6.4

M6.4 Earthquake in the South Sandwich Islands region — July 26, 2020

2020-07-26 00:53:59 UTC (2020-07-26) · approx. 10:53 PM UTC-2 local

0

MagnitudeM6.4(mww)
Time00:53 UTC≈ 10:53 PM UTC-2
Depth10.0 kmshallow crustal
Coordinates-60.783°, -25.413°
Felt byNo felt reports
Status✓ Reviewed by USGS· Tsunami evaluation· green PAGER
green Alert— no significant casualties or damage expected
Tsunami Warning Issued

On July 26, 2020 at 00:53 UTC, a magnitude 6.4 shallow crustal earthquake struck in the South Sandwich Islands region, at a depth of 10.0 km and coordinates -60.7833°, -25.4130°.0 The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected.

Physical scale: An earthquake of magnitude 6.4 releases seismic energy equivalent to roughly 60 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 16 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 -60.78°, -25.41°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M6.4 earthquake near South Sandwich Islands region

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from submitted citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M6.4 earthquake near South Sandwich Islands region

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
6.4 mww
Depth
10.0 km
shallow crustal
Location
-60.7833°N
-25.4130°E
Intensity (MMI)
3.3
light
Community Intensity
0.0
CDI from reports

Technical Information

Event ID
us6000b46r
Event Type
earthquake
Status
✓ Reviewed
Significance
630
Azimuthal Gap
20.0°
Min Station Distance
8.818°
RMS Residual
0.57 sec
Last Updated
2025-12-22 18:38:52 UTC

Common Questions

How strong was the magnitude 6.4 earthquake in the South Sandwich Islands region?

The magnitude 6.4 earthquake that struck in the South Sandwich Islands region on July 26, 2020 at 00:53 UTC had a depth of 10.0 km. For context, this was a strong earthquake capable of causing significant damage.

Where did the earthquake occur?

The earthquake epicenter was located at -60.7833°, -25.4130°, which is in the South Sandwich Islands region.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.4 earthquakes can continue for weeks to months and gradually diminish over time.

Authoritative source: USGS event page (event ID: us6000b46r). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, July 26, 2020). M6.4 Earthquake in the South Sandwich Islands region — July 26, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000b46r/