Free State hit by earthquake but tremors did not cause much damage

The Council for Geoscience (CGS) has confirmed that an earthquake was felt in the Free State on Thursday, about 60km south of Bloemfontein.

The quake happened just before 9am.

According to CGS, the earthquake registered a preliminary 3.6 on the local magnitude scale as recorded by the South African Seismograph Network.

“The epicentre was located at about 60km south of Bloemfontein, in the Biesiefontein area,” it said.

The CGS also encouraged the public to record their experiences using an online questionnaire on its website.

READ MORE: People’s alarm turns to excitement after KZN tremor

Volcano Discovery reported that the quake was not felt by many people and did not cause any damage.

KZN earthquakes

South Africa has experienced relatively frequent seismic activity in recent times.

In November last year, the CGS confirmed two earthquakes in KwaZulu-Natal.

The council reported that the first earthquake registered a “preliminary magnitude of 3.9 on the local magnitude scale as recorded by the South African Seismograph Network (SANSN)”.

The earthquake’s epicentre was located in KZN’s Mnkangala region, roughly 40km north of Kokstad.

The second tremor also registered 3.9 on the local magnitude scale, the SANSN confirmed.

This earthquake’s epicentre was located approximately 40km north-east of Greytown and 30km east of Tugela Ferry in KZN.

During the same period, there were reports that a 4.2 magnitude tremor was felt in areas around Johannesburg, including Westonaria.

Expert weighs in

Speaking to Weekend Witness at the time, Doctor Mayshree Singh, a land surveying lecturer at the University of KwaZulu-Natal, explained that a seismic event is also interchangeably referred to as an earthquake or an earth tremor.

Singh explained that an earthquake occurs when there is a release of accumulated stress and strain in a region.

She also said this would generally occur at an existing plane of weakness like a rock mass fracture or an existing geological fault plane.

Singh added that these events happen when a release of energy occurs in the form of an underground explosion and that energy is released in the form of a shockwave.

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