Posts by ChrisW
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Interesting thanks Joe - implying no great change in land levels, drainage.
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Hey Joe, how flows the Avon by your place? Apart from discolouration, does the relative level and flow look something like normal again or significantly different from before?
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Glad to see you're coping well Craig. I had something more like this Ian Scott
in mind, perhaps with hula hoops. But agreed we change the subject -Kelvin Berryman on Nine-to-Noon - excellent job on communicating the seismic-geological context, and the degree of uncertainty there must be in how the pattern of aftershocks plays out.
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Sorry.
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Provided Whaleoil is read literally and not personified, I think an image of Craig and Whaleoil moving in elevated and more elevated blue circles has the potential for a great artwork. Could go on a tee-shirt.
Joe Wylie again? No need to set it to music though.
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Key said the $2b estimate came from a Treasury model that had been developed for the Gisborne quake.
Translated, I think that will mean Treasury (and some geotechnical people perhaps too) came up with a model and used the cost of the Gisborne earthquake as a data point to calibrate it. I remain sceptical.
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Liquefaction - what happens when you push one of your feet around in the wet sand on a beach and as a consequence the previously solid-feeling sand "liquefies", your foot sinks into it and water is squeezed out to the surface.
Scaled up - vigorously shake wet sandy sediment (maybe sandy layers buried within muddy silt) and the pore-water between the sand grains is pressurised tending to hold the grains apart, tending to "liquefy" the sediment. Sediment compacts a little, sand grains settle and repack closer together, the pore water is squeezed out/upwards under pressure, tending to concentrate into particular channels on the way so carrying muddy sand in suspension and squirting it out onto the surface as sand volcanoes.
Meanwhile any foundation strength of buildings thereon ...
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On the total billions and EQC's cash - I don't think the total cost of the earthquake being guessed at refers only to the costs that will be met by EQC, but to the total cost.
EQC meets the first $100k + GST needed for each insured dwelling, any more on such dwelling is for the insurance company. And it covers local authorities for infrastucture etc. And not churches, commercial properties, etc., nor uninsured residential property. ?
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Kia ora to Cantabrians. I’m very conscious that we in Gisborne got off lightly in the 2007 earthquake – your earthquake (Magnitude 7.1, sourced 40 km west of central Christchurch) was of the severity Gisborne might have expected as the big one. But instead ours (M6.8, sourced 60 km away out to sea) at its worst was a notch down at MM7 rather than MM8 in parts of Christchurch, on the Modified Mercalli scale of earthquake intensity. (Not to be confused with the one measure of Magnitude for each earthquake – intensity varies with distance from the earthquake source, distance allowing for focal depth of that source, not just map-distance to the epicentre.)
So my losses in a well-built 1970s timber house on a concrete pad on firm ground totalled one jar of marmalade, while next-door neighbours in an old cottage on piles lost their chimney and more.
An amazing thing to me was that the apparently modest amount of visible damage in Gisborne and environs ended up costing around $60 million. So I find it hard to believe the much higher intensity and infrastructural damage over a much larger area with at least 15 times the population will end up at only $2 billion. I find a 2.5 multiplier on initial estimates works really well in many circumstances and suggest this will be one.
From Gisborne experience, repair of the priority infrastructure will be well organised and won’t take as long as might be expected. For owners of damaged houses, Gisborne gave EQC etc valuable training on managing the processes – it will be fairly good but with potential for plenty of exceptions and difficulties with the huge demand when it comes to implementation.
And there will be major difficulties with commercial buildings, over disagreements on style of the repair/rebuild, and insurance companies paying only for rebuild to equivalence of previous state rather than paying for upgrade to earthquake standards that those buildings for the most part did not comply with previously. Leaving owners with financial dilemmas and more that will go on for years. There will be intense local politics in all this, Bob Parker no doubt thinking ahead.
Mark Quigley (CU geologist) was very good on the Morning Report special this morning on the nature of the earthquake and identifying the surface rupture above the earthquake source. So this is a previously unknown fault in the middle of the Canterbury Plains, conforming to the pattern of plate boundary faults to the north, with up to 3.5 metres of mainly lateral displacement. Confirming there is a degree of surprise at the severity of the earthquake in Christchurch. Previously the most likely damaging earthquake in Christchurch was expected to be from a great earthquake much further away on the Alpine Fault or one of its well-known off-shoots – hence my comment stranded on the Random Play thread, posted yesterday morning in the same minute Jolisa launched this one -
Best wishes to the Cantabrians in dealing with your surprising earthquake, stirring up under the Canterbury plains, determined to demonstrate the "ongoing dynamic geological character of NZ".
Where “surprising” in respect of the earthquake was for its intensity in Christchurch and for its source, not that Christchurch had experienced a damaging earthquake at all.
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Best wishes to the Cantabrians in dealing with your surprising earthquake, stirring up under the Canterbury plains, determined to demonstrate the "ongoing dynamic geological character of NZ".
And best wishes to Stuart Keith on RNZ National, acknowledging that "Good Vibrations" might have been Random Play rather than a good choice for a filler in their news/information replacing Storytime before 7am.