Reviewed by USGS10y ago
M5.2 earthquake in South Georgia Island region
Saturday, September 17, 2016, 18:00:35 UTC · 55.244°S, 31.482°W
A magnitude 5.2 earthquake struck in South Georgia Island region on Saturday, September 17, 2016, 18:00:35 UTC, at a depth of 10.0 km (shallow). USGS received 1 “Did You Feel It?” report, with a maximum reported intensity of II (weak). It is the strongest earthquake within 300 km since an M5.3 on September 16, 2016.
- Magnitude
- 5.2
- Moderate · mb
- Depth
- 10 km
- Shallow
- Felt reports
- 1
- Max intensity II
- 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
951 tons of TNT
That is about 1/16 of the Hiroshima bomb. It released about 2 times the energy of a magnitude 5.0.
Tectonic setting
55 km
from the nearest mapped plate boundary, between the Scotia and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
10 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
Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.
| Place | Intensity | Reports | Distance |
|---|---|---|---|
| Grytviken, South Georgia, Falkland Islands | II · Weak | 1 | 344 km |
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 26 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.0 on September 24, 2016. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.2South Georgia Island region10y ago · 41 km W of this epicenter
- 4.5South Georgia Island region10y ago · 34 km NW of this epicenter
- 4.3South Sandwich Islands region10y ago · 53 km E of this epicenter
- 4.5South Georgia Island region10y ago · 32 km NW of this epicenter
- 4.4South Georgia Island region10y ago · 1 km NE of this epicenter
- 4.8South Sandwich Islands region10y ago · 65 km NE of this epicenter
- 4.9South Sandwich Islands region10y ago · 68 km NE of this epicenter
- 5.0South Sandwich Islands region10y ago · 72 km NE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 588 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 · 136 km E of this epicenter
- 7.8South Sandwich Islands regionMay 26, 1964 · 268 km SE of this epicenter
- 7.4South Georgia Island regionAugust 19, 2016 · 25 km W of this epicenter
- 7.1South Sandwich Islands regionSeptember 8, 1961 · 285 km SE of this epicenter
- 6.9South Sandwich Islands regionAugust 18, 1930 · 229 km E of this epicenter
- 6.9South Sandwich Islands regionSeptember 13, 1921 · 183 km E of this epicenter
- 6.9South Sandwich Islands regionSeptember 6, 2004 · 159 km E of this epicenter
- 6.9South Sandwich Islands regionJune 29, 2014 · 199 km E 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 · 136 km away
- 1961M7.7
South Sandwich Islands
8 Sep 1961 · 286 km away
- 2016M7.4
South Sandwich Islands
19 Aug 2016 · 25 km away · intensity III
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.