M5.3 Earthquake in the South Georgia Island region — September 16, 2021
2021-09-16 01:20:39 UTC (2021-09-16) · approx. 11:20 PM UTC-2 local
On September 16, 2021 at 01:20 UTC, a magnitude 5.3 shallow crustal earthquake struck in the South Georgia Island region, at a depth of 10.0 km and coordinates -56.4791°, -36.4742°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected.
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.
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Earthquake Details
-36.4742°E
Technical Information
Common Questions
How strong was the magnitude 5.3 earthquake in the South Georgia Island region?
The magnitude 5.3 earthquake that struck in the South Georgia Island region on September 16, 2021 at 01:20 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -56.4791°, -36.4742°, which is in the South Georgia Island region.
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.
Authoritative source: USGS event page (event ID: us7000fbn4). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 16, 2021). M5.3 Earthquake in the South Georgia Island region — September 16, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000fbn4/