The natural disaster, which struck at 11:58 p.m. local time on Tuesday, was centered in water just off New Ireland island, about 44 kilometers (27 miles) northeast of Kokopo on the island of New Britain.
The U.S. Geological Survey said the quake measured magnitude 7.5 and was located 45 kilometers (28 miles) northeast of Kokopo, a remote town with a population of about 26,000.
The Pacific Tsunami Warning Center said there was a threat of tsunami - including possibly for Hawaii.
There were no initial reports of serious damage but the full picture may not become clear until daylight.
Baytown officer fatally shoots woman after struggle over Taser
The police are also trying to locate the person who filmed the shooting and uploaded the content to social media. Garrett then says "no" and continues to stab the victim, forcing the officer to fire one shot at the suspect.
Tim Conway, Star of The Carol Burnett Show, Dead at 85
He got his career start on local TV in Cleveland in the 1950s, where his duties included comedy spots on a late-night movie show. He frequently guest-starred on the most popular shows of the day, including Married with Children and Mad About You .
Malcolm Brogdon Injury: Milwaukee Bucks guard upgraded to 'probable' for Game 5
Giannis Antetokounmpo scored 39 points to lead Milwaukee to the win and Kyrie Irving scored 23 points in the loss for Boston. They were beaten by the better team and it looked like Boston had accepted their fate.
The Pacific Tsunami Warning Centre put the quake at a strength of 7.7. Other countries could see very small tsunami waves.
Papua New Guinea is located on the eastern half of the island of New Guinea, to the east of Indonesia.
A 7.5-magnitude quake hit the rugged highlands region in February 2018 that triggered landslides, burying homes and killing at least 125 people.
The scale of that disaster did not become apparent for days due to PNG's poor communications and infrastructure.