South African earthquake not caused by mining

The earthquake that rocked the Stilfontein area in North West was not caused by mining activities, DRDGold mine company said on Thursday.

"We have no current mining activities within three kilometres of yesterday's (Wednesday) earthquake," said company chief executive Mark Wellesley-Wood.

His contention had scientific backing with the Council for Geoscience saying it was "almost impossible" for the earthquake to have been caused by mining.

Dr Andrzej Kijko, head of the seismology unit at the council said "it's almost impossible that the release of this kind of energy would be caused by mining".

"Although we are calling it mining-related, it does not mean it was caused by mines," he said.

Kijko said there were "significant residual tectonic stresses" in the area, which mining activity had somehow triggered.

The Council for Geoscience registered the quake at a magnitude of 5.3 on the Richter Scale, making it the largest recorded earthquake in South Africa since 1969.

A quake measuring 6.3 that struck the Tulbach area in 1969 had been 30 times stronger, Kijko said.

The United States Geological Survey registered the quake's epicentre at a depth of 15 kilometres below the surface.

Wellesley-Wood said DRDGold's own measurements suggested a point of origin approximately two kilometres below surface, in a fault which traverses the Stilfontein area.

DRDGold noted that the mining areas affected by the quake were properly supported according to mine standards.

"However as a result of the extent of the event, infrastructure sustained serious damage and various rockfalls occurred," said Wellesley-Wood.

He also thanked all who were involved in the rescue operations which resulted in the evacuation of 3 198 miners.

One miner remains unaccounted for while one died from injuries, 20 were treated in hospital and another 20 sustained minor injuries.

"Any one miner who is killed whilst on duty is one too many," said Tim Kruger, spokesperson for trade union United Association of South Africa (UASA) who added that the union had accepted that "the earthquake... was unpredictable and unpreventable".

Kruger commended the "wonderfully courageous" rescue team members who managed to evacuate thousands of miners through eight or nine other tremors in a relatively short period of time "endangering their own lives in the sometimes unstable rock formations".

While production at seven of the mine's shafts had returned to normal, shaft number five, in which 42 miners were trapped until late Wednesday night, remained closed.

The shaft accounted for about 11 percent of North West Operations gold production and suffered serious damage.

Acting Minerals and Energy Minister Buyelwa Sonjica visited injured employees at the mine's Duff Scott Hospital and number five shaft on Thursday.

She complimented DRDGold's staff on the efficiency with which the rescue of employees was completed.

The Department of Mineral and Energy Affairs would conduct an investigation into the matter and DRDGold emphasised its commitment to cooperate in the investigation.

UASA would also form part of the investigating team.

"We will most certainly keep an open mind to exploring ways and means of improving the safety of mine workers even further. We consistently push for a balance between profit and a safe working environment," said Kruger.

DRDGold has notified its insurers of the event and all affected employees and their families were being provided with access to counselling services.

North West Premier Edna Molewa visited Klerksdorp on Thursday afternoon to assess the damage caused the earthquake.

She said the provincial government was ready to provide assistance within its available resources.