The quake and heavy waves afterward caused flooding in coastal towns, damaged buildings and knocked out power in the worst hit areas of central Chile and shook buildings in the capital city of Santiago about 280 km (175 miles) to the south.
The port of Coquimbo suffered major damage in the quake, which was the strongest in the world this year, Interior Minister Jorge Burgos told a news conference.
President Michelle Bachelet said she planned to travel to the areas worst affected by the quake, the biggest to hit the country since 2010.
“Once again we’re having to deal with another harsh blow from nature,” she said in a televised statement.
Chile is the world’s top copper producer and operations were suspended at two big copper mines.
Copper prices on the London Metal Exchange rose to two-month highs in early Asian trading on worries about supply disruptions.
The quake was felt as far away as Buenos Aires in Argentina.
“It’s been awful. We ran out of the house with our grandchildren and now we are on a hill hoping it will be over soon,” said Maria Angelica Leiva from the coastal town of Navidad.
“It is all very dark, and we just hope the sea hasn’t reached our house,” she said.
Tsunami advisories were issued for parts of South America, Hawaii, California and French Polynesia, although waves were generally expected to be small. As far away as New Zealand, authorities warned of “unusually strong currents” and urged residents in eastern coastal areas to stay out of the water and off beaches.