7.0 earthquake hits Christchurch, New Zealand

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Discussion Overview

The discussion revolves around the 7.0 earthquake that hit Christchurch, New Zealand, focusing on the immediate impacts, personal experiences, and the broader implications of the event, including political aspects and community responses. Participants share their thoughts on the nature of natural disasters and their societal effects, as well as personal anecdotes related to the quake.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants note that natural disasters often become political issues, questioning the appropriateness of discussing such topics in the forum.
  • There are mixed feelings about the level of debate that can arise from the earthquake, with some expressing skepticism about the potential for meaningful discussion.
  • Personal accounts of experiencing the earthquake highlight varying degrees of damage and emotional responses, with one participant describing significant aftershocks and infrastructure damage.
  • Concerns about looting were raised, with some participants downplaying the extent of the issue and emphasizing the disciplined response of the community.
  • Participants discuss the structural integrity of buildings, contrasting wood and concrete construction, and how these materials perform during earthquakes.
  • There is mention of the historical context of earthquakes in New Zealand, including the potential for more severe quakes in the future.
  • Some participants express gratitude for the lack of fatalities, while acknowledging the significant financial costs associated with the damage.
  • Discussion includes reflections on the effectiveness of civil defense responses and community preparedness for such disasters.

Areas of Agreement / Disagreement

Participants generally agree on the absence of fatalities being a positive outcome, but there are multiple competing views regarding the political implications of the disaster and the adequacy of community responses. The discussion remains unresolved on several points, particularly regarding the nature of the debate and the extent of damage and looting.

Contextual Notes

Participants express uncertainty about the long-term implications of the earthquake, including potential future seismic activity and the effectiveness of current building codes and preparedness measures. There is also a lack of consensus on the characterization of the community's response to the disaster.

  • #61
apeiron said:
Thanks for people's concerns. Power has been off so no net access. Plus there is stuff to do. :smile:

Summary is me and mine are basically fine, there will be a few hundred dead, which looking around at the buildings that went, could be considered lucky, and rebuilding sewers, economy, homes, will be something we are still talking about in 5, probably 10 years.

It was incredibly bad luck to get a second shallower and almost right under the city. A mag 6 was expected following a mag 7, the hope was that it would be further away.

Here is the quick update I've been sending friends.

-------------------------

Hi - Family, house and cats all fine. We are in the lucky part of town where the damage is the least. We have water but not yet power. No visible damage at all really in our suburb. But a lot of the town is properly devastated this time round.

I was in the central city at the time and we had one person killed, several trapped, as a fair bit of our historic building collapsed. I was under a desk watching bits of ceiling fall in and bricks from the top floor rain down.

Sandy was at her clinic across town and her problem was that pipes broke, ground liquified, so in minutes her car was swamped and had to be abandoned. She got a lift home from a bus driver who abandoned his route to bring her to the door.

Kids were just finishing lunchbreak, so were safely outside.

The problems now are lack of power (so we have been out of communication with the world - I am typing this from our printing press on the outskirts of town where I can get a powerpoint and internet connection). The sewers are stuffed, so we shouldn't be using toilets (but with water going, most people still are). We have not had to go down to shops as we have a freezer of stuff going off, plus a vast supply of pasta/tinned tomatoes and other earthquake basics. But actually, food and fuel can get into Christchurch pretty easily, so no fear there.

Law and order not a problem, and everyone is helping neighbours. We have been looking after the oldies down our street, who need reassurance as much as anything.

Longer term, the town is looking to be in for a very hard time economically as the central business district looks inoperable for months and the fixing of roads, sewers, electricity will take years (they will be patched up in weeks, but rebuilding will go on a long time).

----------------------

Phew... I'm glad you and all are well, I'm sorry about everything else though.
 
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  • #62
turbo-1 said:
apeiron, glad to hear that you and yours are OK.

When I saw the fist images of the pancaked buildings and collapsed walls, my first thought was that deaths would probably total in the low thousands, not the hundreds. I'm very happy to be wrong on that count.

News is coming out that you might be right... I'm very glad to have heard from apeiron given that news.

CNN-"Death toll expected to rise sharply"
 
  • #63
turbo-1 said:
apeiron, glad to hear that you and yours are OK.

When I saw the fist images of the pancaked buildings and collapsed walls, my first thought was that deaths would probably total in the low thousands, not the hundreds. I'm very happy to be wrong on that count.

Yeah, the TV cameras pick out the worst. Two tall buildings did collapse dramatically. Possibly due to lateral spreading as liquified land slumped towards the river. A lot of frontages fell down, squashing buses and people, but building codes mean that most places were wrecked yet not collapsed. People could get out.

