There is no tsunami threat to New Zealand after a magnitude 7 earthquake struck in the Kermadec Islands region in the Pacific Ocean, Civil Defence says.
The organisation issued a tsunami warning at 11.37am Sunday, following the quake just after 11am.
However, an all clear was issued eight minutes later.
“Based on current information, the initial assessment is that the earthquake is unlikely to have caused a tsunami that will affect New Zealand,” it said.
A Civil Defence spokesman said strong currents were possible, but “we’re not expecting anything that means people need to stay away from beaches or off boats”.
The emergency mobile alert system was not used to alert people to the original tsunami warning as “the threshold for using that is very high”, he said.
That original warning was for strong and hazardous currents and unpredictable surges which could threaten beaches, harbours and estuaries.
However, flooding of land areas, near the shore, had not been expected.
“A land inundation threat would always result in an emergency mobile alert being issued,” the spokesman said.
Some people received text alerts from their local Civil Defence groups, such as Bay of Plenty, he said.
“They have their own text alert systems … not all Civil Defence groups have the same local information systems.”
He said the reason for the quick retraction of the tsunami warning was information gathered from tidal gauges at Raoul Island, the largest of the Kermadec Islands.
“We were able to pick up that there were no significant tsunami waves. We can’t wait for that before issuing a tsunami warning because the Kermadecs are so close to New Zealand, but when we got that information it was very good news.”
The Pacific Tsunami Warning Center, based in Hawaii, said a tsunami threat existed for parts of the Pacific located closer to the earthquake.
The Kermadec Islands are uninhabited bar a government station on Raoul Island.
According to Civil Defence, the quake was 10km deep. It was originally reported as magnitude 7.4, but later downgraded to 7.
The Kermadec Islands are about 800-1000km northeast of the North Island. They can only be accessed with a permit from Customs and the Department of Conservation (DOC).
They are uninhabited apart from Raoul Island Station, where there is a meteorological station and a hostel for DOC workers and volunteers.
DOC said all seven of its staff based on the island had been accounted for and were safe.
“No other contractors or visitors were on the island when the quake struck.”
A spokeswoman said staff would look into whether there had been any damage to the island on Sunday.
Earthquakes have frequently struck the Kermadecs, including a 7.4 magnitude quake in 2006 and a 7.6 in 2007.
In 2011, two quakes, measuring 7.6 and 7.4, struck three months apart.