Reviewed by USGSSaint Helena25y ago
M4.3 earthquake 188 km ENE of Georgetown, Saint Helena
Friday, July 27, 2001, 09:20:05 UTC · 7.152°S, 12.892°W
A magnitude 4.3 earthquake struck 188 km ENE of Georgetown, Saint Helena on Friday, July 27, 2001, 09:20:05 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 10 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
3 km
from the nearest mapped plate boundary, between the African 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
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 56 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.1144 km SSE of Georgetown, Saint HelenaMarch 10, 1947 · 257 km SW of this epicenter
- 6.1245 km ENE of Georgetown, Saint HelenaNovember 8, 1922 · 57 km NE of this epicenter
- 6.0206 km NE of Georgetown, Saint HelenaMarch 7, 2001 · 38 km N of this epicenter
- 5.9Ascension Island regionMarch 27, 1952 · 157 km E of this epicenter
- 5.9Ascension Island regionApril 30, 1932 · 231 km NE of this epicenter
- 5.8Ascension Island regionJune 7, 1961 · 234 km NE of this epicenter
- 5.7126 km ENE of Georgetown, Saint HelenaJuly 12, 2001 · 62 km SW of this epicenter
- 5.7249 km ENE of Georgetown, Saint HelenaMarch 29, 1964 · 63 km E of this epicenter