Reviewed by USGSSouth Africa30y ago
M5.2 earthquake 5 km SSE of Orkney, South Africa
Monday, February 10, 1997, 16:10:28 UTC · 27.022°S, 26.702°E
A magnitude 5.2 earthquake struck 5 km SSE of Orkney, South Africa on Monday, February 10, 1997, 16:10:28 UTC, at a depth of 5.0 km (shallow). It is the strongest earthquake within 300 km since an M5.6 on October 30, 1994.
- Magnitude
- 5.2
- Moderate · mb
- Depth
- 5 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- 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
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
10 km
from the nearest mapped plate boundary, between the Somali and African plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
5 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 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 31 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.128 km N of Maputsoe, LesothoFebruary 20, 1912 · 212 km SE of this epicenter
- 5.712 km WNW of Westonaria, South AfricaMay 14, 1974 · 117 km NE of this epicenter
- 5.66 km S of Welkom, South AfricaOctober 30, 1994 · 112 km S of this epicenter
- 5.55 km NNW of Orkney, South AfricaApril 7, 1977 · 11 km NW of this epicenter
- 5.50 km S of Welkom, South AfricaJanuary 25, 1989 · 107 km S of this epicenter
- 5.35 km SSE of Welkom, South AfricaJune 6, 1992 · 111 km S of this epicenter
- 5.30 km NE of Orkney, South AfricaOctober 28, 1986 · 6 km NW of this epicenter
- 5.28 km WNW of Welkom, South AfricaDecember 8, 1976 · 104 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 31 recorded deaths. The most severe:
- 1997M5.0
Avgold'S Hartebeestfontein Mine
21 Jul 1997 · 20 km away
15 deaths
- 1990M4.0
Charletonville
18 Oct 1990 · 95 km away
10 deaths
- 1976M5.2
South Africa
8 Dec 1976 · 104 km away
4 deathsModerate damage ($1–5M)
- 1990M4.2
Welkom
26 Sep 1990 · 110 km away
2 deathsLimited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.