M4.9 Earthquake in the South Sandwich Islands region — October 15, 2023
2023-10-15 03:20:01 UTC (2023-10-15) · approx. 1:20 AM UTC-2 local
On October 15, 2023 at 03:20 UTC, a magnitude 4.9 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 10.0 km and coordinates -58.4584°, -23.1887°. This earthquake was detected by 33 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.
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
-23.1887°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 15, 2023 at 03:20 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -58.4584°, -23.1887°, 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: us6000lfn8). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 15, 2023). M4.9 Earthquake in the South Sandwich Islands region — October 15, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lfn8/