4.9

M4.9 Earthquake in the South Sandwich Islands regionDecember 26, 2023

2023-12-26 19:01:58 UTC (2023-12-26) · approx. 5:01 PM UTC-2 local

MagnitudeM4.9(mb)
Time19:01 UTC5:01 PM UTC-2
Depth39.2 kmshallow crustal
Coordinates-55.291°, -29.271°
Felt byNo felt reports
Status✓ Reviewed by USGS

On December 26, 2023 at 19:01 UTC, a magnitude 4.9 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 39.2 km and coordinates -55.2913°, -29.2708°. This earthquake was detected by 52 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

Map showing earthquake epicenter at -55.29°, -29.27°

Earthquake Details

Magnitude
4.9 mb
Depth
39.2 km
shallow crustal
Location
-55.2913°N
-29.2708°E

Technical Information

Event ID
us6000m20a
Event Type
earthquake
Status
✓ Reviewed
Significance
369
Stations Used
52
Azimuthal Gap
86.0°
Min Station Distance
4.298°
RMS Residual
0.58 sec
Last Updated
2024-03-02 21:39:36 UTC

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 December 26, 2023 at 19:01 UTC had a depth of 39.2 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -55.2913°, -29.2708°, 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.

Authoritative source: USGS event page (event ID: us6000m20a). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, December 26, 2023). M4.9 Earthquake in the South Sandwich Islands regionDecember 26, 2023. Retrieved March 2, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000m20a/