WELLINGTON (Reuters) - This week's earthquakes in Christchurch, New Zealand's second biggest city, confirm parts of the quake-prone city will have to be abandoned, but did not substantially add to damage bill from a series of major tremors since last September.
The series of quakes, the most powerful one upgraded to magnitude 6.3 from an initial measurement of 6, sent boulders tumbling down hillsides and destroyed buildings already weakened in previous quakes, as the city struggles to recover from a February 22 shake which killed 181 people.
"The damage that occurred yesterday has simply exacerbated the damage that occurred in the two previous events in the same places as before so I don't think it's going to hold us up or put us back," Earthquake Recovery Minister Gerry Brownlee told Radio New Zealand.
An elderly man had died at a rest home in the city as a result of this week's quakes, local media reported on Tuesday, although no other details were immediately available.
Brownlee said the most recent tremors, which injured 46 people, confirm that parts of the eastern side of Christchurch needed to be abandoned and should hasten the decision-making process.
However the fresh round of shakes had done little to dent the rebuilding plan, and would not substantially add to the overall NZ$15 billion ($12.2 billion) damage bill, Brownlee said.
Parts of eastern Christchurch suffered further liquefaction, where water pushed up from under the ground by the force of the quake turns the ground into liquid. Other parts of the city could be at risk of liquefaction in future earthquakes, and will likewise need to be abandoned.
New Zealand's GNS Institute, which has warned the latest series of tremors could produce another spate of powerful aftershocks in the weeks to come, has reported 37 earthquakes of magnitude 3.2 or greater in the Christchurch area in the past 24 hours.
Early on Tuesday about 15,000 houses remained without power, and many schools and businesses were shut as residents were asked to stay at home so essential infrastructure could be repaired.
Christchurch has experienced a number of strong earthquakes since a magnitude 7.1 quake struck the city on Sept 4 last year.
Parts of the city center have been closed since the Feb 22 quake, and many of the buildings in the area sustained further damage or collapsed after the latest shakes.
The New Zealand dollar lost as much as a cent in the aftermath of the quakes on Monday, as markets trimmed expectations the central bank would raise rates this year.
The Reserve Bank of New Zealand cut rates after the February tremor to a record-equaling low of 2.50 percent. But signs of recovery and an upbeat assessment from the bank at its review last week had led markets to price in rate rises from December.
"It is not difficult to imagine that this new damage may delay the reconstruction effort in the city and thus, all else equal, the timing of when the RBNZ needs to begin withdrawing monetary stimulus," said Deutsche Bank chief economist Darren Gibbs.
(Reporting by Adrian Bathgate; Editing by Balazs Koranyi)