ANGLOGOLD Ashanti has rejected the possibility that blasting at its mines triggered South Africa’s biggest earthquake since 1969, even as scientists said further investigation was needed before reaching a conclusion.
“The epicentre of the earthquake was significantly further away and down from our current infrastructure so it’s not as a result of blasting done by AngloGold,” chief executive Srinivasan Venkatakrishnan said yesterday.
“The magnitude of this scale cannot be induced by any particular act done by one company.”
His comments on the August 5 quake, judged by the Council for Geoscience as a 5.5 magnitude tremor, contrast with those of experts who say it is too early to know the causes.
The epicentre was about 10km below ground near Orkney in the North West, the US Geological Survey said.
AngloGold’s mines in the region are the world’s deepest, extending to a maximum of about 4km.
The quake might have been triggered by mining, Musa Manzi, a geophysicist at Wits University in Johannesburg, said last week.
“At the moment we can’t tell if it was natural or caused by mining activity,” said Eldridge Kgaswane, a seismologist at the Council for Geoscience.
“We’re studying the earthquake and in a month’s time will have a good idea as to the cause.”
The fact that the deepest mine shafts were shallower than the epicentre did not mean that mining could be ruled out as a cause, the seismologist said.
“Blasting in the vicinity of a big fault could have activated seismic activity,” Kgaswane said yesterday.
AngloGold was restarting its Great Noligwa and Moab Khotsong mines, the two affected by the earthquake, it said yesterday.
At 3km deep, Moab Khotsong had the longest single shaft of any mine in the world, Mike O’Hare, AngloGold’s chief operating officer for South Africa, said.
Venkatakrishnan said: “For every view, or one direction, there will be a contrary view, I’m sure.
“Earthquakes happen in areas where there is no mining taking place. It’s more driven around the geology of the place rather than specifically in relation to mining.”
AngloGold said it had lost about 30 000 ounces of gold output from the stoppage, valued at about $39 million (R415m) at yesterday’s average spot price.
“When we got the news that the epicentre was closer to our mines than any other mines and we had 3 300 people trapped, that was a terrifying day of our lives,” the chief executive said.
“We got the call at 7.30pm saying everyone had been accounted for. That was a relief.” – Bloomberg