People across the South Pacific - including in New Caledonia, Fiji, Vanuatu and New Zealand - were all told to avoid coastal areas due to the risk of tsunami waves following the 7.7 magnitude earthquake on Friday southeast of the Loyalty Islands in the French territory of New Caledonia.

The Pacific Tsunami Warning Center said waves less than half a metre were measured off Lenakel, a port town in the island nation of Vanuatu. Smaller waves were measured elsewhere off Vanuatu and off New Caledonia.

But the Pacific Tsunami Warning Center (PTWC) said the tsunami threat had largely passed on Friday afternoon.

Earlier it had warned about the possibility of waves ranging up to one metre above the tide level across 26 locations in the South Pacific.

Australia's Bureau of Meteorology had issued a tsunami threat for Lord Howe Island, 700km southeast of Brisbane, warning the roughly 450 inhabitants to leave the water's edge due to waves and strong currents.

This was later downgraded to a marine warning.

"We haven't moved to higher ground and we're probably not going to," said Damien Ball of the Thompsons General Store on Lord Howe Islands earlier. "We've been through this numerous times before and nothing ever comes of it."

Vanuatu retracted a warning to seek higher ground and said a destructive tsunami is no longer expected, according to the Vanuatu Meteorology & Geo-Hazards Department website.

Geoscience Australia said the quake hit at a depth of 31km, while the United States Geological Survey (USGS) had it at 38km.

Australian Associated Press