Earth & Sky Radio Series

April 28, 2008

By Jorge Salazar

Scientists have drilled closer than ever into an active earthquake zone.

Harold Tobin: We know that there are future magnitude 8 earthquakes coming.

That’s geophysicist Harold Tobin of the University of Wisconsin-Madison. He’s chief scientist with the Japanese research vessel called the Chikyu, which drilled 1.4 kilometers, or nearly a mile into the Nankai trough off the coast of Japan.

Harold Tobin: What we want to do is try to use that as essentially a field laboratory to study the earthquake process and maybe help us understand how to know when earthquakes are coming or what makes big ones big, small ones small, and the differences between earthquakes.

Tobin and colleagues have taken three-dimensional images of stresses inside the quake zone.

Harold Tobin: We have a very sophisticated drill pipe, actually, that has sensors embedded in it. And those sensors can measure properties of the rock. We can also take core samples of the rocks. We bring them up on the ship, and then there’s a sophisticated laboratory where the geologists can study those core samples.

The holy grail of earthquake science, Tobin said, is to be able to predict the day, and even the time when a major earthquake might occur. But there’s a long way yet to go.

Harold Tobin: The real point that we’re at right now is to get into these faults and learn enough about them to understand whether earthquakes are in fact even predictable, whether anything that’s measurable takes place far enough in advance to see it, or not.