Shaky Theories

Living in California, it's strange to have to read the NYTimes to learn about a geothermal project up north of San Francisco that has the distinct possibility of unleashing earthquakes. At first I thought this was just going to be another amateur scientist alarm fest, like how CERN was going to produce a black hole that would consume the earth. But, it seems not. A geothermal project in Basel, Switzerland, using exactly the same technique of drilling miles deep below the bedrock, unleashed earthquakes on the town only two months before the environmental review on this project.

By the time people were getting off work amid rain squalls in Basel on Dec. 8, 2006, Mr. Häring’s problems had already begun. His incision into the ground was setting off small earthquakes that people were starting to feel around the city.

Mr. Häring knew that by its very nature, the technique created earthquakes because it requires injecting water at great pressure down drilled holes to fracture the deep bedrock. The opening of each fracture is, literally, a tiny earthquake in which subterranean stresses rip apart a weak vein, crack or fault in the rock. The high-pressure water can be thought of loosely as a lubricant that makes it easier for those forces to slide the earth along the weak points, creating a web or network of fractures.

Mr. Häring planned to use that network as the ultimate teapot, circulating water through the fractures and hoping it emerged as steam. But what surprised him that afternoon was the intensity of the quakes because advocates of the method believe they can pull off a delicate balancing act, tearing the rock without creating larger earthquakes.

Alarmed, Mr. Häring and other company officials decided to release all pressure in the well to try to halt the fracturing. But as they stood a few miles from the drill site, giving the orders by speakerphone to workers atop the hole, a much bigger jolt shook the room.

“I think that was us,” said one stunned official.

Perhaps surprisingly, there isn't even any dispute about the cause. Because it happened so close to the review of this project, there really wasn't time to take it into account. But, it would seem like a good time to do so now, wouldn't it?