A 4.5 magnitude quake has rocked Christchurch this morning. Image / Geonet
A shallow quake that rocked Christchurch this morning has been upgraded to a stronger magnitude 4.6.
Geonet says the moderate tremor struck 20km southwest of the garden city at 7.26am.
It was initially recorded as a 4.5 quake but revised upwards to 4.6 on review.
It was measured at a depth of 9km.
Around 7500 people recorded feeling the quake with more than 4100 saying it was a light shake.
Geonet said the quake was felt across Canterbury.
"That was a decent shake for Canterbury this morning," it posted.
"It was felt across Canterbury and we have received over 7400 felt reports."
People living in the region described it as an "almighty jolt" and an unwelcome start to the day that sent pulses racing.
Others said it was scary and seemed to be stronger than the registered magnitude 4.5.
"Just down the road from us here in Rolleston. Felt bigger than that. Got the heart racing early in the morning," posted Rachel Briggs on Facebook.
Haley Cook said it was felt just out of Rakaia.
"Was just one almighty jolt," she posted.
Lesley Murdoch was in Christchurch at the NZME building when the quake struck.
She said they got a bit of a warning and could hear something coming before it struck.
"Boy when it hit it was a bit of a shock and the monitors went, they really shook, we had to hold on to them. What a start for a Friday morning, not good."
Rolleston cafe worker Jordy Macdonald said she knew it was a big one as soon she saw a staircase move.
She said now every single customer they have had come in had said the quake was a big one.
"I'm from Wellington and its the first one ive felt since moving here."
A man known to the victim has been charged with assault.