The quake-weary city was woken this morning by shakes of 5.0 and 4.2 in magnitude -- both about 5km deep 20km southeast of the city - around 6.30am as water, waste and power are slowly being restored to full capacity since Monday.
GNS Science vulcanologist Gill Jolly said today before Monday's 6.3-magnitude tremor, the likelihood of a large quake -- post the deadly February 22 event -- was expected to be 25 percent.
However, Monday's quakes meant the chance of a magnitude 6.0 - 6.9 earthquake in Canterbury within 12 months had been recalculated at 30 percent.
Lines company restored power to about 1000 households overnight, leaving 2000 without power this morning. The company expected just 500 to be still offline tonight, company commercial manager Rob Jamieson told the broadcaster.
The affected areas would be in parts of Dallington and Bromley, as well as pockets around the city where there were cable faults.
Fifteen percent of households were without water last night and Christchurch City Council water and waste manager Mark Christison said it would be another 36 hours before the damage to the sewage system was fully assessed.
After the February 22 quake it was estimated it would take six months to fix the system completely, and that situation could be repeated, he said.
However, it was hoped people had kept their chemical toilets issued after the February quake and the council had 6000 chemical toilets stored.
Yesterday authorities warned people to wrap up warmly against the cold as efforts to restore power continued.
On a flying visit to inspect damage in Christchurch yesterday, Prime Minister John Key said he hoped announcements could be made soon on which parts of the city would have to be abandoned because of earthquake damage.
Thousands of people would have to abandon their homes, but Mr Key said authorities needed time to get the decisions right.
The Government had a "reasonably clear picture" about the areas of land that will not be rebuilt on but "it is extremely important to get it right", Mr Key said.
The Earthquake Commission also classified the quakes as a new event for insurance purposes with a closing date for claims of September 13.
Earthquake Recovery Minister Gerry Brownlee said there were at least 75 buildings in the central business district that had survived the February quake but now needed to be demolished urgently after yesterday's quakes.
Canterbury Earthquake recovery Authority chief executive Roger Sutton said this would have to be done as quickly as possible to allow access to the CBD.
