Guidebook to world of tremors, earthquakes

The book under review deals with questions that could have been ripped from recent headlines disasters, emergency preparedness and government response. Geologist Simon Winchester's latest book is about the San Francisco earthquake of April 18, 1906.

The quake took more than 3,000 lives, demolished both the shacks of the poor and city hall (ornate but shoddily built) with even-handed indifference. Severed power-lines and gas-pipes, started blazes all over the city, uniting into a fire-storm which raged for three days. But the book is not just about an event. Winchester provides a virtual guidebook to the world of tremors and earthquakes and the geological conditions that produce them.He goes for a bigger picture of our vibration-prone planet, from the Indian-Asian plate boundary (site of the recent disaster in Kashmir) to the shaky slopes of the Andes. There is also a survey of the North American continental plate, from its eastern edge in lava-spewing Iceland to its unpredictable middle to its western edge along the us Pacific coast. He gives brisk accounts of the rise of plate-tectonic theory, as well as the emergence of a "New Geology" as better understandings of the American West's rugged topography were achieved.

The inquiry leads him to the San Andreas Fault geological fault that runs a length of roughly 1,300 km through western and southern California. The fault sends out sub-faults, heads out to sea, returns to land, splits, reunites and finally vanishes a few miles short of Brawley, California. By geological standards the fault moves quickly; the Pacific plate slips northward along the face of the North American plate at pace of 1.3 inches per year. Sometimes it jams. Then pressure accumulates until its pent-up force is released, which is what happened on April 18, 1906.

Winchester tosses in some social history of California and its adjoining areas, and shows how early settlers there had no idea what an active seismic zone they'd chosen as their home. He traces unexpected connections between the 1906 quake and phenomena such as the rise of the Pentecostalist movement and the birth of environmentalism. The book is sometimes a little too breezy for its own good. But it's a rewarding read nevertheless.