NZ's South Island shaken by a spate of quakes
A spate of strong earthquakes have struck the central South Island this morning.
Four quakes measuring between 6.4 and 4.1 in magnitude hit the Methven and Arthur's Pass area between 6.48am and 6.59am.
The first tremor, measuring 6.4, struck 35km north of Methven at 6.48am, GNS Science reported.
The tremor, which was 11km deep, was classified as severe.
A southern police communications spokesman said they had not received any reports of damage.
Four minutes later at 6.52am, a second quake measuring 4.1 in magnitude rocked the region.
It was centred 30km west of Arthur's Pass and was 5km deep.
GNS classified the quake as strong.
At 6.58 a third quake, measuring 4.1 hit the same spot, GNS said.
It was 5km deep.
Then, a minute later at 6.59am, another strong quake hit the same location, measuring 4.2 in magnitude. It was also shallow, centred 5km deep.
St John spokesman Ian Henderson said there had not been any calls relating to this morning's earthquakes and there had not had any increase in calls because of them.
There were also no reports of injuries, he said.
Seismologist: Another big aftershock possible
GNS seismologist John Ristau told Radio New Zealand the quakes were widely felt, with so far nearly 2000 people reporting feeling the tremors.
The initial 6.4 quake generated the aftershocks, he said.
"With an earthquake of this size it wouldn't be unexpected that an aftershock above magnitude 5 [would hit] - so it's quite possible that we could see an aftershock of that size at some point."
The tremors were felt in Canterbury and the West Coast, he said.
Landslides could also have been triggered from the quakes.
"We'll probably end up sending people down there to have a look."
Residents describe early morning shakes
New Zealand Herald readers have been sending in their experiences of the earthquakes.
Tony Foote said the quakes were "disturbing".
"It rolled on a bit, quite heavily and I felt a bit sea sick as my chair moved about. A bit like being on a rising and falling wave in a small boat.
"There was a worry it might be something bigger on the way as an ornament I hung to see when quakes were happening swung 100mm side to side for several minutes, and the water in my cats bowl moved up and down 20mm or so."
Graham Walker said he felt the quakes in Timaru.
"As I was eating breakfast house was rolling around for about 10-15 seconds."
Brian Feary tweeted: "Big earthquake here in Arthur's pass! My dog ran in from outside and jumped on bed... No damage so far #eqnz".
The Queen of Cobden wrote: "That #eqnz just felt like the house was at sea (in Christchurch)".