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.

Wellington Hit by Norwesterly Gales

Earning its title as "The Windy City", Wellington has been hit by northwesterly gales gusting up to 130 km/h, closing the airport, downing power lines, and closing the Rimutaka Hill road. More details here.

While air travel has been disrupted to and from the capital, Cook Strait interislander ferry sailings are experiencing only minimal difficulty in 1 metre swells, southerly gales typically causing higher swells in the Strait than westerlies.

Heavy rain accompanied the gales, with rapidly rising river and stream levels expected. Some slips may also occur. Heavy rain warnings have been issued for Taranaki, the central North Island, and western ranges of the Hawkes Bay and Gisborne.

A southwesterly cold front is following hard on the heels of the norwesters bringing cooler temperatures & an easing in wind strength although some gales may persist.

The Canterbury Nor'wester

Nga ra o te waru - the time of scarcity - as norwesters dry out the Canterbury Plains in January-February, the height of summer.

The Press in Christchurch reports that early spring gale force norwesters have fanned scrub fires in two locations around Canterbury, both starting from agricultural burn-offs. Such fires are but small echoes of the burn-offs precipitated by natural causes before human settlement and those successfully practiced by both Maori hunters and Pakeha farmers, the latter on a much wider scale in the 19th century.

The severe northwest gales extended over the Wairarapa, Wellington, Marlborough and Canterbury, with the highest wind gust of 158kmh being recorded on the Rimutakas north of Wellington.

New Zealand's oceanic climate leads to highly changeable weather conditions that any Kiwi will readily tell you about. Indeed, New Zealand band, Crowded House, sing of Four Seasons in One Day:

More on Canterbury's weather patterns & variability - a cool, wet southerly often quickly follows the hot, drying northwesterly leading to a sharp drop in temperature - can be found here.

Norwesters not only cause hot, dry conditions that can result in drought conditions and the need for irrigation in Canterbury agriculture, but can - under the right conditions - cause flooding on the plains because of heavy rains deposited in the mountains.

Tawhirimatea, god of weather, struggles to control his children, clouds & storms (the blue spirals). C Whiting, artist.

In Maori creation mythology (more here), Tawhirimatea, god of winds and storms, angered by the separation of his parents Ranginui (Rangi,sky father) and Papatuanuku (Papa, earth mother) by his siblings, sought revenge on his brothers Tane Mahuta (god of the forests), Tangaroa (god of the sea), Rongomātāne (god of cultivated food, eg kumara) and Haumia-tikitiki (god of uncultivated food such as the fern root). Tawhirimatea laid flat Tane's forests, caused waves to grow as large as mountains, and the kumara and fern root to burrow deep into Papa, the earth mother.

Finally, Tawhirimatea turned on his brother Tumatauenga, (god of war and people).

Tumatauenga, god of war & people. C Whiting artist.

Unlike his other siblings, Tumatauenga proved equal to his brother of the winds. Ever since those early times, the weather and people have been locked in a continual struggle that neither one can win.

So that, as Crowded House advise, "Everywhere You Go, Always Take The Weather With You" - more accurately, you have little choice but to learn to live with it, for better or worse: