Monday - March 07, 2011

Can’t Be Fixed

WELLINGTON, New Zealand – Some 10,000 houses in Christchurch will have to be demolished because of damage from last month’s earthquake and parts of the city will have to be abandoned altogether, the country’s leader said Monday.

The magnitude 6.3 temblor hit within three miles (five kilometers) of Christchurch and close to the surface on Feb. 22. It shattered homes, heritage buildings and office blocks, and caused 166 confirmed deaths. Officials say the toll is expected to rise to more than 200 as rescuers continue to search for bodies trapped in the rubble.

Earthquakes can cause sections of earth to liquefy and push up to the surface as watery silt, a process called liquefaction. In Christchurch, 260,000 tons of silt have already been scraped away.

“There are some parts of Christchurch that can’t be rebuilt on,” Prime Minister John Key told reporters. “The liquefaction damage from the ... earthquake is so great and the land damage ... is so significant we can’t remediate it.”

Key said some 10,000 houses will have to be demolished in the city, including 3,300 that were damaged by an earlier magnitude 7.1 quake on Sept. 4. That quake was deeper and further away than the Feb. 22 event, and did not cause any deaths or as much damage.

As well, several hundred central city commercial buildings will have to be bulldozed, Key said.

“Potentially there are some ... areas of Christchurch which will need to be abandoned and we will have to provide other alternatives for people to live in because the land has been so badly damaged, we can’t fix it — certainly not in a reasonable time frame,” he said.

Soil liquefaction is a geological phenomena that occurs when soil in a very high water table condition is subject to vibration. And it has been raining like mad this winter in the lands down under. The ground vibrations knock apart the cohesiveness of the soil, the water table drains in or gets squeezed up, and the soil almost instantly turns into quicksand. Christchurch had been hit by the Darfield earthquake back in September, and that 7.1 magnitude 40 second event started the process. Then came the rains.  The latest earthquake came on February 22 with a magnitude of 6.3. Because it had nearly the same epicenter as the quake back in September (24 miles apart is a geologic nada), it is considered to actually be an aftershock ( a reprise ) of the earlier quake. Other geologists argue that this one was it’s own earthquake, since it happened along a different fault line that they didn’t even know existed until the quake. I gather there are layers of those under the city. The February 22nd event was a very fast quake, more of a “pop” than a “slide”; described as a “strike-slip event with oblique motion”, some areas of land which moved vertically only 50cm did that moving at more than 2.2g, which was fast enough to throw people right off the ground and up into the air. 

Whether more of the city will have to be abandoned remains to be seen.

Posted by Drew458     on 03/07/2011 at 09:39 AM   
Filed Under: • International •  
• Comments (2) • Trackbacks(0)  Permalink •  

DISCLAIMER

THE SERVICES AND MATERIALS ON THIS WEBSITE ARE PROVIDED "AS IS" AND THE HOSTS OF THIS SITE EXPRESSLY DISCLAIMS ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, TO THE EXTENT PERMITTED BY LAW INCLUDING BUT NOT LIMITED TO WARRANTIES OF SATISFACTORY QUALITY, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO THE SERVICE OR ANY MATERIALS.

Not that very many people ever read this far down, but this blog was the creation of Allan Kelly and his friend Vilmar. Vilmar moved on to his own blog some time ago, and Allan ran this place alone until his sudden and unexpected death partway through 2006. We all miss him. A lot. Even though he is gone this site will always still be more than a little bit his. We who are left to carry on the BMEWS tradition owe him a great debt of gratitude, and we hope to be able to pay that back by following his last advice to us all:

1. Keep a firm grasp of Right and Wrong
2. Stay involved with government on every level and don't let those bastards get away with a thing
3. Use every legal means to defend yourself in the event of real internal trouble, and, most importantly:
4. Keep talking to each other, whether here or elsewhere

It's been a long strange trip without you Skipper, but thanks for pointing us in the right direction and giving us a swift kick in the behind to get us going. Keep lookin' down on us, will ya? Thanks.

THE INFORMATION AND OTHER CONTENTS OF THIS WEBSITE ARE DESIGNED TO COMPLY WITH THE LAWS OF THE UNITED STATES OF AMERICA. THIS WEBSITE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE UNITED STATES OF AMERICA AND ALL PARTIES IRREVOCABLY SUBMIT TO THE JURISDICTION OF THE AMERICAN COURTS. IF ANYTHING ON THIS WEBSITE IS CONSTRUED AS BEING CONTRARY TO THE LAWS APPLICABLE IN ANY OTHER COUNTRY, THEN THIS WEBSITE IS NOT INTENDED TO BE ACCESSED BY PERSONS FROM THAT COUNTRY AND ANY PERSONS WHO ARE SUBJECT TO SUCH LAWS SHALL NOT BE ENTITLED TO USE OUR SERVICES UNLESS THEY CAN SATISFY US THAT SUCH USE WOULD BE LAWFUL.

Copyright © 2004-2015 Domain Owner