake in the South Sandwich Islands region?

The magnitude 4.7 earthquake that struck in the South Sandwich Islands region on August 14, 2021 at 22:17 UTC had a depth of 40.4 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -58.2218°, -25.2789°, which is in the South Sandwich Islands region.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 earthquakes can continue for several days and gradually diminish over time.

Authoritative source: USGS event page (event ID: us7000f3rh). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, August 14, 2021). M4.7 Earthquake in the South Sandwich Islands regionAugust 14, 2021. Retrieved October 29, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000f3rh/