Cape Town, South Africa

The first seismometer in South Africa was installed at Union Observatory in Johannesburg (1910-1972) followed by the installation of a Milne-Shaw seismometer in 1920 at Cape Town Royal Observatory. Prior to 1970, seismic observations were limited to 9 sites. After the devastating 1969 Tulbagh earthquake in Western Cape Province, the South African National Seismograph Network (SANSN) was established. In 1997, SANSN contained 27 stations. Digital stations were installed beginning in 1991. See Saunders et al. (2008)

Stations

The Cape Town, South Africa station was moved in 1934 from the Royal Observatory of the Cape of Good Hope (CGH) to the Department of Mathematics of Cape Town University (CTO, only less than 2 km away), but then again in 1950 and more significantly to Hermanus (HER), ~90 km to the East. All records were filed at the Silverton office of the Council for Geosciences under the label ‘‘Hermanus’’. (Okal, 2015).

Instrumentation

Milne-Shaw horizontal

Recording Medium

Data Availability

Scans from 1921-1980 labelled as “HER”.

See the full list of available scans. Holdings are labelled by the end date of the record. [list]

The Silverton (Pretoria) branch of the Council for Geosciences (South Africa) holds a large collection of analog seismograms, operated at Cape Town between 1920 and 1938.

Contact

For more information about this collection, please contact: < blank >

References

Okal, E. A. (2015). Historical seismograms: Preserving an endangered species. GeoResJ, 6, 53–64. doi: 10.1016/j.grj.2015.01.007

Ou, Qi (2022). Scanned_Seismogram_Holdings_from_CapeTown_Hermanus_end_dates_changed_location, https://docs.google.com/spreadsheets/d/1pUyHyQMMIXvhO0XkS13FqvfHveVoEC_c/edit#gid=1991604385. Last accessed 2022 February 10.

Saunders, Ian, Martin Brandt, Johan Steyn, Dale Roblin, Andrzej Kijko (2008). The South African National Seismograph Network. Seismological Research Letters; 79 (2): 203–210. doi: https://doi.org/10.1785/gssrl.79.2.203