It was a shaky first day on the job for Roger Sutton, chief executive of the Canterbury Earthquake Recovery Authority (Cera).

The former head of Canterbury power company Orion power started his five-year term today and at 1pm a 5.5 magnitude quake struck the city, the first of several large shakes this afternoon.

"It was all very strange really," Mr Sutton told Radio New Zealand.

"The building started shaking about 1 o'clock, it was swaying around.

"I hadn't actually been in a four-storey building before in a proper shake and it's quite an uncomfortable feeling."

By the time the biggest quake hit, a magnitude 6 at 2.20pm, Mr Sutton was in town where he had gone to meet city council and other civil defence officials and was standing outside the art gallery.

"That was very frightening," he said.

"The ground went up and down, it swayed, the buildings around us were moving and they continued to sway even after the shaking had happened.

"I guess we do know that eventually it's going to stop but in the meantime it's very frustrating for everybody."

Mr Sutton said that the civil defence response was "like a well-oiled machine".

"I can imagine there will be people who are feeling 'gee we're just back to square one', but I think the power will be back on reasonably quickly within 24 hours, the water's out in some areas but hopefully that can be fixed reasonably fast."

Mr Sutton said life went on.

"We all live here and we have to make the best of things and we have to bring the city back to what it was."

He said it had been difficult to move round the city to see how much liquefaction had happened, but it was likely there were areas where it would be severe.

He guessed the only positive thing was that there were a lot of portaloos in the city.

"We're not going to have a shortage of portaloos if we do have significant sewerage issues for a period," Mr Sutton said.

Earthquake Recovery Minister Gerry Brownlee was on his way to the city and Mr Sutton wanted to meet him and share the information he had gathered.

He said as a result of today's quakes it was likely demolitions in the CBD would need to be speeded up because there were buildings now that were seriously weakened that weren't actually damaged previously.

"We need to bring them down so we can access other areas. If anything it may actually speed some of the aspects of the recovery up rather than slow them down," Mr Sutton said.