Drilling a mile into an active deep sea fault zone

Physics Today : For the first time in the history of scientific ocean drilling, scientists have successfully drilled nearly a mile beneath the ocean floor into one of the world’s most active earthquake zones.The experiment, part of the Japanese Integrated Ocean Drilling Program (IODP), was to gather seismic data.The deep-sea drilling vessel Chikyu used a technique called riser drilling to penetrate the upper portion of the Nankai Trough , an earthquake zone located about 36 miles southeast of Japan. The region is a subduction zone in which the Philippine Sea plate is sliding beneath the island.One of the principle investigators, Timothy Byrne of the University of Connecticut, says that the experiment will enable scientists to measure the trough’s stress magnitude and pore pressure, which “are both important to understanding earthquake processes.""Ultimately,” says Demian Saffer, a co-investigator from Pennsylvania State University,"we plan to install long-term observatory systems in these boreholes that will allow us to continuously monitor the geologic formation during the earthquake cycle.”