Reviewed by USGS84y ago
M6.8 earthquake in South Sandwich Islands region
Tuesday, November 2, 1943, 18:08:30 UTC · 56.761°S, 26.056°W
A magnitude 6.8 earthquake struck in South Sandwich Islands region on Tuesday, November 2, 1943, 18:08:30 UTC, at a depth of 60.0 km (shallow). It is the strongest earthquake within 300 km since an M6.9 on August 18, 1930.
- Magnitude
- 6.8
- Strong · mw
- Depth
- 60 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 earthquakeDashed circle: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
256 kilotons of TNT
That is about 17 times the Hiroshima bomb. It released about 537 times the energy of a magnitude 5.0.
Tectonic setting
74 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
60 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 100 km
USGS lists 1 M2.5+ earthquake within 100 km in the following 30 days; the largest was M6.2 on November 4, 1943. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 20 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11929 South Sandwich Islands EarthquakeJune 27, 1929 · 256 km NW of this epicenter
- 7.2South Sandwich Islands regionNovember 15, 1910 · 289 km SE of this epicenter
- 6.9South Sandwich Islands regionAugust 18, 1930 · 161 km NW of this epicenter
- 6.9South Sandwich Islands regionSeptember 13, 1921 · 205 km NW of this epicenter
- 6.6South Sandwich Islands regionJuly 21, 1933 · 286 km NW of this epicenter
- 6.5South Sandwich Islands regionApril 21, 1930 · 73 km NE of this epicenter
- 6.5South Sandwich Islands regionDecember 6, 1929 · 263 km NW of this epicenter
- 6.5South Sandwich Islands regionSeptember 17, 1937 · 94 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 1 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1929M8.1
South Sandwich Islands
27 Jun 1929 · 256 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.