M4.1 Earthquake in the South Sandwich Islands region — September 12, 2021
2021-09-12 20:28:09 UTC (2021-09-12) · approx. 6:28 PM UTC-2 local
On September 12, 2021 at 20:28 UTC, a magnitude 4.1 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 49.5 km and coordinates -55.7519°, -29.0109°.
Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-29.0109°E
Technical Information
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Common Questions
How strong was the magnitude 4.1 earthquake in the South Sandwich Islands region?
The magnitude 4.1 earthquake that struck in the South Sandwich Islands region on September 12, 2021 at 20:28 UTC had a depth of 49.5 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.1 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.1 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000fc42). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 12, 2021). M4.1 Earthquake in the South Sandwich Islands region — September 12, 2021. Retrieved November 23, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000fc42/