The serious stuff is what earthquakes do to services underground. Pretty much a whole town sewer and water system to be dug out and relaid.

@ evo: not so much terrifying as just really annoying. The town was well along in its recovery from the first quake. So a second hit is psychologically a big drain.
 
  • #64
apeiron said:
Yeah, the TV cameras pick out the worst. Two tall buildings did collapse dramatically. Possibly due to lateral spreading as liquified land slumped towards the river. A lot of frontages fell down, squashing buses and people, but building codes mean that most places were wrecked yet not collapsed. People could get out.

The serious stuff is what earthquakes do to services underground. Pretty much a whole town sewer and water system to be dug out and relaid.

@ evo: not so much terrifying as just really annoying. The town was well along in its recovery from the first quake. So a second hit is psychologically a big drain.

That's for the future, for now the best thing is to aknowledge that future, but live in the moment. It may be that there is some good to come of this; in fact one theory is that these multiple quakes are taking the place of a "Big One".
 
  • #65
The Pyne Gould Guinness Building, a multi-storey building containing more than 200 workers, has collapsed and an unknown number of people are trapped inside.
That was half-collapsed.

The CTV building completely collapsed.

http://www.telegraph.co.uk/news/worldnews/australiaandthepacific/newzealand/8340203/Christchurch-earthquake-destruction-seen-from-the-air.html

http://www.telegraph.co.uk/news/worldnews/australiaandthepacific/newzealand/8339930/Powerful-earthquake-devastates-Christchurch.html
 
  • #66
nismaratwork said:
That's for the future, for now the best thing is to aknowledge that future, but live in the moment. It may be that there is some good to come of this; in fact one theory is that these multiple quakes are taking the place of a "Big One".

Wrong theory. The Alpine fault where the plates actually grind past each other is still waiting to go (about once every 600 years). These are just lateral faults that run all the way up the eastern coastline. The alpine would be 8+. And about as damaging as current quakes here, because it would be over 100km away. But bad for other cities and towns right in the path.

Many cities have rebuilt quite well out of quakes, so the 20 year view is more optimistic. At least now we can say that two of our big local faults have gone and it should take another 20,000 years or so for them to reload. It seems unlikely there can be more lurking so close to town. But hopefully we will be doing full seismic surveys to discover that.
 
  • #67
Yay...so good to hear from you, apeiron! Glad everything is well with your family and cats.
 
  • #68
lisab said:
Yay...so good to hear from you, apeiron! Glad everything is well with your family and cats.

The cats are now happy in the sunshine. Power is back on but they are getting fat on defrosting scallops and prawns that would otherwise go in the bin.

Whoops, just then another aftershock. One thing the news never explains is that we were still getting little bumps several times a day five months after the first quake.

Someone put together this time lapse animation of the many thousands we've had.

http://www.christchurchquakemap.co.nz/
 
  • #69
It's good to hear from you and your cats again :smile:
 
  • #70
apeiron said:
The cats are now happy in the sunshine. Power is back on but they are getting fat on defrosting scallops and prawns that would otherwise go in the bin.

Whoops, just then another aftershock. One thing the news never explains is that we were still getting little bumps several times a day five months after the first quake.

Someone put together this time lapse animation of the many thousands we've had.

http://www.christchurchquakemap.co.nz/

Wow, that's an interesting animation. I didn't look at all of it but it seemed unusually quiet before Tuesday's big one.
 
  • #71
It is important to pay attention to activity in the region encompassing Vanuatu, Fiji, Tonga, Kermadec Islands as well as NZ. They are part of the same system.

Seismic activity around Christchurch. The Canterbury area is an outlier for big ones.
http://neic.usgs.gov/neis/bulletin/neic_b0001iiu_l.html
http://neic.usgs.gov/neis/bulletin/neic_b0001iiu_h.html

Also pay attention to changes under Akaroa and Lyttelton.

