Heavy swells 'unlikely' following early morning East Coast earth quake

The magnitude 7.4 shake was felt by thousands around the country. Photo / Supplied

Civil Defence Hawke's Bay says earlier warnings of "unusual swells" on our coastline following this morning's earthquake would be "highly unlikely".

Many Hawke's Bay residents were shaken awake last night as a 7.4 magnitude earthquake off the East Coast was widely felt by thousands around the country.

More than 8900 people - including residents in Napier, Hastings, Gisborne, Bay of Plenty and Wellington - registered feeling the quake at 12.50am.

Despite initial fears of a tsunami after the quake occurred - and social media reports that some residents had moved to higher ground in some areas - officials later said there was no threat.

Civil Defence Hawke's Bay also does a regional assessment.

These concluded that there was no tsunami risk to the country and region.

The earthquake, which was 710km north-east of Gisborne and 33km deep, has been listed as 'weak' by GeoNet.

"Our Modified Mercalli intensity scale gives the impact of an earthquake on people living on the earth's surface, instead of magnitude which is the energy released during an earthquake, and so can be more useful as an indicator of the earthquake's significance to the community," Sara Horne from GeoNet said.

On the intensity scale, a weak earthquake will be felt indoors as a light vibration and hanging objects may swing slightly.

The felt reports are used to map how widely and strongly an earthquake was felt.

"There will often be felt reports above what the earthquake is classified, as how a person perceives shaking can vary, but the felt report maps give us a rough idea on where and how an earthquake was felt," she said.

"If people feel long and strong [earthquakes] they should self-evacuate and listen to the radio for updates," Civil Defence Hawke's Bay group controller Ian Macdonald said.

"If you're ever in doubt, do what you think is right."

Civil Defence has said New Zealand coastal areas may experience strong and unusual currents and unpredictable surges at the shore.

Macdonald said this was a national warning which was issued to inform people, but it was "highly unlikely" that there would be much affect in Hawke's Bay.

However, residents should be aware of the warning and be careful, particularly those working near the water, he said.

Residents took to social media to share their quake experiences.

"I think the whole of HB felt it! Can't believe they're still classing it as weak though, felt anything but," one person said.

"I felt it up here at Pukeora Hill, Waipukurau, didn't hear it coming, it was wave-like, rather than jolty, lasted less than a minute," another said.

Some also felt it was stronger than its 'weak' classification, while others across the region said they didn't feel a thing.