SCIENCE

An American Tsunami?

There's no cause for panic, but the next big wave could be triggered by a fault in the Pacific Northwest

By J. Madeleine Nash

Scientists have known for some time about the 700-mile-long fault off the coast of Washington, Oregon and California, where a wayward slab of the earth's crust known as the Juan de Fuca plate is trying to slide under continental North America. What they didn't know until quite recently was that the juncture where the two plates are locked together can snap violently like a giant spring, unleashing a tsunami as large and terrifying as the one that pummeled South Asia.

U.S. Geological Survey researcher Brian Atwater led the detective work that nailed down the tsunami-rich history of the Cascadia Subduction Zone, finding such clues as fire pits buried under a layer of tsunami sand and linking them to records of what appears to be the same tsunami striking villages in Japan in January 1700.

A bit of subterranean rustling doesn't mean that a great earthquake is imminent, of course. But the tsunami warning signs on local beaches remind us that those who live and play along Cascadia's jagged coast do so at their risk. —from TIME, January 17, 2005

Questions

1. What is the Cascadia Subduction Zone and where is it?

2. How much energy does an earthquake with a magnitude of 9.0 generate?