Labor pains at subduction's birth



The largest earthquake in 12 years has drawn attention to a remote part of the world where the established rules of plate tectonics break down along a jumble of ridges and troughs running from New Zealand almost to Antarctica.

The submarine earthquake occurred May 23 near uninhabited Macquarie Island, about 2000 km southwest of Auckland, New Zealand, in the South Pacific Ocean. It was felt several hundred kilometers away on Campbell Island but caused little damage, despite a surface wave magnitude of 8.3, larger than that of the earthquakes that hit Mexico City in 1985. No identifiable tsunami resulted.