Thursday 7 March 2019

Magnitude 3.8 Earthquake near Johannesburg, South Africa.

The South African Council for Geosciences recorded a Magnitude 3.8 Earthquake about 20 km to the southeast of the city of Johannesburg in Gauteng Province, slightly after 11.30 am local time (slightly after 9.30 am GMY) on Thursday 7 March 2019. There are no reports of any damage or casualties associated with this event, though many people reported feeling it in the Johannesburg area. 

The approximate location of the 7 March 2019 Johannesburg Earthquake. USGS.

 Earthquakes of any size are relatively rare in South Africa and because of this rarity it is hard to make precise judgements about the cause of quakes in South Africa, due to a paucity of data. Northwestern South Africa is close the southern end of the Great Rift Valley exits the continent and passes out under the Indian Ocean on the coast of Mozambique. The Great Rift Valley is slowly splitting the African Plate in two allow a line from the Red Sea through Ethiopia, and which includes the great lakes and volcanoes of east-central Africa. This has the potential to open into a new ocean over the next few tens of millions of years, splitting Africa into two new, smaller, continents; Nubia to the west and Somalia to the east.

 Movement on the African Rift Valley, with associated volcanoes. Rob Gamesby/Cool Geography.

Witness statements can help geologists to understand Earthquakes and the geological processes that cause them; if you felt this quake (or if you were in the area but did not, which is also useful information) you can report it to the South African Council for Geoscience here.

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