Earthquake Causes Tsunami. Energy accumulates in the overriding plate until it exceeds the frictional forces between the two stuck plates. When this happens, the overriding plate snaps back into an unrestrained position. This sudden motion is the cause of the tsunami - because it gives an enormous shove to the overlying water.
Ajo is in the Sonoran Desert, tucked away in Western Pima County in Arizona, about 120 miles southwest of Phoenix and 130 miles west of Tucson.
High-grade native copper made Ajo the first copper mine in Arizona. Soon the Arizona Mining & Trading company, formed by Peter R. Brady, a friend of Childs, worked the rich surface ores, shipping loads around Cape Horn for smelting in Swansea, Wales, in the mid-1880s.