Marking the New Madrid earthquake’s 200th anniversary, officials are planning two big preparedness exercises. On Sept. 30, James M. Wilkinson, executive director of the Central U.S. Earthquake Consortium, Memphis, told a Senate hearing his group will hold the Great Central U.S. ShakeOut on April 28. Then, in May, the Federal Emergency Management Agency will simulate and study a quake in the New Madrid zone.
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.