Earthquake in Christchurch

From Wikipaedia:

The 2010 Canterbury earthquake (also known as the Darfield earthquake and the Christchurch 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. It caused widespread damage and several power outages, particularly in the city of Christchurch. Two residents were seriously injured, one by a falling chimney and a second by flying glass.One person died of a heart attack suffered during the quake.

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.

The Civil Defence declared a state of emergency for Christchurch and Selwyn District, while Selwyn District, Waimakariri and Timaru activated their emergency operation centres. A curfew was established in Christchurch Central City from 7:00 pm to 7:00 am in response to the earthquake.

Effects outside Christchurch

The quake's epicentre was around Darfield, around 40 kilometres (25 mi) from Christchurch. Four metres (13 ft) of sideways movement has been measured between the two sides of the previously unknown fault.

A 5 km (3.1 mi) section of rail track was damaged near Kaiapoi and there was lesser track damage at Rolleston and near Belfast. As a precaution, state rail operator KiwiRail shut down the entire South Island rail network after the earthquake, halting some 15 trains. After inspection, services south of Dunedin and north of Kaikoura recommenced at 10:30 am. The Main South Line, linking Christchurch with Dunedin, was given the all-clear and reopened just after 6:00 pm to allow emergency aid to be railed into Christchurch.

The quake caused damage to historic buildings in Lyttelton, Christchurch's port town, including cracks in a church and the destruction of parts of a hotel.

It's just surreal an unbelievable the extent of damage

Thank goodness that there (at this stage) seems to be only 2 people seriously hurt.

The horrible thing is they are still having after shocks which are keeping them on edge - recent Earthquakes

Here are some photos of some of the devastation:

         

There are some more unbelievable photos here: Dominion Post photos of earthquake

A lady on a parenting board I visit share her experience:

The worst part of it (one the shaking had stopped) was waiting it out in the pitch black for daybreak. We had the four of us in bed together and everytime there was another shake we all grabbed hold each other. DS2 was shaking constantly (obviously shocked) and no matter how tightly I held him he was still making the bed shake. We've got drawer handles that hang and everytime there was an aftershock they started clattering like some strange demonic musical instrument.

A friend of ours is a volunteer fireman and his wife dropped him at the station straight after and then she spent the next hour or so picking up people wandering the streets and dropping them off with family. It seems that a few of the elderly were wanting to be with family so decided to walk rather than spending then next few hours terrified and alone.

It was a huge relief when it finally lightened up, we only had minimal damage, a few broken glasses and a flood in the toilet where it overflowed, once DH worked sorted it out he went to his SILs to see how they fared. All of our friends sort of rallied together and the pregnant and BFing mums hung out at one house with the children while everyone else whet around the area checking on others and helping where needed. They spent a fair few hours at the pub and bottle store as there was broken glass everywhere. It was nice to see that people seemed to group together and were pooling together resources to ensure everyone was fed and watered. There were plenty of BBQed sausages and bacon butties eaten yesterday.

Even last night we all had dinner together before returning to our own homes although some people stayed over, especially those who live alone. It was the worst experience of my life but I could not imagine the terror of having to go through that without another soul in the house.

I am so very thankful of what we've got, a house that is standing, a fire for warmth, power and water and best of all my family are safe. I feel strangly contented, in no hurry for anything just happy to enjoy what today brings (minus the aftershocks of course). I also find myself on the verge of tears quite often, there is no apparent trigger for this, just a really somber feeling comes over me but still so happy to be here!

What causes the Earthquakes in New Zealand is fully explained here: GNS Science 

New Zealand is located on the boundary between two of the Earth's great tectonic plates - the Australian and the Pacific. Broadly speaking, the Australian plate is heading north while the Pacific plate is heading west. The combination of these motions means that the Pacific plate, which includes much of the South Island, is moving relative to the Australian plate at a rate of about 40 millimetres each year in a southwesterly direction. So Christchurch is moving away from Auckland about 4 metres every century.

It is the motion between these two plates, and the deformation that occurs in the boundary zone between the plates, that has given rise to much of New Zealand's geology as we see it today. It is also the fundamental cause of the earthquakes and volcanic eruptions that are such important natural features of New Zealand. The deformation and squashing caused by the collision of the two great plates has caused mountain ranges to rise throughout the country. Some of these are still rising, and the interplay between the tectonic forces pushing the mountains up and gravity trying to pull them down means that landslides are a common occurrence over much of New Zealand.

The plate boundary zone in New Zealand

Click on thumbnail for bigger image

Tectonic plates behave like rigid shells that slide over the surface of a sphere. The biggest plate, the Pacific, is more than 10,000 km across. The plate boundary zones - the zones of interaction between adjacent plates where they collide, pull apart or slide past each other - may be anything from a few kilometres to a few hundred kilometres wide. Almost all of New Zealand is in the deforming plate boundary zone.

Only Northland is fully on the Australian plate, and only offshore islands like Chatham Island and Campbell Island are fully on the Pacific plate.

Large earthquakes are the most obvious sign of the deformation between the two plates.