Reviewed by USGS18y ago
M4.3 earthquake in South Sandwich Islands region
Saturday, August 23, 2008, 03:29:14 UTC · 58.077°S, 22.065°W
A magnitude 4.3 earthquake struck in South Sandwich Islands region on Saturday, August 23, 2008, 03:29:14 UTC, at a depth of 46.7 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 47 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 earthquake
In context
How big was it, and why here?
Energy released
43 tons of TNT
That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.
Tectonic setting
43 km
from the nearest mapped plate boundary, between the Pacific and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
47 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 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 517 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.2South Sandwich Islands regionNovember 15, 1910 · 158 km SW of this epicenter
- 7.2South Sandwich Islands regionDecember 27, 1991 · 299 km NW of this epicenter
- 7.1east of the South Sandwich IslandsAugust 26, 1977 · 175 km SE of this epicenter
- 7.0South Sandwich Islands regionJune 30, 2008 · 17 km S of this epicenter
- 6.8South Sandwich Islands regionNovember 2, 1943 · 280 km NW of this epicenter
- 6.8South Sandwich Islands regionFebruary 23, 2008 · 116 km NW of this epicenter
- 6.7South Sandwich Islands regionDecember 31, 1963 · 295 km NW of this epicenter
- 6.7South Sandwich Islands regionJanuary 10, 1993 · 274 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 1 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1961M7.7
South Sandwich Islands
5 Sep 1961 · 291 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.