The activity under Lyttelton is interesting. It stopped abruptly. Correction: it's filtered for > 4mag
Code: 
         UTC DATE-TIME        LAT    LON
MAG     y/ m/d   h: m:s       deg    deg    DEPTH km    
4.2  2011/02/22 17:00:19   -43.613 172.814   8.4  
4.0  2011/02/22 14:30:13   -43.634 172.819  13.4  
4.3  2011/02/22 14:04:36   -43.614 172.875  10.0  
4.5  2011/02/22 11:02:16   -43.548 172.779   5.0  
4.8  2011/02/22 08:21:06   -43.599 172.560   6.9  
4.5  2011/02/22 06:43:30   -43.593 172.859   5.0  
4.4  2011/02/22 06:28:31   -43.590 172.710   5.0  
4.3  2011/02/22 05:59:35   -43.640 172.770   5.0  
4.1  2011/02/22 04:19:05   -43.600 172.750  15.0  
4.4  2011/02/22 03:04:09   -43.570 172.650  12.0  
5.5  2011/02/22 01:50:29   -43.588 172.734   9.6  
5.6  2011/02/22 00:04:18   -43.580 172.798   6.7  
6.3  2011/02/21 23:51:43   -43.600 172.710   5.0
 
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  • #72
apeiron said:
Wrong theory. The Alpine fault where the plates actually grind past each other is still waiting to go (about once every 600 years). These are just lateral faults that run all the way up the eastern coastline. The alpine would be 8+. And about as damaging as current quakes here, because it would be over 100km away. But bad for other cities and towns right in the path.

Many cities have rebuilt quite well out of quakes, so the 20 year view is more optimistic. At least now we can say that two of our big local faults have gone and it should take another 20,000 years or so for them to reload. It seems unlikely there can be more lurking so close to town. But hopefully we will be doing full seismic surveys to discover that.

I admit, I was reaching... you're too smart for your own good and comfort! :wink:

Again, I'm very glad you and your's well.
 
  • #73
Good to hear apeiron, apeiron's family and cats, and Dadface's family are safe.
 
  • #74
Wow, glad to hear that you survived (with just a scare) and everyone in your family including your pets are safe, I lived through 2 quakes in San Diego in the late 70's and early 80's. They are disconcerting and frightening to say the least. Has the damage affected your ability to get to and from work, and your work place, at least for the short term ?

Rhody...
 
  • #75
apeiron, good to hear everyone is ok.
 
  • #76
rhody said:
Has the damage affected your ability to get to and from work, and your work place, at least for the short term ?

My workplace is semi-collapsed and will be demolished I'm sure. Ironically, we were due to move into a brand new building next week. That survives but with many windows gone and other damage. Besides, central city will be out of bounds for a month I would say.

We have a 20 story hotel that is leaning into a hole that opened up under a corner. That has to come down somehow. Whole city blocks will be bulldozed.

But I write for the city paper. And we got an edition out the next morning. You'd be surprised at how people can cope. Especially with all the help that comes in from outside.
 
  • #78
apeiron said:
My workplace is semi-collapsed and will be demolished I'm sure. Ironically, we were due to move into a brand new building next week. That survives but with many windows gone and other damage. Besides, central city will be out of bounds for a month I would say.

We have a 20 story hotel that is leaning into a hole that opened up under a corner. That has to come down somehow. Whole city blocks will be bulldozed.

But I write for the city paper. And we got an edition out the next morning. You'd be surprised at how people can cope. Especially with all the help that comes in from outside.

Wow, I can't even imagine what that must be like! It could take many years to recover, from the sounds of it.
 
  • #79
I finally got word from a relative. Ironically, their house was being inspected by a representative from the Earthquake Commission when the earthquake struck. They live near Lyttleton. Needless to say, they have more damage.

They are visiting family up north and will be back early next week to help with ongoing efforts.


Someone snapped this picture seconds after the earthquake
http://www.redditpics.com/christchurch-panorama-seconds-after-earthquake,11249/

At least 1/3, and maybe up to 2/3, of the buildings in the central business district are damaged.
http://www.3news.co.nz/Christchurchs-heart-ripped-to-bits/tabid/369/articleID/200008/Default.aspx



A close friend has family in CC. Everyone is OK.
 
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  • #80
Good to hear your rellatives and your friend's rellatives are ok. I'm sorry to hear of all the damage, of course.
 
  • #81
aperion,
My workplace is semi-collapsed and will be demolished I'm sure. Ironically, we were due to move into a brand new building next week. That survives but with many windows gone and other damage. Besides, central city will be out of bounds for a month I would say.

I just looked at a few of Astronuc's links, the heart of the quake was essentially right under the center of downtown ? Holy ..., it sounds like you sort of lucked out, as you mention moving to a brand new work place next week. I am sure it is very unsettling. I only speak for myself, but you seem to be holding up remarkably well considering all you and you family and community have been through. I don't know what else to say except that in print on PF you seem remarkably calm and composed, if it were me, I assure you that would not be the case.

Rhody... o:)
 
  • #82
I heard one official mention the cost of rebuilding the infrastructure being as much as $30 billion.

