Image Courtesy University of California Berkeley Seismological Laboratory UC Berkeley's early-warning system detects more benign fast-moving shock waves (yellow) in advance of slower vibrations, which cause more damage (red). Related Links: Northern California Earthquake Causes an Estimated $1 Billion in Damage Earthquake Warning System Makes Every Second Count An earthquake-detection system under development by the University of California's Berkeley Seismological Laboratory proved its mettle on Aug. 24 by issuing a warning 10 seconds before a magnitude-6 temblor struck south of Napa, Calif. The alert could have gone out 2.5 seconds sooner if the ShakeAlert system, based on Japan's primary-wave detection
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.