Two earthquakes measuring 6.0 and 5.8 hit an area off the Pacific coast of Chile early Sunday (local time), the US government said.
There were no immediate reports of casualties or damage.
The first tremor occurred about 37 kilometres north north-west of the city of Concepcion, according to the US Geological Survey.
It was followed an hour and a half later by a 6.0 tremor 25 kilometres north north-west of the same city, which was heavily damaged by an 8.8-magnitude quake nearly a year ago.
The reading was based on the open-ended Moment Magnitude scale now used by US seismologists which measures the area of the fault that ruptured and the total energy released.