A 6.5 magnitude earthquake west of Taupo this afternoon was felt widely through the North and South islands, but no damage has been reported.
The quake, which struck at 3.36pm, was centred 150km deep, 30km west of Taupo.
The deep rolling earthquake was felt throughout the lower North Island and as far south as Christchurch.
GNS volcanologist Brad Scott said although the earthquake was centred near Taupo it would have been felt more strongly along the East Coast, particularly the Napier through Wellington region, because of its depth.
Today's earthquake was fairly typical movement, he told Radio New Zealand.
"We would typically have maybe two or three events around maybe 5.5 and 6 (magnitude) at about 150-200km depth a year under the North Island. It's slightly larger than average but it's kind of what we really expect."
It would generate some aftershocks "but at that depth and being smaller than the main shock they are very unlikely to be noticed", he said.
Bookshelves swayed but no books were dislodged at Wellington Central Library, while John Key's press secretary, Lesley Hamilton, said the quake was felt strongly on the ninth floor of the Beehive.
Briar Charmley, private secretary for the Attorney-General on the 19th floor of Bowen House in downtown Wellington, said the building swayed more than in any previous earthquake she had felt in her 12 months in the office.
"It was relatively short but nonetheless quite violent compared to all the other earthquakes I've felt in this building.
"It felt bigger than the February 22 quake in Christchurch, which we also felt here, so my immediate thought was, 'gosh, I really hope that's not a Christchurch earthquake, because if so it must be huge'."
Police Central Communications said it had not received any reports of damage, and nor had Taupo Civil Defence.
A quake at that depth should have no effect on property, Taupo emergency manager Phil Parker said.
The quake was felt as far away as the Hawkes Bay and Christchurch and Geonet data centre spokeswoman Jennifer Coppola said the quake was the largest to strike near Taupo for a decade.
However, earthquakes in the area were common and this was not a sign of increased volcanic activity around Lake Taupo, she said.
"Volcanoes are not related to earthquakes. They have quite a different signal.
"I wouldn't say this is unusual. It's an active zone. Just the magnitude is the something out of the ordinary."
The depth of the earthquake meant it was felt over a wider area than a shallow quake like the 6.3 February 22 aftershock in Christchurch, Ms Coppola said.
Residents throughout the North and South Islands took to Twitter to report the quake.
RitchOC said: "Earthquake!!! That was a biggie...6.5! Ran out house here in Kapiti. Still shaking... Me that is...There goes tonight's sleep."
Sam Rye said: "Fair sized earthquake in Wellington #eqnz - shaking building!"
Others compared the quake given to the 2.9 magnitude shock that struck Auckland on Friday.
"Aucklanders make a big deal over a 2.9 that felt like a gust of wind all over the news. Wellingtonians brush off a 6.5," Keegan Check said.
One Twitter user blamed America's July 4 celebrations: ``This is what happens when you overdo the 4th of July fireworks, America!''
- HERALD ONLINE