Severe Weather Next Test for Christchurch?

Severe nor'westerly gales in the next few days followed by a southerly cold front with rain (the usual climatic mood change in Chch) may be the next test for Christchurch's residents.

The Met Service and emergency services think that the nor'westers may loosen masonry and topple unstable buildings that haven't been made safe by demolition. And, with many damaged buildings exposed to the elements, any rain brought by the southwesterly will likely just compound matters.

Plenty of aftershocks apparently, but not the one big one of a 6 or so that often hits in the first 48 hours after the major one. Seismologists think the big one may acutally have been three quakes close together, but I'm sure most Chch residents regards that as all academic right now.

Power must be on in enough places around Chch for me to be getting direct & indirect reports from family & friends that they are safe & well, most have suffered only minor damage to property but folks like Sandy's parents & neighbours in comments to a previous post below obviously have been hit hard.

"Our man in Burwood" - my big brother - reports a lot of liquefaction of the soil, a phenomenon produced by the quake, has caused a lot of subsidence in east Christchurch of the type Sandy reports in her comment. In addition to buildings being damaged, ruptured water pipes and sewers are the result.

Some on other sites are commenting that they thought the Big One would be in Wellington, not Christchurch. Wellington will have its Big One again - it had huge ones in the 19th Century, the Wairarapa quake being the worst. But no one should have been under any illusion Chch couldn't have one. The effects would simply be different because the city is essentially a drained swamp and Plains are alluvial flood plains. Growing up in Chch, we were always drilled on earthquake preparations & cover and left under no mis-impression it could help in good old Chch.

ANYWHERE in New Zealand is fair game (poor choice of term, perhaps) for earthquakes being on the Pacific Ring of Fire - that's quakes, volcanic activity, and tsunami. Did I miss anything out?

That said, I think if I was to go through a big quake I'd prefer to take my chances in Chch over Wellington, having lived in both cities. Wellington sits on top of several major faults, including the Main Divide fault that bi-sects New Zealand north to south. Dealing with recovery and clean-up on hillsides would likely be more difficult as well compared to the flats of Chch.

Moreover, access into & out of Wellington is limited to a few choke points that if blocked would hamper the ability to evacuate or get assistance into the city. The airport itself sits on reclaimed land uplifted by the Wairarapa quake in the 19th century. Years ago I read that the then Ministry of Works parked a bulldozer at the top of the Ngauranga gorge each night, ready to start work on clearing a passage in the event the gorge highway is blocked by rock slides caused by a quake. That's provided the driver could get there and her 'dozer hadn't been lost down the hillside...

But as my late mother, a proud life-long Christchurch resident, would say "don't borrow trouble". Then she'd put a kettle on for a cup of tea for the "poor beggars" who were "worse off than me" and then go grab her broom, mop, and bucket so she could pitch in. For all that, I'm glad Mum didn't go through it. All the best to those who have & now must clean up the mess.

Major Earthquake in Christchurch

Major 7.4 earthquake hits Christchurch, my home town! Most of my family lives there, but I haven't for a long time. Last back there in June - and not even a hint of a shaker ;)

Earthquake struck at 4:35 am Saturday, epicenter was some 30 km west of Christchurch and was shallow just 10 km down. Not on the major Alpine fault, but a minor one that seismologists didn't expect to cause much trouble. But large, shallow quakes can be damaging, apparently.

Radio New Zealand is providing very good coverage. Apparently couple of major injuries, no deaths. A lot of close escapes from falling chimneys collapsing into bedrooms.

Significant damage in centre of city. Water, power, and sewage out in many parts of city. Most damage to older brick buildings. thank goodness for tight building codes. The port of Lyttelton has suffered some significant damage. A few bridges are unstable or otherwise damaged. Suburbs of New Brighton and Brooklands may be evacuated because of flooding and sewage problems.

Power company is saying an initial assessment suggests the power can be restored to about 90% of the city by nightfall today. The central business district will take longer as they need to isolate individual damaged buildings from the system first. It sounds like the water supply & sewage system will be out for longer.
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