A Crack in the Edge of the World

As indicated by its subtitle, A Crack in the Edge of the World is focused on the earthquake of 1906, which destroyed much of the young city of San Francisco. That earthquake is easily worthy of a book of this length (more than 450 pages), both for the magnitude of destruction and for the human drama that accompanied it. Indeed, there have been many books already published on the topic, including memoirs of survivors, clinical accounts of the seismic causes, more lurid semifictionalized accounts of suffering and heroism, collections of photographs, and more engineering studies of how different types of structures fared. (This book lists some of these books in an appendix of “suggestions for further reading.”)

While this book uses the 1906 San Francisco earthquake as a focal point, its temporal and geographic scope is much broader, extending across millennia and continents. Indeed, the earthquake is not so much the reason for the book as it is the lens for looking at the sometimes-dry and always-esoteric science of plate tectonics, which concerns movements in the earth’s crust. Introduced in the 1960’s, the theory of plate tectonics, now widely accepted, explains earthquakes and other seismic events as being caused by the movement of continent-sized segments of the earth’s surface. These “plates” are in constant (albeit gradual) motion, riding on the earth’s mantle. The location where the edges of two plates meet is a fault line, along which slippage occurs and, occasionally, earthquakes.

There are obvious advantages to understanding the behavior of these plates, most important for the location and engineering of buildings and other structures. Clues that help to illuminate plate behavior are found in all manner of geological formations: mountain ranges, rivers, volcanoes, rock outcroppings, soils, and so forth. These point to past seismic events and may help in the prediction of future ones. Though there is general acceptance of the concept of enormous fragments of the earth’s crust slowly drifting on the sea of molten rock that is the earth’s mantle, the science of earthquake prediction is still in its infancy. For the time being, scientists are much better at explaining why and how an earthquake has occurred, than when or how it will occur.

The author, Simon Winchester, leads the reader on a journey across the North American plate, which encompasses not only North America but also part of the Atlantic Ocean, the western end of Eurasia, and Greenland. Winchester uses this trip, which he actually took, as a rough guide for a travelogue that goes on for about one hundred pages. At various points along the waysuch as Charleston, South Carolina, and Meers, MissouriWinchester describes not just the local geography but how that geography and infrastructure and society were shaped in part by geological forces over time. These are not dispassionate history lectures but engaging stories of people, places, and societies, laced with a healthy dose of trivia and vignettes about such things as how place names were conferred, how simple lives were affected by the insuperable forces of nature, and how Winchester’s car responded when the road inclined upward to pass over a mountain.

The result is a story that is not quite a stream of consciousness but a far cry from a linear narrative. Winchester’s constant shifting of time, place, and focus are not disorienting, thanks to his comfortable grasp of storytelling. He is an engaging and skilled writer, effortlessly balancing his prose on the edge between authoritative explanation and entertaining description. In those rare cases in which he deems a detail too off-point for the flow of his story, Winchester employs a footnote. One seldom reads more than three or four pages without running into one of these. Overall, Winchester’s approach works as a way to connect the social, cultural, physical, temporal, and geographical facets of North...

(The entire section is 1612 words.)