Reviewed by USGS67y ago
M7.0 earthquake in South Sandwich Islands region
Monday, December 14, 1959, 23:22:03 UTC · 59.935°S, 26.266°W
A magnitude 7.0 earthquake struck in South Sandwich Islands region on Monday, December 14, 1959, 23:22:03 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M7.0 on March 9, 1943.
- Magnitude
- 7.0
- Strong · mw
- Depth
- 25 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
415 kilotons of TNT
That is about 28 times the Hiroshima bomb. It released about 871 times the energy of a magnitude 5.0.
Tectonic setting
41 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
25 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 M5.8 on December 15, 1959. 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 27 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 · 57 km SW of this epicenter
- 7.2South Sandwich Islands regionNovember 15, 1910 · 160 km NE of this epicenter
- 7.0South Sandwich Islands regionMarch 9, 1943 · 136 km SW of this epicenter
- 7.0South Sandwich Islands regionMarch 21, 1926 · 175 km SE of this epicenter
- 6.7South Sandwich Islands regionJanuary 14, 1936 · 246 km SE of this epicenter
- 6.7east of the South Sandwich IslandsDecember 27, 1949 · 251 km E of this epicenter
- 6.6South Sandwich Islands regionFebruary 15, 1959 · 30 km N of this epicenter
- 6.6South Sandwich Islands regionMarch 25, 1943 · 64 km SW of this epicenter