Aardbeving (6.3) treft Christchurch, NieuwZeeland

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Op dinsdag 22 februari 2011 11:21 schreef Roel_Jewel het volgende:

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Denk dat het ook zeker meespeelt dat ze nog niet zo lang geleden al een relatief zware beving in dat gebied hebben gehad waardoor gebouwen verzwakt zijn.

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NZ Quake Is Linked To Bigger Tremor In 2010

A deadly quake that hit Christchurch is among a series of aftershocks that have affected the city since it was struck by a larger tremor last year, experts have said.

Thousands of aftershocks have shaken the South Island region since the 7.0 magnitude quake on September 3, 2010.

That tremor damaged up to 100,000 homes in the Christchurch area but caused no deaths.

According to geologists, the damage following the latest 6.3 magnitude quake was worse than the 2010 event because it was not as deep and the epicentre was closer to Christchurch.

As a result they say the shaking intensity - the force that affects rigid structures like buildings - was much greater than for the quake last year.

In some parts of the city, the effects of the earthquake are believed to have been amplified by a phenomenon known as liquefaction - where some types of soil lose strength and stiffness because of the tremors.

Christchurch is built on silt and gravel, with a water table beneath.

In an earthquake, the water rises, mixing with the sand and turning the ground into a swamp and swallowing up sections of road and entire cars.

New Zealand lies in an actively seismic zone and experiences up to 15,000 earthquakes are year. Of these between 100 and 150 are large enough to be felt.

According to historic figures, New Zealand can expect several magnitude 6 earthquakes very year - with a magnitude 7 quake likely only every 10 years.

The largest recorded quake hit the country in 1855 and measured 8.2 on the Richter scale.

It affected New Zealand's capital, Wellington, on the south of North Island, and raised land levels by up to 10ft (three metres).

The world's fifth biggest recorded earthquake struck Chile in February last year.

Measured at 8.8 on the Richter scale it killed more than 450 people.

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Gletsjer breekt af door aardbeving Nieuw-Zeeland

AMSTERDAM - Als gevolg van de aardbeving in Christchurch dinsdag is dertig miljoen ton ijs afgebroken van de grootste gletsjer in Nieuw-Zeeland.

Gidsen bij de Tasmangletsjer in de Zuidelijke Alpen hebben gezegd dat door de aardbeving stukken ijs van de gletsjer zijn afgebroken, die vervolgens ijsbergen vormden in het meer waar het smeltwater van de gletsjer in uitmondt.

Volgens toeristen op de rondvaartboten bij de gletsjer veroorzaakten de ijsblokken golven tot wel 3,5 meter hoog.

De gletsjer ligt op zo'n 200 kilometer van Christchurch. In de stad zijn zeker 65 doden gevallen. Er wordt vermoed dat nog meer dan honderd mensen onder het puin van ingestorte gebouwen liggen.

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Deathtoll revised to 32, could reache 300
The official death toll from yesterday's earthquake in Christchurch has been revised to 32, but there are fears it could reach as high as 300.

Speaking to reporters at the Civil Defence bunker in Wellington this morning, the agency's director, John Hamilton said the number of confirmed dead in the earthquake was 32 not 65 as Prime Minister John Key said last night.

But Mr Hamilton said fatalities were only officially confirmed once bodies had been identified and their next of kin informed. He would not provide an unofficial death toll.

There was still no list of the missing or numbers trapped, he said.

Mr Hamilton said eight people were rescued from the Pyne Gould building and three from the CTV building overnight. About 22 people are understood to still be trapped inside the Pyne Gould building and six in the CTV premises.

He said rescuers were focussing on 10 buildings in the city.