Reviewed by USGS13y ago
M4.4 earthquake in South Sandwich Islands region
Monday, August 12, 2013, 14:23:14 UTC · 60.023°S, 26.458°W
A magnitude 4.4 earthquake struck in South Sandwich Islands region on Monday, August 12, 2013, 14:23:14 UTC, at a depth of 62.5 km (shallow).
- Magnitude
- 4.4
- Light · mb
- Depth
- 63 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
60 tons of TNT
That is about 1/251 of the Hiroshima bomb. A magnitude 5.0 releases about 8 times more energy.
Tectonic setting
4 km
from the nearest mapped plate boundary, between the Australian and Antarctic plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
63 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 609 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.5South Sandwich Islands regionAugust 28, 1933 · 43 km SW of this epicenter
- 7.4east of the South Sandwich IslandsJanuary 2, 2006 · 285 km SE of this epicenter
- 7.3South Sandwich Islands regionSeptember 1, 1961 · 85 km N of this epicenter
- 7.3South Sandwich Islands regionJuly 15, 2013 · 120 km SE of this epicenter
- 7.2South Sandwich Islands regionNovember 15, 1910 · 174 km NE of this epicenter
- 7.2South Sandwich Islands regionOctober 22, 1983 · 90 km SE of this epicenter
- 7.0east of the South Sandwich IslandsOctober 6, 1973 · 284 km E of this epicenter
- 7.0South Sandwich Islands regionJanuary 30, 1987 · 26 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 3 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1961M7.7
South Sandwich Islands
5 Sep 1961 · 227 km away
- 1961M7.5
South Sandwich Islands
1 Sep 1961 · 75 km away
- 1973M7.5
Antarctica
6 Oct 1973 · 284 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.