Tsunami watch for NZ, Fiji after massive undersea quake

A tsunami warning was issued after a massive undersea earthquake measuring 7.7 on the Richter scale struck a region between Australia and Fiji and north of New Zealand, according to authorities.

"Hazardous tsunami waves are forecast for some coasts. Tsunami waves reaching 0.3 to 1 metres above the tide level are possible for some coasts of Fiji, New Zealand and Vanuatu," the US-based Pacific Tsunami Warning Center said in a statement following the quake on Wednesday night.

The magnitude of the quake was previously measured at 7.9 and 7.5 by the US Geological Survey (USGS), but was later revised to 7.7.

The epicentre, with a depth of 10 km, was initially determined to be at 23.1 degrees south latitude and 171.5 degrees east longitude.

The initial temblor was followed by at least three other earthquakes in the South Pacific region with magnitudes ranging from 5.7 to 6.1 in a span of over an hour, reports Sky News.

In an official advisory issued on Wednesday night, the New Zealand Civil Defence National Emergency Management Agency said: "We have issued a national advisory: Tsunami activity following the magnitude 7.7 earthquake near southeast of Loyalty Island. We expect New Zealand coastal areas to experience strong and unusual currents and unpredictable surges at the shore."