Reviewed by USGS63y ago
M6.0 earthquake in South Sandwich Islands region
Wednesday, May 27, 1964, 00:56:45 UTC · 55.952°S, 27.455°W
A magnitude 6.0 earthquake struck in South Sandwich Islands region on Wednesday, May 27, 1964, 00:56:45 UTC, at a depth of 125.0 km (intermediate). It is the strongest earthquake within 300 km since an M7.8 on May 26, 1964.
- Magnitude
- 6.0
- Moderate · mw
- Depth
- 125 km
- Intermediate
- 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: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
13 kilotons of TNT
That is about the energy of the Hiroshima bomb. It released about 28 times the energy of a magnitude 5.0.
Tectonic setting
84 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: intermediate
125 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 75 km
USGS lists 3 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M6.0 on May 29, 1964. 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 49 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 · 135 km NW of this epicenter
- 7.8South Sandwich Islands regionMay 26, 1964 · 43 km S of this epicenter
- 7.1South Sandwich Islands regionSeptember 8, 1961 · 43 km S of this epicenter
- 6.9South Sandwich Islands regionAugust 18, 1930 · 37 km NW of this epicenter
- 6.9South Sandwich Islands regionSeptember 13, 1921 · 84 km NW of this epicenter
- 6.8South Sandwich Islands regionNovember 2, 1943 · 125 km SE of this epicenter
- 6.8South Sandwich Islands regionJanuary 30, 1963 · 81 km NW of this epicenter
- 6.7South Sandwich Islands regionDecember 31, 1963 · 107 km SE 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:
- 1929M8.1
South Sandwich Islands
27 Jun 1929 · 135 km away
- 1961M7.7
South Sandwich Islands
5 Sep 1961 · 229 km away
- 1961M7.7
South Sandwich Islands
8 Sep 1961 · 36 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.