'We definitely felt it': 'Severe' magnitude 5.5 quake shakes top of South Island

A severe magnitude 5.5 quake caught many by surprise as it shook central New Zealand on Sunday afternoon.

The quake occurred at about 4.15pm and was initially recorded as 'strong' by GeoNet.

As of 4.30pm, GeoNet had revised its depth to 12km and the epicentre to 10km east of Seddon.

GeoNet revised the intensity to "severe", with the quake's severity felt as far north as Auckland.

Marlborough District Council mayor John Leggett told AAP he was at the Picton Christmas parade when the quake occurred.

"We were down on the foreshore and we definitely felt it. It was pretty significant," he said.

He's been seeking information about any damage but hasn't received any reports yet.

Wellington City Council spokesman Richard McLean says "emergency controllers have been talking to each other" but there are no reports of damage in the capital.

Council staff are checking with contractors demolishing a high-rise building in Molesworth Street, damaged in previous quakes, to see if there are any issues with it.

GNS Science duty seismologist Bill Fry told NZ Newswire the quake was part of a sequence of aftershocks following the 7.8 quake on November 14.

"It's in an a location that we've seen a lot of other earthquakes. It was quite large," he said.

He added that at the epicentre of the quake the ground shaking would have been severe.

The aftershock also triggered a relatively moderate quake in the Hawke's Bay region at about the same time, Fry said.

The Hawke's Bay quake, centred 25km south of Hastings, was initially recorded as a 4.8 but was downgraded to a 3.

The Fire Service says there have been no damage reports yet from the aftershocks.

Speaking to NZME, the owner of SuperValue in Seddon, Kevin Kamat said the shaking lasted for about five seconds.

"It was quite strong. We had about 12 customers in the store and everyone made a beeline for the door."

Over 7,000 people reported feeling it on the GeoNet website

Thousands of aftershocks have been recorded since the 7.8 quake three weeks ago, which isolated the South Island coastal settlement of Kaikoura and altered the landscapes around it.

Plenty of people around the country have taken to social media following Sunday's shakes, with one man likening the quake to Ray Columbus' funeral.

"Lasted about 30 seconds and felt like Ray Columbus's funeral- a heap of rock and roll. Parliament creaked and flexed, people dived under desks," Michael Rhodes wrote in a post to Facebook.

"I enjoyed it, very rolling and uncertain. Not a sudden jolt."

On Twitter, many Tweets rolled in recounting the tremor:

More to come.

– With NZN