'All I can hear is alarms' - 4.9 quake rocks Christchurch

Smoke rises from the collapsed CTV Building on February 22. Photo / Mark Mitchell

A shallow magnitude 4.9 earthquake has rocked Christchurch early this morning.

The quake struck at 3.29am, and was centred 10km east of Lyttelton, off the end of Godley Head, at a depth of 6km.

GNS Science said the quake could have caused minor damage, and had reports it was felt as far north as Hanmer Springs and as south as far as Timaru. One person in Bromley reported the quake as "damaging", while another 14 told GNS Science it was "slightly damaging".

A Fire Service spokesman said there had been no reports of damage and Orion said all power had remained connected following the quake.

Christchurch residents turned to Twitter to share their experiences.

CTV presenter Kineta Knight was one of many who had been shaken awake.

"That must have been a big one. All I can hear is alarms!! Long and rumbly."

Many said it felt bigger than a 4.9.

"I demand a recount! That's the first time a 4.9 has knocked something off my shelves!" Gavin Treadgold wrote.

Newstalk ZB reporter Jo Scott said the quake shook her family awake, and went on for quite awhile.

"It's just been unbelievable that in two days time it's going to be the first anniversary of September 4, and we are still getting earthquakes a year later," she says.

Since the September 4, there have been at least 8,300 earthquakes in the Canterbury region, with more than 300 larger than magnitude 4.

Today's quake is the third magnitude 4 or larger aftershock, with magnitude 4 and 4.7 quakes striking on different fault lines on Wednesday afternoon.

According to GNS Science's last forecasts, updated last month, there is a 26 per cent chance of a quake magnitude 5 to 5.4 occurring between August 15 and September 14.

Within that same period there is a 6 per cent chance of a magnitude 5.5 to 5.9, a 3 per cent chance of a quake 6 to 6.4, and less than one per cent chance of a magnitude 6.5 and higher.

In the next year, there is an 82 per cent chance of a quake measuring between 5 and 5.4, a 39 per cent chance of a quake 5.5 to 5.9, a 10 per cent chance of a quake between 6 and 6.4, a 5 per cent chance of a magnitude 6.5 to 6.9 and a 2 per cent chance of a jolt measuring 7 to 7.9.

- with Newstalk ZB