The magnitude 7.5 tremor struck about 11pm Tuesday, local time (1am Wednesday, NZT) at a depth of 10 kilometres, according to the US Geological Survey.
It was centred about 40 kilometres off the coast of New Britain island, which sits in an archipelago to the north of the New Guinea mainland.
"It was very, very violent," said Frank Kilaur, a sergeant at the Rabaul police station, who said the town's electricity had been cut off.
"At the moment there's no damage, but we have to wait until daylight, we're in pitch black right now."