Reviewed by USGS13y ago
M4.6 earthquake in South Sandwich Islands region
Wednesday, July 17, 2013, 03:41:08 UTC · 61.387°S, 24.098°W
A magnitude 4.6 earthquake struck in South Sandwich Islands region on Wednesday, July 17, 2013, 03:41:08 UTC, at a depth of 111.4 km (intermediate). It is the strongest earthquake within 300 km since an M5.1 on July 16, 2013.
- Magnitude
- 4.6
- Light · mb
- Depth
- 111 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 earthquake
In context
How big was it, and why here?
Energy released
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
77 km
from the nearest mapped plate boundary, between the Antarctic and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
111 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 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 383 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 · 205 km NW of this epicenter
- 7.4east of the South Sandwich IslandsJanuary 2, 2006 · 142 km E of this epicenter
- 7.3South Sandwich Islands regionSeptember 1, 1961 · 278 km NW of this epicenter
- 7.3South Sandwich Islands regionJuly 15, 2013 · 79 km NW of this epicenter
- 7.2South Sandwich Islands regionNovember 15, 1910 · 253 km N of this epicenter
- 7.2South Sandwich Islands regionOctober 22, 1983 · 108 km NW of this epicenter
- 7.1east of the South Sandwich IslandsAugust 26, 1977 · 294 km NE of this epicenter
- 7.0east of the South Sandwich IslandsOctober 6, 1973 · 151 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 2 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1961M7.5
South Sandwich Islands
1 Sep 1961 · 274 km away
- 1973M7.5
Antarctica
6 Oct 1973 · 151 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.