A swarm of 100 aftershocks has continued to plague the North Island's East Cape since a severe earthquake struck early on Friday morning.

The quake - 7.1 in magnitude, 130km north-east of Te Araroa at a depth of 55km at 4.37am - was felt from Northland to Wellington in the North Island, and in the top of the South Island. Severe reports were felt in Gisborne and the Bay of Plenty.

The earthquake prompted a tsunami warning, which was rescinded after waves of 30 cm were measured off Gisborne's coast.

MORNING REPORT/RADIO NEW ZEALAND A GNS scientist Anna Keiser says many people would have felt the earthquake as would have been felt generated a long rolling motion.

The ground continues to shake the East Cape region, and it's likely to continue for some time, according to GNS.

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The Transport Agency says that is bringing with it a risk of rock-falls and slips on the roads, and it's urging drivers to be wary.

ONE News CCTV captured the moment Whakatane New World shelves started rocking.

The aftershocks were bringing increased risk at SH2 Waioeka Gorge, SH2 Maraenui, SH35 Motu Bluffs and SH35 Hawai to Te Kaha.

The region to the northeast of New Zealand where the Australia plate meets the Pacific plate has a history of generating large magnitude quakes and tsunami.

GeoNet received more than 5,000 felt reports in the 20 minutes after the 7.1 earthquake.

CIVIL DEFENCE Civil Defence issued this map showing the most likely North Island locations for tsunami waves.

GNS Science duty seismologist Caroline Holden said there was a flurry of aftershocks, including one M6.2 aftershock at 5.14am and a 6.0 at 8.06am. There have been more than 100 aftershocks since the initial 7.1 tremor.

FORESHOCK OR AFTERSHOCK?

Friday morning's big earthquake followed a 5.7 shake on Thursday in the same region, about 100km northeast of Te Araroa at a depth of 25km.

MORNING REPORT/RADIO NEW ZEALAND Head of national civil defence Sarah Stuart Black says tsunami alert will last for hours.

GeoNet says the aftershocks can continue for some time, but there was no way to tell whether Thursday's M5.7 shake was a "foreshock".

Holden said seismologists were working to confirm all the signals, which were "messy", and map the shocks.

"There's been a flurry of aftershocks. We have a team and we're monitoring the tsunami as well.

GEONET Map showing recent earthquakes in the New Zealand region. The red dots show severe quakes.

"We're in constant communication with civil defence."

CLOSE TO COAST, SMALL TSUNAMI

Holden said the tsunami generated by the quake was on the lower side but still created 30cm waves, and any waves hitting the east coast would not last long.

SUPPLIED Items fell from shelves, in this photo by Twitter user Mitch Kinny.

"Usually because it's quite close the wave won't last as long as getting an earthquake from [for example] Chile, but the whole North Island is prone to large quakes.

"Because of the proximity of the earthquake to the coast, we don't expect a very long tsunami signal, but every quake is unique. We're monitoring, it seems that most of the tsunami has passed."

GeoNet's tsunami expert panel team was monitoring the sequence and seismologists were analysing the felt reports.

MORNING REPORT/RADIO NEW ZEALAND Te Araroa local Aomihi Cook says locals are allowed to return home after Civil Defence tells them to head up the hill.

QUAKE-PRONE REGION

The United States Geological Survey said the east of the North Island has a history of large quakes along the plate boundary and seismic activity is particularly high in the Kermadec region.

Within a 250km radius of the M7.1 shake, there have been 28 earthquakes of M6 or larger during the 20th century.

A M7.1 occurred in the same region in 1995, about 45km to the southwest of Friday's shake, and was followed by a M6.5 aftershock five days later, the USGS says.

TSUNAMI WARNING LIFTED, BUT STRONG CURRENTS REMAIN

Strong currents are likely to continue for the next 24 hours, after Friday morning's jolt.

Civil Defence issued tsunami warnings for the East and North coasts of the North Island and for the upper South Island, but all tsunami warnings for coastal areas were lifted after 8am on Friday morning.

Civil Defence said based on available data the greatest tsunami threat had passed.

However strong currents and sea fluctuation levels were likely to continue through the morning.

The earthquake this morning prompted a large response from Civil Defence.

It issued warnings - beach and marine - for areas along the East Coast and North Coasts of the North Island and for the upper South Island. The upper South Island warnings were the first to be lifted.

Tsunami waves measuring 30 cm were picked up at Gisborne port and the gauge at East Cape.

Residents of coastal areas of Gisborne were initially warned to head to higher ground. Coastal residents were told to stay away from beaches, streams and estuaries and keep up to date with local emergency management.

ROCKFALL WARNING

The Transport Agency has issued a warning to drivers in eastern Bay of Plenty to watch for rock-falls and slips.

It says contractors are out checking the highway network, and that no damage or rock-falls have been reported yet.

However the continuing aftershocks are bringing an increased risk of the hazards in the following areas:

· SH2 Waioeka Gorge

· SH2 Waimana Gorge

· SH35 Maraenui

· SH35 Motu Bluffs.

· SH35 Hawai to Te Kaha

'ENOUGH TO MAKE ME STAND IN THE DOORWAY'

Gisborne District Councillor Pat Seymour was already awake in Whangara, near Gisborne, when the 4.38am earthquake struck.



"It was quite vigorous."

"It was enough to make me stand in the doorway- this was quite severe."

She had been up for an early flight and said it was dark when she had to drive down the coast to get to the airport and she watched the sea for signs of tsunami anxiously as she passed.

"The sea was flat and calm."

'I'M THE ONLY ONE LEFT IN TOWN'

Iain Fraser lives on Pohutu Rd, Te Araroa and was still at home.



"It was pretty severe shaking for a couple of minutes. Then a couple of very light tremors after that.



"I'm actually 1000 metres from the ocean but I'm up off sea level.

"I'm looking like the only one left in town at the moment."

'WE'RE AWARE OF TSUNAMI'



Tokomaru Bay resident Marlene Kipa said she was woken by shaking but stayed in bed.

The quake didn't feel particularly strong where she was - but the thought of the worst crossed her mind.

"That did cross my mind- the Christchurch earthquake- I wondered how they feel."

Her home is about 40 metres above sea level and she said the tiny township was used to the threat from the coast - its warning sirens had not gone off, but she had felt "three or four" aftershocks since.

"We're aware of tsunami. People on the East Coast are very wary of tsunami."

CIVIL DEFENCE ADVICE

In the event of a large earthquake, Civil Defence advises:



1. Expect aftershocks and remember to drop, cover and hold.



2. Look after yourself and get first aid if necessary. Help others if you can.



3. Assess your home or workplace for damage. If the building appears unsafe get everyone out. Use the stairs, not an elevator and when outside, watch out for fallen power lines or broken gas lines. Stay out of damaged areas.



4. Look for and extinguish small fires if it is safe to do so. Fire is a significant hazard following earthquakes.



5. Listen to the radio for updated emergency information and instructions.



6. Do not overload phone lines with non-emergency calls.



7. Help people who require special assistance – infants, elderly people, those without transportation, families who may need additional help, people with disabilities and the people who care for them.