South Africa’s push to develop shale gas resources in the Karoo Basin faces fresh scrutiny after scientists identified a previously unknown fault system that could influence future decisions on exploration in the region.

Researchers at the University of Cape Town (UCT) have urged authorities to increase geological monitoring after finding evidence of faults that may be capable of generating earthquakes.

The discovery adds another layer of complexity to efforts to tap into one of the country’s most debated energy resources.

The Karoo Basin has been identified as a potential source of natural gas that could help South Africa diversify its energy mix, reduce reliance on coal and improve long-term energy security.

However, shale gas development has remained controversial because of concerns over water use, environmental damage and possible seismic activity.

The study examined an earthquake swarm near Leeu Gamka in the Western Cape, an area previously regarded as having limited seismic activity.

Since the events began in 2007, the area has recorded at least 66 earthquakes, including one measuring magnitude 4.8 on the Richter scale.

Scientists call for closer monitoring before shale gas development

Scientists from UCT’s Department of Geological Sciences said their findings show that critically stressed faults exist beneath parts of the Karoo Basin.

Lead researcher Benjamin Whitehead said the earthquakes recorded in the region were natural and were not caused by hydraulic fracturing, also known as fracking.

Whitehead said the findings should not stop shale gas exploration but should guide future decisions by helping regulators and energy companies identify areas where additional safety measures may be needed.

He added that global experience shows shale gas activities and wastewater injection can sometimes reactivate existing faults under specific geological conditions.

Karoo gas estimates remain a major source of debate

South Africa’s Petroleum Agency estimates that the Karoo Basin contains about 209 trillion cubic feet (tcf) of technically recoverable shale gas resources, making it one of the country’s largest potential energy reserves.

However, estimates vary widely. A 2017 study by geologists at the University of Johannesburg placed recoverable resources at about 13 tcf, far below earlier projections that ranged from 13 tcf to 390 tcf.

The uncertainty has added to the cautious approach taken by investors and policymakers.

Fracking debate continues as South Africa seeks energy solutions

South Africa’s shale gas plans have faced years of delays after environmental groups challenged exploration efforts over concerns that hydraulic fracturing could harm the Karoo’s sensitive ecosystem.

In 2011, the government suspended new applications for oil and gas reconnaissance permits and exploration rights.

As the country searches for reliable energy sources while managing environmental risks, the latest findings highlight the challenge of balancing economic opportunities from natural gas with the need to protect communities and ecosystems in the Karoo region.