M4.9 Earthquake in the South Sandwich Islands region — October 16, 2021
2021-10-16 02:35:18 UTC (2021-10-16) · approx. 12:35 AM UTC-2 local
On October 16, 2021 at 02:35 UTC, a magnitude 4.9 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 55.7 km and coordinates -59.6597°, -26.2423°.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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
Earthquake Details
-26.2423°E
Technical Information
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Common Questions
How strong was the magnitude 4.9 earthquake in the South Sandwich Islands region?
The magnitude 4.9 earthquake that struck in the South Sandwich Islands region on October 16, 2021 at 02:35 UTC had a depth of 55.7 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -59.6597°, -26.2423°, which is in the South Sandwich Islands region.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.
Actions
Authoritative source: USGS event page (event ID: us6000fw6c). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 16, 2021). M4.9 Earthquake in the South Sandwich Islands region — October 16, 2021. Retrieved December 25, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000fw6c/