The Biggest Dig; October 2005; Scientific American Magazine; by Tim Hornyak; 3 Page(s)

If you've ever thought about digging a hole to China, a new Japanese ship might be your best bet. Workers have just put the finishing touches on an ocean drilling vessel that is designed to bore to unprecedented depths and attain a long-held goal: penetrating the earth's rocky crust to the mantle.

The poorly understood mantle accounts for about two thirds of the planet's mass and is key in the unseen convection processes linked with tectonic plate motion. For Japan, an archipelago straddling the fractious intersection of at least three crustal plates, the issue is also earthquakes. "Japan is situated on these active planetary processes, and 30 million people actually live on one of the most dangerous or active places on the earth," says Asahiko Taira, director general of the Center for Deep Earth Exploration (CDEX) of the Japan Agency for Marine-Earth Science and Technology, which operates the ship.