By Tom Westbrook
SYDNEY (Reuters) - A powerful undersea earthquake with a magnitude of 7.1 struck on Wednesday near New Caledonia in the South Pacific, creating small tsunami waves, but there were no reports of damage, regional officials said.
The quake hit at a shallow depth of 27 km (17 miles) about 372 km (230 miles) east of Noumea, the capital, the U.S. Geological Survey said, estimating an initial magnitude of 7.
The Pacific Tsunami Warning Centre (PTWC) said the tsunami threat had largely passed, although coming hours might see some movements in sea levels.
The biggest waves, just over 1 foot (0.3 m) high, hit the main island of New Caledonia without consequence, Olivier Ciry, the civil defence spokesman of the French Pacific territory, said by telephone from Noumea.
"We felt it and they felt it more strongly on the Loyalty Islands," he said. "There was some movement of the sea but no damage to buildings, no injuries to people and it's over now."
Gauges at Lenakel, a town in Vanuatu, about 300 km (186 miles) from the epicentre, logged waves 27 cm (10 inches) high, the PTWC said.
It had warned against the risk of waves between 30 cm (1 ft) and 1 metre (40 inches) higher than tide levels striking islands around the Pacific and as far away as Australia, New Zealand and Papua New Guinea. But no waves of that size were recorded.
"We're still monitoring it and on standby but there's nothing on the tide gauges for the time being," Laisenia Rawace, an official in Fiji's seismology monitoring department, said by telephone from Suva.
Wednesday's quake in the area situated on the earthquake-prone Pacific Rim of Fire came 10 days after a massive, but very deep, quake rocked the sea floor near Fiji and 11 months after big quakes hit near the Loyalty Islands, also without damage.
(Reporting by Michael Perry and Tom Westbrook; Editing by Paul Tait and Clarence Fernandez)