M4.5 Earthquake in the South Sandwich Islands region — December 17, 2021
2021-12-17 17:43:41 UTC (2021-12-17) · approx. 3:43 PM UTC-2 local
On December 17, 2021 at 17:43 UTC, a magnitude 4.5 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 49.8 km and coordinates -59.8292°, -26.3160°.
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
Earthquake Details
-26.3160°E
Technical Information
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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 December 17, 2021 at 17:43 UTC had a depth of 49.8 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -59.8292°, -26.3160°, 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.
Actions
Authoritative source: USGS event page (event ID: us6000geii). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 17, 2021). M4.5 Earthquake in the South Sandwich Islands region — December 17, 2021. Retrieved March 1, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000geii/