A 7.8 is a hell of a shake. NZ is Stage 2 of "Hot Spot Evolution". Stage 1 is Hawaii and Stage 3 is Central America. So that region in NZ is not fun in terms of volcanic and tectonic activity.
Palef, I am assuming that you are near or in the Canterbury Plains? I remember most of my Historical Geology, as most rely on Wiki. Nor do some of these folks understand the mechanics behind soil liquefaction. I remember the 2010 Quake well as they discovered a previous unknown fault, as well as a rare foreshock, before the actual quake. What is not cool here, are the obvious 5-6 rating aftershocks that will follow over the next few months.
I'm actually in the North Island and we seem to be feeling the shakes more than Christchurch is. The Hope fault has developed a centre fracture at the top end and it is engaging with two other faults. We've had 382 aftershocks of more than M4.2 to date. We sit over a fault capable of generating M7-M8 quakes and there was a big one in 1942 that flattened a lot of the centre of the regional capital, Masterton.
The Hope fault is very close to the Alpine fault which is capable of generating quakes of M9 or greater. When the quake intensified last night my biggest fear was the the Alpine fault was rupturing. Expected casualties run in the 10s of thousands if that goes, spread across the centre of the country. One of the towns closest to the main event, Kaikoura, is cut off with lots of damage and no power or swewrage. Kaikoura is/was a lovely spot too.
We're a very underpopulated country and the South Island has less than a million people, so the main highway is a bit under developed. It still has awkward tunnels and one lane bridges. The tunnels just North of Kaikoura are buried under a massive landslide, and the road to the South of Kaikoura is fundamentally closed due to gaping chasms in the roadway an damage to bridges. At the moment the Airforce is concentrating of airlifting tourists, as that is the only way out at present.
Where I live, Greytown, if we have a severe quake close to our location, I suspect we'll be drowning in liquefaction. The water table is only inches below the surface, which makes for great pastures and orchards, but people here empty their swimming pool at their own peril. Leave it empty long enough and it floats out of the ground.
