The bigger quake, at a depth of about 235 miles, was about 68 miles northwest of New Ireland, the U.S. Geological Survey reported.
The 6.8-magnitude quake occurred about 2 hours later near Kandrian in West New Britain. It was about 38 miles deep.
Radio New Zealand didn't report any damage or injuries from either quake.
A tsunami warning was not issued.
Caroline Berg Eriksen: Soccer player's wife triggers debate with post-birth selfie
NY rabbi using karate to attack the 'knockout game'