M6.3 earthquake in South Sandwich Islands region

Tuesday, October 25, 2022, 00:13:01 UTC · 58.777°S, 26.141°W

A magnitude 6.3 earthquake struck in South Sandwich Islands region on Tuesday, October 25, 2022, 00:13:01 UTC, at a depth of 79.0 km (intermediate). USGS received 3 “Did You Feel It?” reports, with a maximum reported intensity of VII (very strong). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M7.1 on August 22, 2021.

Magnitude: 6.3; Strong · mww
Depth: 79 km; Intermediate
Felt reports: 3; Max intensity VII
Est. shaking: V; Moderate (ShakeMap)
PAGER alert: Green; Impact estimate
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

43 kilotons of TNT

That is about 3 times the Hiroshima bomb. It released about 89 times the energy of a magnitude 5.0.

Tectonic setting

117 km

from the nearest mapped plate boundary, between the Sandwich and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: intermediate

79 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

Did You Feel It?

Where it was felt

3 people reported feeling this earthquake to USGS; a per-place breakdown is not available yet. If you felt it, you can add your report on the USGS website.

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No populated area was estimated to feel noticeable shaking.

After the main event

Aftershocks within 100 km

USGS lists 7 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.2 on November 15, 2022. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,556 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

2021M8.1
South Sandwich Islands
12 Aug 2021 · 62 km away
tsunami
1961M7.7
South Sandwich Islands
5 Sep 1961 · 100 km away
1961M7.7
South Sandwich Islands
8 Sep 1961 · 288 km away
1961M7.5
South Sandwich Islands
1 Sep 1961 · 104 km away
2021M7.5
South Sandwich Islands
12 Aug 2021 · 143 km away

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers