I wonder what odds a bookie would give me for a bet on Christchurch NZ not existing within ten/twenty years?
I did posit some months ago that they would do well to move the city re the geology plus tectonics but was dismissed in pretty short order as ‘not knowing what I was talking about’. Seems the exodus has already started. One tenth of the population has already left. With this new round of earthquakes destroying the relaid sewers etc etc it is only a matter of time before any rebuilding will fail to get any takers for insurance risks. Who will rebuild traditional style at their own risk? Not many.
I rather think that they have moved over a hot spot, ie the land mass has gone to the right and is now unfortunately situated over an effective ‘cauldron’. This seems to happen all over the world, by studying caldera of previous eruptions and earthquakes, they move, albeit slowly over the aeons. But it is in fact not the hot spots moving but the granitic continents above drifting about like scum on strawberry jam. The movements are not random, they are moving back in a pendulum style movement together as in the old land mass of Gondwanaland. This can be seen quite clearly in Yellowstone and some parts of Indonesia.
Interesting subject, but I would cut my losses if I lived in Christchurch! More to life than rebuilding the town every five minutes. I don’t think it is going to stop any time soon. Or else they had better start building to Japanese code standards.
Boadicea's Chariot 
I agree, and from what I heard on the news this morning, some of the inhabitants of Christchurch have decided to cut their losses and get out.
Interestingly, those who live on the San Andreas fault seem to hang on in there. Better building standards possibly? I have no idea, but they know it’s going to blow eventually.
Minty: are you giving me any hints? Ha ha.
If a major earthquake were to hit California a number of people would see their lives be made
a trifle more difficult. Some parts of San Francisco, especially the Financial and Marina Districts, would likely fall into the water as they were built on debris from the 1906 earthquake. Western San Francisco will also be badly affected as it is built on sand. There would also be some flooding in parts of the Delta Region. Too many houses were built on highly unstable land. Not too long ago I read that even a moderate earthquake could cause over 1 million people to lose electricity for at least a year.
A differing geology, the San Andreas is rather reliable, the land to the left of the fault goes North and sinks at each jolt which are continual. Of course, in the end the whole of coastal California will go into the sea. The constant quakes reduces the stress which dissipates the need to have a massive shock. The 9, plus is reserved for us up here in the NW where the stresses go unrelieved! (Why I wouldn’t buy nearer the sea!) Meanwhile they try to keep construction to a minimum ACROSS the fault, a lot of things like pipelines and aqueducts are above ground with shock absorbers in that section, obviates the necessity to keep rebuilding it. Plus the houses are mainly one/two storey wood with a very much higher code. 1906 San Francisco had a very positive effect on the rebuilding!
Interestingly there is an area around Santa Maria, right on the fault that has no earthquakes at all, virtually ever. There the fault runs through huge deposits of talc as in talcum powder, acts as a natural shock absorber and kills earthquakes stone dead.
This is the problem with Christchurch, very bad geology that amplifies the bad effects of the earthquake plus all this dreadful liquefaction, so the land surface heaves and subsides in liquid form, like trying to build your house on the sea! (Or not far off!)
Grim for them.
Good evening, CO.
Thanks for this. It is, as you say, interesting for those of us who do not live there. It would scare the bejasus out of me if I did live anywhere near there.
The reports on the most recent tremors appear to be upbeat and saying that all rebuilding will be to the highest possible earthquake-proof standard and that it will probably all be all right in the end.
But, when you say that they have moved over a ‘hot spot’, do you mean that they now have a serious chance of surface volcanic activity as well as further tectonic plate movement?
Every so often, an Internet allusion takes me racing back in time and place. Your ‘scum on strawberry jam’ did that for me. It made me remember helping my Great-Aunt Aggie as she brought that season’s jam to perfection in her mum’s jeelie pan. In time, my mum inherited the pan and I now own it.
Mrs M is doing not bad with it, to be fair, but I think that might be down to to my inculcated and inspired stirring.
Thank you, Tina and Christopher, very interesting. I suppose I’m just relieved that I don’t live in these areas.
Chris, I agree with you SF is a special case and would do as you say but the rest of it is at least reliable in its brand of being unreliable!
So to speak!
Also there is the added ‘jolly’ of Baja California going under first! You at least get to watch that go under from North of the border and the Gulf of California getting bigger by the minute, OK I exaggerate, by the year/decade/century/age/aeon!.
JM Short answer, yes!
Hot spots appear to be where the earth’s crust is either thin or perforated in some way, there is not the usual layer of highly dense rocks that normally protects us from the core. Magma comes far nearer to the surface and melts local rocks to make a huge chamber, miles long and deep. This chunders along for the odd few million years and then something happens and all hell breaks loose, pressure is generally exerted by movement of rocks from above, ie continual continental drift or insertion of new material from below ie subduction zones or the bottom of rift valleys. The net result it has to go somewhere and will make its way to the surface at the least strong point, generally pre-existing volcanoes but not always by any manner of means.
Oops, both our West Coast and NZ rejoice in such geology.
They know full well that the hotspot in Yellowstone has moved over 40 miles from its original caldera quite recently, nasty!
And, geologically is well overdue to blow again. There the magma mega chamber is constantly monitored for pressure but there is not a dammed thing they can do about it short of nuking it which would have an equally deleterious effect on the surroundings, if not worse!
I darkly suspect that NZ is not anywhere nearly studied as much in that they rely on the US Geological service to monitor their earthquakes for them, plus there is very little population on South Island, it is mainly sheep farming on the East coast and unliveable on the West due to rain and steep landscape. The volcanoes in the middle are studied extensively.
I do know that on the seaward side of Christchurch is a very old volcanic plug, heavily eroded that putatively could get a new lease of life but I would have thought that would take a few hundred years at lest to get going again!
It really does behove some geologist to study the area seriously because if that is the case it is a fool’s errand to continually try to rebuild the town there, especially when they would be much safer to the North.
What I personally really don’t like is that liquefaction, shows a great and ongoing weakness. Not good news at all, an excess of porosity and some serious shatter faulting below in geological terms.
It is a case of the old Biblical don’t build your house on the shifting sands but on the reliable rocks!
Anyway, must away to make profiteroles! We are going to out to dinner to someone who cannot make desserts! Well at least none that I would eat, just disgusting Yank messes! Better to take the pud than the wine, called self preservation of one’s intestines.
Its a wonder I have any friends left!
Perhaps they are all masochists at heart!
Typed in haste pleas ignore typos if there are any.
Fascinating stuff. I have been to Christchurch, in late 80’s. Lovely place.. but not if recurrent earthquakes are going to happen
Thank you for your post and comments, Christina. Fascinating, but worrying. We spent three weeks in the Azores a couple of years ago, where there is ample evidence of volcanic activity. I feel very sorry for the people of Christchurch. A very hard decision to make.
We’ve always had a great friendship / rivalry with most things New Zealand.
Christchurch is of course home to the mighty Canterbury Crusaders, probably NZ’s flagship rugby franchise. One of our South African teams played an important title match against them at Twickenham, London, in an effort to raise awareness and raise much needed funds for the Christchurch appeal.
Our national cricket team will be touring NZ in February, our cricketers asked for an extra warm up game and asked that it be played in Christchurch, a game has been scheduled against the Canterbury Wizards on February 15, 2012 at Hagley Oval in Christchurch, these latest quakes and liquefaction have probable put paid to that idea, hope not.
Of course, time was, CO, when homo sapiens avoided settling on dodgy ground and ensured later generations avoided the mistake by passing down sagas detailing the fate of less canny folk. Your comment on the Biblical shifting sands refers!
Janus, bang on. There is a small town called Crescent City in N. California. Had anyone had one iota of sense they might have listened to the Indians before settling there. The Indians in the local language have rather a long name for it that roughly translates as ‘a good place to fish but a bad place to sleep’ there never was an Indian settlement there. Needless to say, if there is any tsunami in the whole Pacific basin headed for the Americas it hits Crescent City first!
The Japanese one this year drowned two people on the beach there and it was only technically 3/4′ high. there have been some absolute humdingers there in the past, positively dozens geologically and more than a few historically that are recorded in Indian oral histories. needless to say nobody bothered to find out!
I’ll lay you odds the Maori have some extravagant tales of boiling sands round Christchurch which were dismissed as hyperbole. Trouble is they were true, it really does boil, several pieces of film on the net showing the phenomena, utterly bizarre visual. There is a piece of film showing sand boiling in the 1880s on the Mississippi river in the Kentucky area to the left of Reelfoot Lake, fortunately it has never been anything other than farmland, still does it every time they have an earthquake it produces geysers of sand boiling like Old Faithful all over the place.