SA Japanese seismologists battle quakes

South African and Japanese seismologists are working on a project to combat earthquake risk, the Council for Scientific and Industrial Research (CSIR) says.

"While South Africa is largely stable from a seismic point of view, our deep gold mines are unique earthquake laboratories," spokesman Tendani Tsedu said in a statement.

"Japanese and South African seismologists are working together in these mines in an effort to understand the fundamental physics of earthquakes better and to develop technologies that will mitigate the risks that they pose."

He said the earthquake in eastern Japan on March 11 had been a "sobering" reminder of threat facing those living in tectonically-active regions.

The five-year project was funded by the Japan International Co-operation Agency and the Japan Science and Technology Agency.

It was officially launched in August 2010 and by the end of January 2011, 45 boreholes totalling 1.9 km in length had been drilled at project sites at Ezulwini, Moab-Khotsong and Driefontein gold mines.

Several more holes were still to be drilled and acoustic emission sensors, strain- and tiltmeters, and controlled seismic sources were being installed.

"[This would] monitor the deformation of the rock mass, the accumulation of damage during the earthquake preparation phase, and changes in dynamic stress as the earthquake rupture front propagates," Tsedu said.

CSIR and University of the Witwatersrand geoscientist Professor Ray Durrheim is part of a group of South Africans working on the project.