The earthquake occurred at 9.14am and was centred 45km north of Geraldine and 10km deep, GeoNet says.
More than 10,200 people reported feeling the shake on Geonet, the majority of which are in the South Island and some in the North Island.
A magnitude 3.4 aftershock caused weak shaking at 9.25am.
The 6.0 was described as a long, rumbling quake and didn’t cause any violent jolts.
It’s the first big shake to be felt in Canterbury for some time. The magnitude 6.3 quake on February 22, 2011, killed 185 people and caused widespread damage to Christchurch.
National Emergency Management Authority said there was no tsunami risk. No reports of damage have been made, but people were advised to access EQC.co.nz for insurance information.
'The house felt like it was sitting on top of a big pile of jelly'
Geraldine resident Fi McCafferty, who works for Geraldine News, said she was sitting at her desk in her villa when the earthquake struck.
"It was pretty shaky. It reminded me a lot of that first quake in Christchurch which we felt down here as well.
"The house felt like it was sitting on top of a big pile of jelly."
Nothing fell off the shelves at her place.
A worker at Barkers of Geraldine said the day was continuing as normal and there was no damage of which she was aware.
People have reported feeling the quake across Canterbury as well as Dunedin and Queenstown.
Andy Somerton, owner of the Fairlie Bakehouse, told the Herald he felt at least 30 seconds of shaking and considered diving under furniture.
”We were making that call in our mind, whether we needed to get down or not,” he said.
”We felt it and our first thought was ‘ah, please tell me that’s not Christchurch again”.
The shaking was “really strong”, the bakehouse owner said and he feared damage had been done to his store.
A quick inspection showed his shop was fine.
A Fire and Emergency New Zealand spokesman said he had spoken to Geraldine’s chief fire officer who said there were no reports of damage in the area at this point.
He was yet to speak to the other brigades in the area to confirm everything is OK.
A reporter in the Ashburton Courier office at the time of the quake said it was "a bit scary".
"It went on for some time. There may be a bit of hidden damage around the place," she said.
Timaru District Council has advised it is being cautious and closing the Farmers car park while engineers assess the structure after the big shake.
Timaru Mayor Nigel Bowen was sitting down when the earthquake struck.
”I sort of looked out the window for some major machinery but it had a good little rumble to it, only for about 10 seconds but yeah you certainly noticed it.”
He had a message for concerned residents.
“I think the key thing if you’re concerned about earthquakes and if there is to be more just go to the appropriate channels to find the information, go to the reputable news channels and find out what’s going on and Geonet and such.”
GNS duty seismologist John Ristau told RNZ the quake was centred almost exactly in the middle of the island but it's not clear yet which fault was triggered.
At this stage, the earthquake is believed to have happened at the junction of several fault lines, Ristau said.
But he did confirm it occurred 100km east of the Alpine Fault line and is not expected to have any impact on it.
There were likely to be plenty of aftershocks, some as strong as magnitude 4.
Earlier this year, Canterbury was rocked by quakes measuring 4.4 and 4.7. The quakes, in March and April, were the largest in the region in 2023 before today’s shake.
Other large quakes this year include a magnitude 5.6 north of French Pass on August 11, a 6.0 near Paraparumu that struck during Cyclone Gabrielle on February 15, and a 5.9 near Pōrangahau on April 26.
-With ODT online and NZ Herald
