Inquiry held into geothermal project

Vienna: Swiss prosecutors are investigating a green energy project after it was revealed that it caused earthquakes.

The inquiry was launched after experts confirmed the Deep Heat Mining project to exploit geothermal energy near the north-west border city of Basel had caused tremors measuring 3.3 on the Richter scale.

The project involved injecting large quantities of pressurised water into three-mile-deep boreholes, where underground temperatures reach 200C. The super-heated water is circulated back to the surface where it is used to produce steam and drive a turbine to generate electricity.

Earthquakes

But Geopower Basel, the company behind the scheme, was forced to stop pumping water into the hot rock layer following a series of powerful earthquakes, which were felt up to 16 kilometres away.

Jean Ueberschlag, the mayor of nearby Saint Louis in France, wrote to the Swiss authorities demanding a halt to the experiment. He said: "You don't have the right to play with the safety of our populations."

Prosecutors are now investigating everyone involved in the project to determine possible criminal responsibility, amid allegations that project officials knew there was a risk of triggering earthquakes.

The four quakes, the latest of which took place two weeks ago, caused panic in Basel, Switzerland's third largest city, as people sought shelter from what appeared to be a natural disaster.

Warning

Houses and other property sustained only minor damage but seismologists, who confirmed the quakes were caused by the project, warned the local population that stronger seismic activity could occur even though the project has been temporarily halted.

Basel is one of the areas in Switzerland most prone to seismic activity. In 1356, the city was almost entirely destroyed by a quake of 6.5 on the Richter scale. Swiss prosecutors say that all partners in the scheme could face charges of causing material damages and "spreading fear" among the population.