A swarm of small earthquakes within the Karoo Basin in South Africa has revealed a critically stressed fault that could be perturbed by potential shale gas exploration in the area, according to a new report. The analysis by Benjamin Whitehead of the University of Cape Town and colleagues concludes that the Karoo microseismicity occurred along a buried fault that may extend through sedimentary layers to the crystalline bedrock, which would increase its vulnerability to stresses produced by shale gas exploration.
