Reviewed by USGS68y ago
M6.5 earthquake in South Sandwich Islands region
Sunday, February 15, 1959, 03:59:30 UTC · 59.572°S, 25.764°W
A magnitude 6.5 earthquake struck in South Sandwich Islands region on Sunday, February 15, 1959, 03:59:30 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M6.7 on December 27, 1949.
- Magnitude
- 6.5
- 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
71 kilotons of TNT
That is about 5 times the Hiroshima bomb. It released about 150 times the energy of a magnitude 5.0.
Tectonic setting
55 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
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 M6.6 on February 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 26 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 · 106 km SW of this epicenter
- 7.2South Sandwich Islands regionNovember 15, 1910 · 115 km NE of this epicenter
- 7.0South Sandwich Islands regionMarch 9, 1943 · 181 km SW of this epicenter
- 7.0South Sandwich Islands regionMarch 21, 1926 · 186 km SE of this epicenter
- 6.7South Sandwich Islands regionJanuary 14, 1936 · 243 km SE of this epicenter
- 6.7east of the South Sandwich IslandsDecember 27, 1949 · 230 km E of this epicenter
- 6.6South Sandwich Islands regionMarch 25, 1943 · 113 km SW of this epicenter
- 6.5South Sandwich Islands regionJuly 17, 1935 · 72 km S of this epicenter