Wednesday, February 23, 2011
Christchurch - This is 2nd time earthquake
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New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses (the North Island and the South Island) and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori name for New Zealand is Aotearoa, commonly translated as land of the long white cloud. The Realm of New Zealand also includes Tokelau; the Cook Islands and Niue (self-governing but in free association); and the Ross Dependency, New Zealand's territorial claim in Antarctica.
New Zealand is notable for its geographic isolation: it is situated about 2,000 kilometres (1,200 mi) southeast of Australia across the Tasman Sea, and its closest neighbours to the north are the Pacific Islands of New Caledonia, Fiji and Tonga. The country's sharp mountain peaks owe much to the earthquakes and volcanic activity caused by the clashing Pacific and Indo-Australian Plates. The climate is mild and temperate and most of the landscape is covered by tussock grass or forests of podocarp, kauri or southern beech. During its long isolation New Zealand developed a distinctive fauna dominated by birds, a number of which became extinct after the arrival of humans and introduced mammals.
They said New Zealand is the last land mass appeared on earth.New Zealand is a choice destination for holidays to many people.
Earthquakes occur regularly in New Zealand as the country forms part of the Pacific Ring of Fire, which is geologically active. About 14,000 earthquakes, most of them minor, are recorded each year. About 200 of these are strong enough to be felt. This affects the culture of the country, in the form of general awareness, historical events, disaster planning and building regulations.
Most earthquakes in New Zealand occur along the main ranges running from Fiordland in the southwest to East Cape in the northeast. This axis follows the boundary between the Indo-Australian and Pacific plates. Large earthquakes are less common along the central Alpine Fault, where the plates are not subducting and the forces are accommodated in different ways.New Zealand is sometimes nicknamed the Shaky Isles. Quite early on, European settlers were faced with the reality of earthquakes in their new home.
The largest city within this high risk zone is the nation's capital, Wellington, followed by Napier and Hastings. All these cities have experienced severe earthquakes since European settlement.
The New Zealand region of Canterbury (Māori: Waitaha) is mainly composed of the Canterbury Plains and the surrounding mountains. Its main city, Christchurch, hosts the main office of the Christchurch City Council, the Canterbury Regional Council and the University of Canterbury.
The Canterbury Region of New Zealand corresponds to the portion of the South Island to the east of the Southern Alps, from the Waiau River in the north, to the Waitaki River in the south.
To the west of the Southern Alps lies the Alpine Fault, a major fault boundary, that passes through the South Island from Fiordland in the south, to the Marlborough Region in the north, where it divides into multiple faults. The Pacific Plate lies to the east of the Alpine Fault and the Australian Plate lies to the west. The Pacific Plate is sliding SSW at about 35mm/yr, relative to the Australian Plate, and rising up 10mm/yr, generating the Southern Alps.
The Alpine Fault did not develop until early Miocene times (23 Ma). Ten million years ago the Southern Alps were low hills, and they only became mountainous as recently as 5 million years ago.
To the east of the Southern Alps are the Canterbury Plains, formed by the sediment eroded from the Southern Alps. On the coast, just southeast of Christchurch, is Banks Peninsula, composed of two large mainly basaltic Miocene volcanoes.
2010 Canterbury earthquake
The first time, The 2010 Canterbury earthquake (also known as the Christchurch earthquake or Darfield earthquake) was a 7.1 magnitude earthquake, which struck the South Island of New Zealand at 4:35 am on 4 September 2010 local time (16:35 3 September UTC).Mass fatalities were avoided partly due to there being few houses of unreinforced construction, although this was also aided by the quake occurring during the night when most people were off the street.The earthquake's epicentre was 40 kilometres (25 mi) west of Christchurch, near the town of Darfield. The hypocentre was at a shallow depth of 10 km. A foreshock of roughly magnitude 5.8 hit five seconds before the main quake, and strong aftershocks have been reported, up to magnitude 5.4. The initial quake lasted about 40 seconds, and was felt widely across the South Island, and in the North Island as far north as New Plymouth. As the epicentre was on land away from the coast, no tsunami occurred.
2011 Canterbury earthquake
The 2nd time, An earthquake of magnitude 6.3 occurred on 22 February 2011, centred on Lyttelton and at a depth of 5 kilometres (3.1 mi). The quake cracked tarmac on roads and burst water mains. Buildings also collapsed in the shake and so far 65 people have been confirmed dead and there are over 200 missing.
The 2011 Canterbury earthquake was a 6.3 magnitude earthquake which struck the Canterbury region in New Zealand's South Island at 12:51 pm on 22 February 2011 local time (23:51 21 February UTC). Centred 5 km (3 mi) below the town of Lyttelton, the quake caused widespread damage and multiple fatalities in nearby Christchurch, New Zealand's second-most populous city. It was the second strong quake in five months to hit Christchurch, a city of almost 400,000 people. About 120 survivors had been pulled from the rubble but the death toll was expected to rise.
This was the largest aftershock of the 4 September 2010 Canterbury earthquake, although in some respects it is being regarded as a separate earthquake. Although smaller in magnitude, the earthquake was more damaging because the epicentre was closer to Christchurch, and the September quake was measured at 10 km deep whereas the more recent quake came within 5 km of the surface. The February earthquake also occurred during lunchtime on a Tuesday rather than before dawn on a Saturday, and many buildings were already weakened from the previous quakes. The intensity felt in Christchurch was MM VIII.
On the day of the quake, Prime Minister John Key stated the current death toll was 65, saying that 22 February "may well be New Zealand's darkest day". Early the next day the Director of Civil Defence said that 38 deaths had been fully confirmed (meaning that the bodies were identified and the next of kin informed). There are unconfirmed reports that the death toll could reach 200–400. Mayor of Christchurch Bob Parker says at least 200 people are believed trapped under rubble, saying that New Zealanders are "going to be presented with statistics that are going to be bleak".
Many buildings were severely damaged, including the iconic ChristChurch Cathedral.
(source: mainly extract from wikipedia)
For latest development of the earthquake, http://canterburyearthquake.org.nz/, official council website on response information about the 22nd February 2011 earthquake in Canterbury, New Zealand – canterburyearthquake.org.nz is managed by Environment Canterbury
For Emergency helplines
0800 779 997
Red Cross Person Enquiry Line
0800 733 276
For enquiries outside New Zealand:
1. 2010 Canterbury earthquake, http://en.wikipedia.org/wiki/2010_Canterbury_earthquake
2. 2011 Canterbury earthquake, http://en.wikipedia.org/wiki/2011_Canterbury_earthquake
3. List of earthquakes in New Zealand, http://en.wikipedia.org/wiki/List_of_earthquakes_in_New_Zealand
4. Christchurch, http://en.wikipedia.org/wiki/Christchurch