Tsunami threat in Vanuatu, New Caledonia largely passed

Earthquake, New Caledonia
It struck at a depth of only 10km. Photo credit: USGS

A tsunami threat has largely passed for New Caledonia and Vanuatu after a magnitude 7.0 earthquake rocked the two countries shortly before midday (NZ time).

Government authorities will monitor their coastlines to determine when it's safe for normal activities to continue, the Pacific Tsunami Warning Centre said.

Sea level fluctuations are expected to continue for the next few hours, with waves about 0.3 metres above and below usual levels. 

Waves up to one metre above the tidal level were expected to hit New Caledonia following the quake, while smaller waves were expected to hit Vanuatu.

Officials advised that the first wave to hit may not necessarily be the largest, and the time between wave crests could vary from five minutes to one hour.

United States Geological Survey says the quake struck at a depth of 10km.

Earthquake, Tsunami
The National Weather Service has urged authorities to take action. Photo credit: NWS

It comes after a magnitude 6.4 quake struck in the same area, 74km east of the Loyalty Islands in New Caledonia earlier on Monday.

Civil Defence said there was no tsunami threat to New Zealand.

Frequency of devastating earthquakes could triple next year - scientists

Researchers in the United States have warned we are likely to see a significant increase in the number of major earthquakes striking around the globe in 2018.

They say this small change in Earth's rotation speed could bring about increased seismic activity.

United States researchers Roger Bilham of the University of Colorado and Rebecca Bendick of the University of Montana found that when Earth's rotation decreased slightly, it was followed by periods of increased numbers of intense earthquakes.

They say this small change in Earth's rotation speed could bring about increased seismic activity.

"We have had it easy this year," Mr Bilham told The Guardian.

"So far we have only had about six severe earthquakes. We could easily have 20 a year starting in 2018."

NZN/ Newshub