Swamp: The Cautionary Tale of Sir Launcelot

23Mar11

“One day all this will be yours….I brought this kingdom up from nothing. When I started here it was all swamp…they said it were daft to build capital in a swamp…. it sank into the swamp….four times…”  Monty Python’s slow seismic learner Sir Launcelot*

The pukeko have finally come home to roost in Christchurch. It was not Ken Ring but Monty Python who accurately predicted the nature of the Feb 22 Christchurch Quake and pointed out the challenges of building on a swamp. And it was the sun that featured, not the moon.

In the animated Python video clip below, earthquakes are caused by errant clouds and a prodigal sun trampolining near an old stone building*.

The trampoline effect is just what happened.  Not the soft-edge trampoline developed by Keith Alexander at the University of Canterbury a decade ago but a very hard-edged tectonic alternative.

Apparently when the earthquake hit, the weaker top few metres of ground under the city “trampolined” further upwards than stronger layers lower down and separated from them.* GNS Science seismologist Bill Fry explained the high impacts thus:
“Think of jumping on a trampoline. If you change the rate at which you jump, and get out of synch with the trampoline, when you come down and land as the trampoline is still heading upwards, you get quite a jolt to your knees.”

Ground acceleration more than twice that of gravity in some parts of Christchurch was the strongest recorded in a New Zealand quake and up to four times greater than the maximum acceleration measured in last week’s magnitude 9.0 quake off northeast Japan.

There have been isolated recordings of the trampoline effect in the past, but Christchurch’s 22 February Quake has provided scientists with comprehensive data. We’re living in a seismic laboratory.

While they study that and other data developers are accelerating plans to develop single story temporary business premises on the outskirts of Christchurch, while the central business district remains in quarantine.

The Doughnut Effect is, at least temporarily, in full flow. We get the Phoenix flavour  but the city’s rebuilding slogan should not be Rise Up Christchurch! but Flatten Out!

Those Deans brothers at Riccarton knew a thing or two when they went Bush.

 *BLINKS

http://www.youtube.com/watch?v=JE9StK1HIos   Vid Monty Python and the Holy Grail, Part 6     (Fast Forward to 2.40-4.41)
http://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/4781978/Rare-mix-of-factors-exacerbated-quake 
http://www.stuff.co.nz/business/industries/4800961/Outer-Christchurch-developed-after-earthquake
http://lukeytraining.wordpress.com/2011/03/12/seismicity-graphic-quake-warning-http://lukeytraining.wordpress.com/2011/03/02/christchurch-quake-ii-crisis-and-opportunity/ignored/

 #Lyall Lukey 23 Mar 2011
http://www.lukey.co.nz/  http://www.smartnet.co.nz
http://lukeytraining.wordpress.com/ My other (bit more serious) blog

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One Response to “Swamp: The Cautionary Tale of Sir Launcelot”


  1. 1 Thinking Inside The Square « Blugger me

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