The quake's epicentre was 136 km (84 miles) southwest of Isangel in Vanuatu and 147 km north-east of Tadine, in the Loyalty Islands, New Caledonia, the USGS said in a bulletin. The quake was 26 km deep.
"Based on all of the local analytical data, a tsunami is not expected within Vanuatu," an official for the Vanuatu Meteorological Services told Reuters by telephone from the capital, Port Vila.
A receptionist at a hotel in Ouvea in the Loyalty Islands said there was no immediate sign of damage.
"It was not a particularly strong tremor but we definitely felt it. There was no breakage, no damage," the receptionist at the Hotel Paradis d'Ouvea said.
View Larger Map