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Zipingpu Dam May Have Triggered the Sichuan Quake
bfwebster writes "An article in the Telegraph (UK) raises an interesting question: was the massive (7.9) Sichuan earthquake that wracked China last year and left millions homeless caused by ground stresses following the completion of the Zipingpu dam? As the article notes, 'The 511-ft-high Zipingpu dam holds 315 million tonnes of water and lies just 550 yards from the fault line, and three miles from the epicenter, of the Sichuan earthquake. Now scientists in China and the United States believe the weight of water, and the effect of it penetrating into the rock, could have affected the pressure on the fault line underneath, possibly unleashing a chain of ruptures that led to the quake.'" The Sichuan region is earthquake-prone, but has not seen anything as large as the 7.9-magnitude quake for perhaps millions of years. The Chinese government denies any connection between the dam and the earthquake and seems to be actively obstructing the access of scientists who want to investigate. The article concludes, "There is a history of earthquakes triggered by dams, including several caused by the construction of the Hoover Dam in the US, but none of such a magnitude."
...earthquakes KILL you!
-=/\- Jizzbug -/\=-
Those dam quakes always screwing everything up!
- Your stupidity got you into this mess, why can't it get you out? -Will Rogers
As with all things geological, there are a lot of unknown variables, hence the "could", "might" and other diluting terms.
Engineering is the art of compromise.
Well, it's either have the earthquake now or have it later. Take your pick.
I feel a bad movie based on this where need to blow up dam to stop a super quake from happening is coming.
Chinese officials will conclude that the scientific findings are acurrate and convincing, will acknowledge that the dam did cause the quake, will apologize sincerely, and resign in disgrace. The replacements will then close down the dam, making sure to dismantle it in an ecologically sensible way, doing the least disruption to the surrounding communities as well, and every victim of the quake will be compensated accordingly. You know, much as it would happen here.
You really have to love government humility and responsibility.
This earthquake killed a lot of people and ruined the lives of countless others. That effect was disproportionate on the poor.
Perhaps desalination is the most socially responsible source of clean drinking water. Let's use clean nuke power and use it for massive desalination. Clean energy can solve the world's water crisis without killing poor people.
DAM
Haven't we known for 40 years now that injecting water into a fault can trigger a quake?
I've abandoned my search for truth; now I'm just looking for some useful delusions.
Sir Ranulph Fiennes (the famous arctic explorer, among other things) was actually kicked out of the SAS for destroying a dam using stolen explosives. You can google for more detailed accounts of the story, but here's one:
http://www.independent.co.uk/student/career-planning/getting-job/my-first-job-explorer-sir-ranulph-fiennes-was-an-sas-officer-420601.html
Convert FLACs to a portable format with FlacSquisher
let's say they know dams cause earthquakes. ok, so there will be some minor earthquakes. but 7.9? no one is going to predict anything that large
still, let's assume the dam is still the trigger for the 7.9 earthquake. emphasis on trigger. its going to happen someday anyway
if they never built the dam, we'd be talking about the 7.9 or 8.3 sichuan earthquake of 2031 or 2102
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Dear world governments and corporations,
It's not that I'm a naive left-winger or wack-job environmentalist or tree-hugging hippie or anything of that sort. But for crying out loud, have you not noticed a pattern here? No? Then I'll spell it out for you as bluntly as I know how:
When you fuck with nature, nature fucks with you.
Thank you,
Anonymous Coward
Proud Member of the Common Sense Brigade
Would a 7.9 quake, although large by earthquake standards, even leave evidence that lasted more than, say, 1000 years? You might be able to tell if you took a cross section of the entire fault line, I suppose, but not all fault lines are known. A L.A. city geologist found a previously unknown (but not currently active) fault under the house of a friend of mine when he was having some drainage work done; new ones are discovered all the time.
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
THere are billions of chinese left.
When you build on a fault line, nature is going to give you a big fucking shake sometime.
Building a dam nearby might bring the event forward a bit, but it's going to happen anyway.
Engineering is the art of compromise.
Just move along...
--I like turtles...
Triggering a quake by building such a huge dam is not cost-effective. The Chinese could have gotten the same quake for less money by getting everyone to climb up on a chair and jump at the same time.
like this one? http://www.youtube.com/watch?v=xHPikUPlRD8
That monumental earth-shattering project is much larger in scope. It is 315 miles from the Sichuan earthquake's epicenter but in any case, if this phenomenon is true perhaps it may not have been related to this earthquake but will wreak havoc one day. Of course, they can just keep denying anything and not worry about the dam impact.
