Reviewed by USGSSaint Helena3y ago
M5.8 earthquake 81 km ENE of Georgetown, Saint Helena
Wednesday, October 19, 2022, 15:03:02 UTC · 7.743°S, 13.695°W
A magnitude 5.8 earthquake struck 81 km ENE of Georgetown, Saint Helena on Wednesday, October 19, 2022, 15:03:02 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). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M5.8 on August 22, 2020.
- Magnitude
- 5.8
- Moderate · mww
- Depth
- 10 km
- Shallow
- Felt reports
- 1
- Max intensity II
- Est. shaking
- IV
- Light (ShakeMap)
- PAGER alert
- Green
- Impact estimate
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
8 kilotons of TNT
That is about 1/2 of the Hiroshima bomb. It released about 16 times the energy of a magnitude 5.0.
Tectonic setting
18 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
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 |
|---|---|---|---|
| Georgetown, Ascension, Saint Helena | II · Weak | 1 | 85 km |
USGS PAGER estimate
Who was exposed to shaking
Modelled from the ShakeMap and population data. Alert level green: low likelihood of casualties and damage.
- IV · Light shaking
- 1,100 people
Estimated shaking in nearby towns
- GeorgetowncapitalPopulation 538IV · Light
After the main event
Aftershocks within 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 99 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 · 163 km S of this epicenter
- 6.1245 km ENE of Georgetown, Saint HelenaNovember 8, 1922 · 167 km NE of this epicenter
- 6.0221 km ENE of Georgetown, Saint HelenaAugust 10, 2011 · 142 km NE of this epicenter
- 6.0206 km NE of Georgetown, Saint HelenaMarch 7, 2001 · 135 km NE of this epicenter
- 5.9Ascension Island regionMarch 27, 1952 · 255 km E of this epicenter
- 5.8178 km ENE of Georgetown, Saint HelenaAugust 22, 2020 · 101 km NE of this epicenter
- 5.7126 km ENE of Georgetown, Saint HelenaJuly 12, 2001 · 49 km NE of this epicenter
- 5.7249 km ENE of Georgetown, Saint HelenaMarch 29, 1964 · 169 km NE of this epicenter