Cascadia's Fault

April 4, 2011
The recent seismic catastrophe in Japan is a foretaste of a similar cataclysm brewing in America, according to this alarming geological exposé. Thompson, a former Canadian Broadcasting Corporation reporter and documentarian, investigates the Cascadia Subduction Zone, an 800-mile-long fault where the ocean floor slowly grinds away underneath the North American continental plate. The fault has a millennia-long history of causing major quakes, including magnitude-9 monsters and 90-foot waves that could lay waste to Vancouver, Seattle, and dozens of coastal towns. But because no written records of this history exist and the fault has been quiescent since 1700, geologists were unaware of the danger. How they uncovered the violent history of this deceptively placid area, long a subject of academic controversy, is the fascinating scientific detective story at the heart of Thompson's account. He follows along as researchers piece together clues from ocean sediment core samples and tree rings, antique Japanese manuscripts, and laser gadgets and GPS devices that measure the inch-a-year movements of mountain chains; he blanches as their computer models illustrate the devastating impact of tsunamis and the fatal rhythms through which skyscrapers resonate to a temblor's shocks. The result is a lucid, engrossing look at the Earth's subtle dynamicsâand a timely warning about their awesome power very close to home.