Ferreting Out the Hidden Cracks In the Heart of a Continent

摘要

Deep beneath the central United States, researchers find signs of buried faults that have triggered earthquakes in the past-and may still be kicking Two hundred years ago, large earthquakes shook the central United States, near what was then the tiny town of New Madrid, Missouri. The shaking on 16 December 1811 was felt all the way to the East Coast. Two more earthquakes followed in January and February. Magnitude estimates for the largest quake have ranged from 6.8 to as high as 8.