The tremor hit 70 kilometers east of the coastal city of Arica, which is near the border with Peru, the US agency said.
The quake struck at a depth of 82 kilometers, it added.
Chile is one of the world's most earthquake-prone countries. In the past seven years it has had three quakes of a magnitude greater than eight.
The 1960 Valdivia earthquake in Chile was the strongest quake ever recorded at 9.5 on the magnitude scale, according to the US Geological Survey.
Chile lies on what is known as the Ring of Fire -- an arc of fault lines that circles the Pacific Basin and is prone to frequent earthquakes and volcanic eruptions.