Ore-inspiring: War against illegal miners goes hi-tech
Scientists from Council of Geoscience to use satellites, aircraft, radar and lasers to map tunnels
The government, in the war against illicit mining, has turned to science to fight illegal miners operating across thousands of kilometres of the country’s underground.
The battle, to be waged across SA’s economic hub Gauteng, Mpumalanga, North West and the Free State, is being driven by a team of 10 scientists from the Council of Geoscience (CGS).
Armed with aircraft, satellites, ground-penetrating radar, lasers and specialised sensors, the specialists are mapping out vast areas of the country that are being undermined by an estimated 30,000 illegal gold miners.
The Sunday Times recently revealed how Johannesburg mayor Herman Mashaba had been pleading for a year for the national government to intervene in illegal mining, which is threatening to destroy the metro’s critical infrastructure. Mineral resources minister Gwede Mantashe then announced last month that a study would be conducted into the extent of the threat of illegal mining in the country.
The scientists’ mission includes determining the length and breadth of a rabbit warren of tunnels illegal miners work in to steal gold ore.
Council spokesperson Mahlatse Mononela said that while the CGS had been aware of the illegal mining phenomenon for a long time, “the scale of these operations has increased dramatically in recent years”.
She said that in 2010 the CGS commissioned a study that assessed subsidence risk and provided a hazard analysis in the Central Rand area.
“Hazard maps of undermined ground in the Witwatersrand, which extended from Mogale City, Krugersdorp, Roodepoort through to Springs and then south to Heidelberg, were drawn up.
“Since 2013 the CGS has deployed instruments that collect seismic data in the Central Rand region.”
Mononela said the scientists, including engineers and specialists in geohazards, engineering and remote sensing, were collecting LiDAR (light detection and ranging) data and information, including high-resolution aerial images.
LiDAR involves the use of lasers to sample Earth’s surface to produce highly accurate measurements.
Mononela said the LiDAR data had allowed for the mapping of illegal and outcrop mining and associated ground subsidence.
The scientists would use specialised radar, which could be fitted to aircraft, to detect any deformation to the earth’s surface, “which could be related to mine-related ground collapses”.
Mononela added tests would also be conducted to map out cavities in areas affected by illegal mining, as well as any tunnel systems.
“The study will assess and monitor ground stability in Gauteng and nationally.
“It will also monitor explosive signals to determine their location and to differentiate between normal mining-related activities and those related to blasting that happens outside mining blasting schedules.”
She said that through a network of satellites that monitor seismic activity over southern Africa, the scientists would analyse areas where suspected illegal mining occurred.
“The work, especially into earthquakes and tremors, and whether they are caused by legitimate or illegal mining activities, is a difficult task which requires collaboration with active gold-mining companies.”