1969 Tulbagh earthquake
  Cape Town  | |
| UTC time | 1969-09-29 20:03:30 |
|---|---|
| ISC event | 805003 |
| USGS-ANSS | ComCat |
| Local date | September 29, 1969 |
| Local time | 22:03 SAST |
| Magnitude | 6.3 Mw |
| Depth | 15 km (9 mi) |
| Epicenter | 33°16′05″S 19°23′10″E / 33.268°S 19.386°E |
| Type | Strike-slip |
| Max. intensity | MMI VIII (Severe) |
| Landslides | Many rockslides |
| Casualties | 12 dead |
The 1969 Tulbagh earthquake occurred at 20:03:33
Tectonic setting
The Western Cape lies on the Cape Fold Belt, which is characterised by many thrust faults. Some of these thrust faults were reactivated during Cretaceous rifting as extensional faults, such as the Worcester Fault, which comes to the surface close to the epicentral area, but does not appear to be active.[1]
Earthquake
The earthquake was estimated to have a magnitude of 6.3 ML.[1] The ISC-GEM catalogue records it as 6.3 Mw. The focal mechanism shows that the earthquake was a result of strike-slip faulting, either sinistral movement on a NW-SE trending fault or dextral movement on a NE-SW trending fault. As the zone of aftershocks was elongated in a NW-SE direction, the NW-SE plane is regarded as the fault responsible. There is no evidence of a surface fault trace and it has not been possible to tie the earthquake to movement on a known fault structure. However, faults of similar orientation are known from nearby areas.[1]
Aftershocks
The main-shock was followed by a long series of aftershocks. The largest aftershock occurred nearly six months later on April 14 1970 and had a magnitude of 5.7 Mw .[1]
Damage
Damage was particularly severe in the towns of Ceres, Tulbagh, Wolseley and
The earthquake severely affected Church Street in Tulbagh, which was renowned for its 18th to 20th-century buildings in
Aftermath
The buildings in Church Street were restored, initially by the National Committee for the Restoration of Historic Buildings in Tulbagh and its Environment, and later by the Tulbagh Valley Heritage Foundation.[4]
See also
References
- ^ S2CID 130174309.
- .
- S2CID 140686381.
- ^ a b "From the ashes of South Africa's worst earthquake rise the old buildings of Tulbagh". The Heritage Portal. Archived from the original on 2019-03-05. Retrieved 2019-10-03.