Local authorities have ordered an evacuation of some coastal areas but there have no immediate reports of injuries or damage.
The U.S. Geological Survey said the powerful quake struck at 6:46 p.m.
local time (2346 GMT) and the epicenter, with a depth of only 10.0 km, is located some 99 km northwest of the mining port of Iquique, near the Peruvian border.