Seismic shift: Can we cloak cities from earthquakes?
来源：未知 作者：禹郓莴 时间：2019-03-28 05:19:00
Ted Soqui/Corbis via Getty Images By Kate Ravilious IT’S the summer of 2012, and in a field outside the French Alpine city of Grenoble, a group of civil engineers are doing what they do best: boring. Each of the 30 or so holes they are drilling into the soft sediment would support a telegraph pole. But Sébastien Guenneau, the researcher directing the operation, has more ambitious plans in mind. He’s come here today to start an earthquake. Guenneau, a physicist at the Fresnel Institute in Marseille, France, is one of a band of researchers aiming to shake up the way we deal with quakes. Rather than designing cities and their buildings to withstand them – with all the cost and potential for failure that implies – they believe we can engineer the ground so that destructive seismic waves never reach cities at all. From underground musical pipes to swaying metal rods to strategically planted trees and, yes, even the right sort of holes bored in the right places, they think some simple tools could help us conquer quakes once and for all. Now they’re setting out to test the idea on a grand scale. Seismic waves come in two types: body waves, which travel underground directly from the source, and surface waves, which ripple along Earth’s surface. These are the most damaging to buildings, turning the ground beneath into a bucking bronco. For the last few thousand years,