It struck at 9:07 p.m. (7:07 p.m. AEST) and was located 30 km northeast of the French pass at the top of the South Island, at a depth of 51 km, GNS Science said.
More than 44,000 people reported feeling the earthquake – residents from across New Zealand, including Christchurch, Motueka, Wairarapa, Raglan, New Plymouth and South Auckland.
About 44 people in the country rated the shaking as extreme, including reports from Auckland and Christchurch.
Wellington man Andrew Chen said his Air New Zealand flight from Auckland to Wellington was unable to land safely shortly after the quake.
“The captain said they had to check the runway for damage before we could land,” Chen said.
After cruising around Wellington Airport for about half an hour, the plane was due to land in Christchurch when it ran low on fuel.
Chen said the flight was refueled and left for Wellington after 30 minutes in Christchurch.
“We could have reached Sydney in the time it took to reach Wellington, but I understand they cannot compromise on security,” Chen said.
Wellington Airport has confirmed that one flight has been affected.
John Robins in Levin said his house creaked from “moderately slow shaking”, while Richmond’s John Emanuel near Nelson described the quake as a “sharp, single jolt”.
Alison Tuck in Waikato said she mistook a “gentle rolling motion” for a dizzying spell and was pleased to find that she wasn’t imagining things when she read about the earthquake on stuff.
David Whyte in Wellington said he was surprised to find that his wife in another room did not feel what he described as a “sharp, sideways shift from east to west”.
“The cat didn’t move either. I find that odd because this tremor was fast and sharp. I can’t believe she didn’t feel the tremor,” Whyte said.
A Foxton Beach resident said they felt a “very strong” jolt, “long rolling”.
Alison Armstrong, of Nelson, said the “long, strong” earthquake gave her quite a shock.
“It’s been a while since the Kaikōura, Seddon earthquakes. So [it was] quite a wake-up call,” she said.
Philippa Smith was in a hospital in Wellington recovering from a joint replacement when the earthquake shook her room.
“I couldn’t ‘drop, cover and hold’ tethered to drops and bags,” she said.
Smith said she felt “shocked” by the event but was confident she was safe and “in a good place in the hospital”.
GNS Science seismologist John Ristau said many factors could influence how an earthquake was felt across the country.
Ristau said the earthquake’s 51 km depth meant it would likely be widely felt, but the seismic energy radiating from the epicenter was uneven.
The nature of the soil and architectural style can also affect the amount of shaking a person felt.
Melbourne earthquake aftermath
“If you’re on soft ground, the shaking will be much greater than on rock. And wood-frame houses will react very differently to shaking than brick or concrete,” Ristau said.
In 2020, researchers at the Victoria University of Wellington mapped the density of the rock base and sediment beneath Wellington City after the 2016 Kaikōura earthquake severely damaged some buildings, while other areas appeared more stable.
During the study, master’s student of geophysics Alistair Stronach said the sediment above the city’s bedrock had an effect akin to “jelly in a bowl.”
“The 2016 earthquake had particularly severe shaking in Thorndon and around the waterfront, mainly because of the depth of the sediment there. The deeper it is, the worse the shaking is,” Stronach said.
On Friday, there were no reports on the GeoNet website of significant aftershocks.