Christchurch still on edge after earthquake

Regular aftershocks since it was convulsed by worst earthquake in 80 years have made living in Christchurch a nerve-racking experience.

Residents stand outside a wrecked building after the earthquake in Christchurch on September 4.

Christchurch, New Zealand // Although more than 14,000 earthquakes strike New Zealand each year, jittery residents of the second-largest city on the "Shakey Isles" wonder how much more they can endure.

About 2,000 aftershocks - an average of more than 40 each day - have been recorded in Christchurch since September 4, when seismic convulsions reverberated through one of New Zealand's most heavily populated regions, leaving roads severely cracked, railway lines buckled and many buildings in tatters.

Yesterday, a magnitude 5.0 earthquake shook the city, six weeks after the South Pacific country's worst earthquake in 80 years caused widespread damage.

The massive shockwave measured 7.1 on the Richter scale, comparable to the earthquake in Haiti that claimed more than 200,000 lives in January.

Remarkably there were no fatalities in Christchurch, and although civic leaders have been quick to acknowledge their good fortune, the city's confidence, as well as its infrastructure, has suffered badly.

The mayor, Bob Parker, said the epicentre of this week's earthquake was 10km south-west of the city and while it caused only minor damage, it has again shredded the nerves of residents.

"It really shook people up and the psychological impact for a city that has been subjected to a fairly traumatic period can't be underestimated.

"We'd rather we didn't get these reminders of the event of early September."

The vast majority of the aftershocks have been minor and many have gone unnoticed but Siobhan Grimshaw, 43, an occupational therapist in Christchurch, said there have been up to 30 major shudders in the last six weeks.

"One shook our house much more than the 7.1 did," said Mrs Grimshaw.

"It caused lots of cracks and the whole building shook violently again and again. I ran out of the house terrified and didn't want to go back in.

"I felt there was a clamp around my heart and I was in a permanent state of fear for 24 hours," she said from her home overlooking the ocean.

Flying into Christchurch there are few visible signs of the damage inflicted on this lush corner of New Zealand's South Island by rampant subterranean forces, but the repair bill is expected to top NZ$6 billion (Dh16.5bn) and restoration work is likely to take years to complete.

So far, emergency authorities have received 100,000 claims for financial assistance from homeowners and businesses.

Mr Parker said that the reconstruction effort would be immense. "It is a massive task. It is important to not overstate the damage to the city. More than 95 per cent of Christchurch is fine, but there are some small parts of the fabric of the city that were severely hit," he said.

Already many unstable buildings have been torn down and the construction industry in particular can look forward to busy times ahead.

"It will result in a bit of a boom for the city in the coming years, so there is an upside to a devastating event," Mr Parker added.

Since 1840, New Zealand has recorded about 20 earthquakes that have matched the potency of last month's earthquake in Christchurch.

Euan Smith, a professor of geography at Victoria University of Wellington, said although destructive, such occurrences were rare. "This is the first earthquake that we have had in New Zealand of magnitude 7 or greater close to a population centre since 1931.

"Compared to what happened in Hawkes Bay [in 1931] where some 250 people were killed in a rather bigger earthquake, we certainly got off very lightly in terms of casualties," Mr Smith said.

"Since then we have had a succession of building codes, which have improved the quality of the built environment."

Luck and sound planning helped Christchurch avoid any loss of life when the Earth shook for 40 terrifying seconds in early September. It was 4.30am and most people were asleep, many in timber homes built to bend but not break under such pressure.

"The building codes have served us very well. However, there is always something more that can be learned," added Mr Smith, who said the September 4 quake would give scientists an unprecedented insight into why such seismic disturbances occur.

"From that data we will learn lessons about how to better design domestic and commercial property to resist earthquakes of this kind."

For now, the challenge is to rebuild and regroup. So-called "survivors' parties" have been held across Christchurch as the community bands together to offer support and solidarity as the ground continues to growl beneath the surface.

For Kay Hood, a breeder of thoroughbred racehorses and Siamese cats, who lives on the outskirts of Christchurch, the memories of the earthquake remain vivid.

"My husband likens it to trolls underneath the concrete floor trying to break through.

"The earthquake rumbles and sounds like a jet plane coming," Mrs Hood explained. "We haven't lost our house and we haven't lost our lives but we've just about lost our sanity because it is very difficult to sleep. My husband has taken it fairly badly."

New Zealand experiences more than 14,000 earthquakes each year and lies on the notorious Pacific Ring of Fire, a vast area of unpredictable seismic activity.