There is a picture that shows the distribution of earthquakes before and since Feb 22. Clearly the earthquake occurences have been shifting eastward (and westward) during the last several months.
http://www.geonet.org.nz/news/feb-2011-christchurch-badly-damaged-by-magnitude-6-3-earthquake.html

The acceleration at one station was revised to 2.2g, which is a very significant acceleration.
 
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  • #83
This is an excellent graphic illustrating the location of the two quakes (the second in red is clearly right under the town) and just how many aftershocks there have been.

http://www.geonet.org.nz/var/storage/images/media/images/news/2011/lyttelton/57171-1-eng-GB/Lyttelton.jpg
 
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  • #84
If one checks Paul Nicholls's earthquake map, one sees in the two hours following the mag 6.3, there were two others at mag 5.7 and 5.9, punctuated by several in the 3 - <5 range.
6.3M, depth: 5km 12:51
4.9M, depth: 5km 12:56
5.7M, depth: 7km 13:04
4.2M, depth: 9km 13:21
4.4M, depth: 7km 13:23
4.2M, depth: 9km 13:31
4.5M, depth: 5km 13:46
4.5M, depth: 5km 14:15
4.5M, depth: 4km 14:20
3.4M, depth: 5km 14:30
3.3M, depth: 5km 14:37
4.0M, depth: 8km 14:39
5.9M, depth: 7km 14:50

And there have been many more since.

The liquefaction of the ground was considerable more severe with the Lyttelton earthquake than with the Darfield quake which was further away and deeper.
 
  • #85
apeiron said:
This is an excellent graphic illustrating the location of the two quakes (the second in red is clearly right under the town) and just how many aftershocks there have been.

http://www.geonet.org.nz/var/storage/images/media/images/news/2011/lyttelton/57171-1-eng-GB/Lyttelton.jpg

Stay strong apeiron, and again... I'm really glad that you and dadface are alive and whole, with families in similar condition.
 
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  • #86
Astronuc, aperion,

I am no geologist or expert in seismology, however, the thumbnail below taken from the links you both provided reminds me of a zipper, a buried one that is slowly rising to the surface as it heads toward the ocean.

Rhody...
 

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  • #87
rhody said:
Astronuc, aperion,

I am no geologist or expert in seismology, however, the thumbnail below taken from the links you both provided reminds me of a zipper, a buried one that is slowly rising to the surface as it heads toward the ocean.

Rhody...

Make that a sticky zipper, and I think you're closer to the truth than you may know!
 
  • #88
rhody said:
Astronuc, aperion,

I am no geologist or expert in seismology, however, the thumbnail below taken from the links you both provided reminds me of a zipper, a buried one that is slowly rising to the surface as it heads toward the ocean.

Rhody...
There appear to be a series of east-west faults, which are a consequence of the those two old (ostensibly extinct) volcanos and the mountains. The Canterbury plains are alluvial deposits having been deposited from the erosion of the mountains to the west.

I think they will have to rethink the seismic hazard in that area.

Some of the day recorded.



 
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  • #89
Astronuc said:
There appear to be a series of east-west faults, which are a consequence of the those two old (ostensibly extinct) volcanos and the mountains. The Canterbury plains are alluvial deposits having been deposited from the erosion of the mountains to the west.

I think they will have to rethink the seismic hazard in that area.

Some of the day recorded.





When you say things like "ostensibly extinct", you give me agita! :wink:

Kidding aside, thanks for an excellent explanation, and... liquifaction is not something you can defend against AFAIK. You can put a building on rockers or springs. make it bend like a willow, but if the foundation goes... game over. You may be able to prevent catastrophic collapse (NZ versus Haiti), but the structure will still need to be destroyed and rebuilt.

I feel terrible for (and I say this affectionately) all Kiwis, feathered and mammalian. NZ seems like such a peaceful and welcoming place... :frown:
 
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  • #90
Astronuc said:
There appear to be a series of east-west faults, which are a consequence of the those two old (ostensibly extinct) volcanos and the mountains. The Canterbury plains are alluvial deposits having been deposited from the erosion of the mountains to the west.

I think they will have to rethink the seismic hazard in that area.

Some of the day recorded.





Astronuc,

That was absolutely horrifying to watch, I only could watch about 2/3rds of the first video, at about 1:30 or so a woman in a black dress with head injuries was being led away. I found out later she lost her brother who was sitting in a car next to her, he pushed her away and saved her life. The video news story was so sad. it all seems so surreal.

Rhody...
 
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