A magnitude—5.1 aftershock hammered New Zealand’s earthquake—hit city of Christchurch on Wednesday morning, freshly damaging buildings, sparking evacuations and prompting the extension of a state of emergency for another week.
The latest quake, just four miles (6.4 kilometers) below the surface and centered six miles (10 kilometers) southeast of the city, was felt by residents as the strongest aftershock in Christchurch since Saturday’s 7.1 magnitude earthquake wrecked hundreds of buildings. Nobody was reported injured by the latest temblor.
“My guts is just churning up here. When will this thing end? It is like living in a maelstrom,” Christchurch Mayor Bob Parker said as workers streamed from the city’s emergency headquarters.
“We have got staff in tears, we have got fire engines going through the middle of the city, power is out and a lot of people are very, very churned up by that,” he told the NewstalkZB radio station. “It was a devastatingly, vicious sharp blow to the city.”
Initial reports from geological agency GNS Science that Wednesday morning’s temblor was magnitude—6.1 were quickly corrected downward.
Officials closed the city’s main road tunnel for inspection due to concerns that the aftershock may have caused cracking to the tunnel and retaining walls leading to it, New Zealand Transport Agency local spokesman Peter Connors said.
The tunnel, built in the 1960s, links Christchurch to the port of Lyttelton.
More than 140 aftershocks have rattled the region since Saturday, and earthquake experts warned on Tuesday that another strong temblor might hammer the region in coming days.
The weekend’s powerful 7.1—magnitude earthquake smashed buildings and homes, wrecked roads and disrupted the central city, though nobody was killed and only two people were seriously injured, which authorities attributed to good building codes and the quake’s early morning timing.
“It was as strong as the earthquake in Haiti earlier this year, which caused widespread devastation and is estimated to have killed approximately 230,000 people,” Prime Minister John Key said. “Although no one lost their life ... families have been traumatized and lost their valued possessions.”
On Wednesday, Mr. Key travelled north of the city to inspect houses in the town of Kaiapoi that had been torn from their foundations by the quake.
“It shows you how well the building code works in New Zealand as they had been picked up, ripped apart and yet the structure has survived enough that people could escape,” Mr. Key said after looking through one wrecked house.
“As this disaster unfolds what we’re seeing is some areas are much more badly affected than we thought they were, and, in fact, the damage is much greater than we thought it was,” Mr. Key told reporters.
The city centre remained cordoned off by troops on Wednesday, as authorities extended a state of civil emergency for another seven days. Only building owners and workers are allowed into the central city to begin clearing up the mess, with much of the centre taking on the mantle of a ghost town.
Quake experts said aftershocks likely will continue for several weeks, and the worst of them may be yet to come.
“It is still possible that we’ll have a magnitude—6 in the next week, and people ought to be aware of that, particularly if they are around structures which are already damaged,” said Ken Gledhill, a monitor at GNS Science. “For a shallow earthquake like this, they will go on for weeks.”
Mr. Key called off a planned nine—day trip to Britain and France, citing what he called the quake zone’s continuing “instability.”
The New Zealand government has said it plans to pay at least 90 percent of the hundreds of millions of dollars needed to rebuild Christchurch’s water, waste water and road infrastructure.
In a statement on Tuesday to Parliament, Mr. Key pledged to remove bottlenecks to reconstruction and said the government “is prepared to step up financially to rebuild the region.”
The main quake struck at 4-35 a.m. on Saturday near the South Island city of 400,000 people, ripping open a new fault line in the earth’s surface, destroying hundreds of buildings and cutting power, which has been gradually restored in recent days.
The government has said that at least 100,000 of the region’s 160,000 homes sustained some damage.
New Zealand sits above an area where two tectonic plates collide. The country records more than 14,000 earthquakes a year, but only about 150 are felt by residents. Fewer than 10 a year do any damage.
New Zealand’s last major earthquake registered magnitude 7.8 and hit South Island’s Fiordland region on July 16, 2009, moving the southern tip of the country 12 inches (30 centimeters) closer to Australia.