A 6.5 magnitude earthquake struck off the coast of Papua New Guinea's Bougainville island on Tuesday, but there were no reports of damage or sea level changes.
The quake's epicenter was 78 miles (125 km) west of Arawa on Bougainville at a depth of 46.4 miles (75 km), the US Geological Survey said in Washington on Monday.
"We have not received any reports from Bougainville," said a spokesman for the Papua New Guinea National Disaster Emergency Services in the capital, Port Moresby.
Magnitude 6 quakes are capable of causing severe damage and, if shallow enough, localised tsunamis, but are relatively common in Papua New Guinea, which lies on the so-called Pacific Ring of Fire, an area of intense seismic activity.