Reviewed by USGSSouth Africa57y ago
M6.3 earthquake 15 km NNE of Ceres, South Africa
Monday, September 29, 1969, 20:03:30 UTC · 33.234°S, 19.351°E
A magnitude 6.3 earthquake struck 15 km NNE of Ceres, South Africa on Monday, September 29, 1969, 20:03:30 UTC, at a depth of 12.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 6.3
- Strong · mw
- Depth
- 12 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- IX
- Violent (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
43 kilotons of TNT
That is about 3 times the Hiroshima bomb. It released about 89 times the energy of a magnitude 5.0.
Tectonic setting
875 km
from the nearest mapped plate boundary, between the Somali and African plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
12 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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists no earlier M5.0+ earthquakes within 300 km.
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 3 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 12 recorded deaths. The most severe:
- 1969M6.3
Cape Province
29 Sep 1969 · 5 km away · intensity IX
12 deaths$24 million damage
- 1969M5.8
Tulbagh
5 Oct 1969 · 28 km away
Moderate damage ($1–5M)
- 1809
Cape Of Good Hope
4 Dec 1809 · 110 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.