Tsunami warnings correct - Minister

Map showing the site of this morning's earthquake in the Kermadecs. Photo / supplied

The Government is telling the public that they should listen to Civil Defence for disaster warnings - rather than any other body.

The Pacific Warning Centre based in Hawaii called off its tsunami warning after the 7.6 earthquake in the Kermadecs before Civil Defence here did.

Civil Defence Minister Craig Foss says the chain of command here is clear.

"The official advisory body is New Zealand Civil Defence and the messages they sent erring on the side of caution was correct as normal."

The Pacific Tsunami Warning Centre is to drop the word "warning" from its bulletins because it's too alarmist and confusing.

Dr Suart Weinstein from the Centre told Radio New Zealand said the warning has become too confused, and it undermines the warnings from national authorities.

"Their decisions are in effect short circuited because the public has access to our bulletins.

"It is a problem."

Dr Weinstein says the Centre may assign threat levels instead, but discussions are still taking place as to what shape those bulletins will take.

Meanwhile scientists say New Zealand was never in any danger of a large tsunami hitting its shores, as the seismic energy from a huge earthquake north of the country was directed away from here.

Tsunami scientist William Power of GNS Science said the direction of the fault rupture was north-south and most of the tsunami energy was radiated to the east and west, rather than south towards New Zealand.

The largest waves were also sent in an east and west direction, rather than south, Dr Power said.

The biggest of those waves reached 1.9m at Raoul Island, at the top of the Kermadecs -- about a metre higher than normal.

Small tsunamis, not much larger than normal waves, were subsequently observed on gauges at Great Barrier Island and East Cape.

Scientists realised the tsunami threat was small when a wave reached a tsunami measuring gauge anchored to the floor of the Pacific Ocean, 40 minutes after the quake occurred.

"The characteristics of the wave as measured at the (gauge) gave us a degree of confidence that only a small tsunami had been generated and New Zealand was not in its main path," Dr Power said.

It was appropriate to issue the initial tsunami warning and then downgrade it as more information came to hand, he said.

Waikato Regional Council's navigation safety team said the quake could lead to strong currents and unusual water patterns over the next few days, particularly on the east coast.

Meanwhile, a few residents in Gisborne area headed to higher ground and vantage points such as Kaiti Hill, some armed with binoculars after the quake alert.

They included a group of Chilean people who expressed fears for their lives.

But the crowds on hilltops did nor rival the numbers seen after previous alerts, which almost caused traffic gridlocks on hilltop roads.

In Auckland and other parts of the east coast of the North Island, authorities said there was an increased swell in coastal areas but little to cause concern.

On the east coast of Northland there were significant swells about 10am.

Dive Tutukaka, which is based in the Tutukaka Harbour just north of Whangarei, cancelled three or four dive charters out to the Poor Knights Islands today because of the swells and a gale warning for later today and tomorrow.

Dive Tutukaka's Kate Malcolm said the water was calm and flat but there was a rise and fall of about half a metre in the harbour and they were expecting that to continue.

- NZPA