The quake was centered nearly 600 kilometers from the city of Puerto Quellon at 5:49 a.m. local time.
Geologists said the quake was relatively shallow, but there was no danger of a tsunami.
Chile is highly earthquake-prone. A magnitude-8.8 quake struck Chile in 2010 and caused a tsunami that obliterated much of the coastal downtown of the central Chilean city of Constitucion. The quake killed more than 500 people and destroyed 220,000 homes.
The Associated Press contributed to this story.