Fri, 03 Sep 2010 13:50 UTC
Although many people with minor injuries sought treatment, hospitals said there were no reports of any serious injuries although doctors were on standby because of the intensity of the quake and the damage to buildings.
The quake struck at a depth of 16.1 kilometres some 30 kilometres northwest of Christchurch at 4:35 a.m. (11:35 a.m. ET Friday), the USGS said.
Roads in the seaside suburbs were packed with cars as residents moved inland but there were no tsunami alerts issued. A swarm of aftershocks were ongoing and police said damage was widespread throughout Christchurch, with electricity supplies cut to about half of the city of about 340,000.
Sewer lines were damaged and residents were being urged to conserve water supplies. Local resident Colleen Simpson told the Stuff website that many people had run out onto the streets in fear, while the mobile phone network was failing.
"Oh my God. There is a row of shops completely demolished right in front of me," Simpson said. Kevin O'Hanlon, from Mairehau in Christchurch, said: "Just unbelievable. I was awake to go to work and then just heard this massive noise and, boom, it was like the house got hit. It just started shaking. I've never felt anything like it."
The damage included structural harm to houses, broken glass and damaged bridges and vehicles. John Ristau, a seismologist at the government's GeoNet geological monitoring service, said the intensity was strong enough to cause structural damage to buildings.
The quake was felt through much of New Zealand's South Island where Christchurch is located on its east coast, local media said. Christchurch International Airport, the main international gateway to the South Island, has been closed and rail movement in the South Island has been stopped while facilities are checked.
The magnitude was revised downwards from an initial estimate of 7.4, the USGS said. Although there was no evidence of a tsunami, the Pacific Tsunami Warning Centre said an earthquake of this magnitude could generate a local tsunami.
"Earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a hundred kilometres of the earthquake epicentre," the centre said. "Authorities in the region of the epicentre should be aware of this possibility and take appropriate action."
Friday, September 03, 2010 at 16:35:46 UTC
Saturday, September 04, 2010 at 04:35:46 AM at epicenter
Time of Earthquake in other Time Zones
12 km (7.5 miles) set by location program
SOUTH ISLAND OF NEW ZEALAND
55 km (35 miles) WNW of Christchurch, New Zealand
185 km (115 miles) S of Westport, New Zealand
305 km (190 miles) NNE of Dunedin, New Zealand
325 km (200 miles) SW of WELLINGTON, New Zealand
horizontal +/- 11.2 km (7.0 miles); depth fixed by location program
NST= 98, Nph= 98, Dmin=86.7 km, Rmss=1.69 sec, Gp= 32°,
M-type=teleseismic moment magnitude (Mw), Version=8
USGS NEIC (WDCS-D)
Source: Agence France-Presse