Quake shakes South Island

Warnings of a possible tsunami in Southland were issued by Civil Defence officials last night, after a huge earthquake in Fiordland, measuring 7.8 on the Richter scale, which was widely felt around the lower South Island, including Timaru.

As The Timaru Herald was going to press it was reported that officials, concerned by widely varying measurements of the quake, had decided to warn of a "potential tsunami" in Southland.

"We've had big differences in the measurements of the quake, ranging from 6.6 by GNS Science, to 8.2 by a tsunami warning centre in Hawaii we're issuing a precautionary message," an emergency management spokesman in Wellington, Vince Cholewa, said. Mr Cholewa said the initial United States Geological Survey measurement used by the Hawaii tsunami centre was quickly downgraded to 7.8. GNS later upgraded its reading to 7.8 from its initial 6.6

There were no immediate reports of casualties or major damage from the quake.

GNS Science reported it struck at 9.22pm, centred 100km northwest of Tuatapere in western Southland, at a depth of 12km.

In South Canterbury, the earthquake sent light fixtures swaying in Pleasant Point, and had one woman from Springbrook, near St Andrews, feeling like she had taken a "woozy turn".

Judy Keen and her daughter Joylyn, who lives in Pareora, both felt the quake. Mrs Keen said the bird cage in her home was waving around and everything "jangly" in the lounge was swinging.

Many Timaru residents reported feeling the quake, including Bill Matthews.

"My daughter called me (from Pleasant Point) and said her whole house was shaking."

Police and the fire service here said there had been no reports of damage.

The Southland Civil Defence Emergency Management Group activated the region's emergency operations centre to assess damage reports.

CDEM Group Controller Neil Cruickshank said it was believed the epicentre was a considerable distance from any township.

An Invercargill man told NZPA the initial quake lasted at least a minute. "Things just started to rattle a bit, then the house started to sway."

He and his wife got their three young children out of bed and huddled under the dining table to wait it out. Cracks had appeared around several doorframes, he said.

Invercargill police Inspector Olaf Jensen said there were no immediate reports of damage, but the quake was significant enough to send staff into doorways.

He described it as a strong, rolling quake rather than a sharp jolt.

The Pacific Tsunami Warning Centre in Hawaii issued the warning soon after the quake struck. The centre said it was not known if a tsunami was generated, but it was issuing the warning based on the earthquake evaluation. "An earthquake of this size has the potential to generate a destructive tsunami that can strike coastlines in the region near the epicentre within minutes to hours," it said.

A magnitude 6.7 earthquake which struck Fiordland at 1.29am on October 16, 2007 60km west of Milford Sound at a depth of 24km was the most recent previous big shake in the area.

But one of New Zealand's biggest quakes a magnitude 7.2 tremor hit Fiordland near Secretary Island off the Fiordland coast on August 22, 2003. It caused significant landslides in parts of the region.

The first aftershock from last night's quake was measured 19 minutes later, at 9.41pm by GNS Science. It was a 6.1 magnitude shake at 5km depth 150km west of Tuatapere.

Power was off for five minutes in parts of Te Anau, and in some parts of Invercargill power lines came down and stock fell off supermarket shelves.

Neither the Manapouri Power Station nor the Tiwai Point Aluminium Smelter reported damage, but further assessments were due to be made today.

- © Fairfax NZ News