Guys/Gals
Just a quick update on the major Earthquake that struck NZ north of Christchurch just after midnight.
They have decided that there was two quakes and they are still deciding if it was along the Hope faultline which runs SW to NE and forms the hills that are between the Southern Alps and the east coast.
It would seem that this triggered many others right up the North Island so the effects were felt widespread.
I'm in Chch and was up at the time. It went on for 2-3 mins which is much longer than the previous ones.
The closest place is Kaikoura and it has caused some damage to houses, but has currently cut the road link that goes up the east coast (State Highway 1), and damaged other roads that could form an alternative route.
There was a Tsuanami warning issued, but got downgraded to a coastal warning.
Unfortunately these warnings end up much less than predicted, so if we actually get a real one, then I'm afraid many will ignore it.
For those that haven't experienced Earthquakes, they can be very disturbing to some people.
There is often little/no warning and while it might be a little bit of shaking at first, you have no idea how long it will last, or if it will get worse.
NZ sits on the junction of two plates and one is going under the other. The movement is constant, but various bits get stuck and then suddenly release as the stress overcomes the friction.
This release often results in extra loading on another part and triggers an aftershock which can be almost as large.
So far there have been 50 or more aftershocks in and around the area, so you get no rest from them.
As you can imagine you lose power, your house gets trashed and you get no rest, so it's quite stressful in the affected are.
The christchurch event in 2010 had around 14,000 aftershocks varying down to only just detectable without instruments.
So this will last for some days and it may trigger more events.
If you have friends and relatives in NZ, do try to make contact but appreciate that cellphone systems get overloaded and texts are the best way to contact them.
Cheers
Mark
