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.
Arizona was admitted as a State on February 4, 1912. In 1850 present-day Arizona had no census coverage. The 1860 population is for Arizona County, New Mexico Territory, which comprised most of present-day Arizona south of the Gila River. Northern and central Arizona first had census coverage in 1870.