Reviewed by USGS4y ago
M4.6 earthquake in South Sandwich Islands region
Sunday, February 20, 2022, 00:45:57 UTC · 58.971°S, 23.821°W
A magnitude 4.6 earthquake struck in South Sandwich Islands region on Sunday, February 20, 2022, 00:45:57 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M4.8 on February 19, 2022.
- Magnitude
- 4.6
- Light · mb
- Depth
- 10 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
11 km
from the nearest mapped plate boundary, between the Sandwich and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
10 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event 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 PAGER estimate is available for this event.
After the main event
Aftershocks within 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,233 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.12021 South Sandwich Islands EarthquakeAugust 12, 2021 · 107 km NW of this epicenter
- 7.5South Sandwich Islands regionAugust 12, 2021 · 171 km NW of this epicenter
- 7.5South Sandwich Islands regionAugust 28, 1933 · 232 km SW of this epicenter
- 7.4east of the South Sandwich IslandsJanuary 2, 2006 · 253 km SE of this epicenter
- 7.3South Sandwich Islands regionSeptember 1, 1961 · 173 km W of this epicenter
- 7.3South Sandwich Islands regionJuly 15, 2013 · 221 km S of this epicenter
- 7.2South Sandwich Islands regionNovember 15, 1910 · 17 km SW of this epicenter
- 7.2South Sandwich Islands regionOctober 22, 1983 · 209 km SW of this epicenter
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 · 106 km away
tsunami
- 1961M7.7
South Sandwich Islands
5 Sep 1961 · 214 km away
- 1961M7.5
South Sandwich Islands
1 Sep 1961 · 206 km away
- 1973M7.5
Antarctica
6 Oct 1973 · 241 km away
- 2021M7.5
South Sandwich Islands
12 Aug 2021 · 173 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.