The real interest here is that the dam survived the quake, right?
-fb Everything not expressly forbidden is now mandatory.
If this is true, then just wait until the Three Gorges begins to top off (it has been filling for years now and has some time to go.)
Why did this take so long to get into mainstream media? According to a well-hidden footnote on Wikipedia it was in Science on January 16. I read about it a week ago in a German newspaper.
hehehe zipping poo hehehe
Hahahaha - Zipping Poo... Best name for a dam ever!
No dam for you!
$ make available
Not sure that I would want to be located downstream from a chinese built dam.
I prefer the "u" in honour as it seems to be missing these days.
Did anyone else read that as Zipping Poo Dam?
that if we reomve a dam, as many people think we should do, would that also precipitate an earthquake? After all, we'd be changing the stresses on the fault.
Fascinating subject; I never knew before this that a dam could actually cause an earthquake. Makes sense when you think about it but I never thought about it since I've had little to do with dams aside from getting most of my power from them.
You know the thing about UDP jokes? I don't care if you get it or not.
Maybe they can get this drilling crew on the mission to save the day!
All humour aside, most people have no clue about the energy levels and destructive power available to natural forces, just on our world. (ie:water) Even engineers can fall prey to their preconceptions at times, if they are not diligent. Water is a powerful force, in scale.
Most people perceive the Earth as a solid/stable surface to build on(dig to 'bedrock' for the foundation, etc...), frequently forgetting Earth more resembles a poultry egg: relatively thin shell covering/encasing a liquid center...and just as fragile on scale.
At our most terrible destructive level available technologically to humans today, we are still just 'wannabe' punks in the big picture. Actually, I would argue that communication tech is the most powerful weapon/tech we have devised to date.
*(IAANB) I Am A NASA Brat![clarification of subject line]-just could not pass this one up. And NOT trying to pick on engineers, who have demanding job requirements, but there is a good reason to put erasers on pencils! :-)
Sorry if this was more than you bargained for trying to make a 'funny', but you did raise a valid point! :-)
Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
Oh yeah, only Jackie Chan and Jet Li can save us now. Sounds like Kung Fu gold.
We hope your rules and wisdom choke you / Now we are one in everlasting peace
Yes but records only go back for a few thousand years, when the hall of records was mysteriously destroyed somehow.
(with apologies to the Simpsons)
If adding tons of water within days is enough to threaten the stability of a fault, obviously removing tons of water within minutes is the safest way to fix the problem. Yes, I can see the movie industry (which once depicted people being pursued by cold air) falling for that.
Well, it's a Wonderful thing We've never Witnessed a gov't like that in the USA. Knock on Wood.
Table-ized A.I.
I purchased some of those pounds of which you speak with USD, this past summer. It had an impact on my wallet, I assure you.
Good day!
This issue is a bit more complicated than you think.
Paleoseismology as you described is actually quite difficult. In the case of the San Andreas, you can't really look at off-set streams and such. You can rarely discern more than one or two events along such offsets, and once you do, it is very difficult to determine the age of the offset. You can get the amount that it's moved, yes, but not the timing. Worse, since you don't know the timing, you don't know if the offset is from one or more events.
The way it's done for strike-slip faults like the San Andreas is to look at a cross-section perpendicular to the fault, looking for layers of material off-set (or suddenly changing thickness, etc.) along the fault. The best way to date those layers is through carbon-14 dating of organic material, which can give you accuracy only within ~1-200 years - and that's assuming that the organic material you date is not from elsewhere, is not from 200 year old trees, etc. If an event offsets every layer from the bottom up to a certain point, you date the top layer that it cuts through to get a maximum age, and the layer that it didn't cut through is the minimum age.
You can imagine the difficulty and ambiguous nature of this. The individual layers that you have to recognize and date are on the scale of centimeters to decimeters - I've seen some of the areas that were used, the famous one being along Pallet Creek which is along the San Andreas northeast of LA (I have a picture of it - well, it is a picture of a girl standing in front of it - here: http://www.flickr.com/photos/penguinchris/3037578910/) Here, luckily there was constant, relatively rapid deposition of material. In most places this is not the case, so any record of movement on the fault is eroded away.
For the San Andreas, we have a partial record going back ~1500 years. There really is no reliable way to reach back further than that - the record isn't normally visible in older rock units. Looking at the larger-scale structures is interesting by itself but doesn't tell you anything about when specifically there was movement. The fault system in the Sichuan region is fairly well understood - it is a kind of combination strike-slip/thrust fault (see http://quake.mit.edu/~changli/wenchuan.html for some nice diagrams.) But I want to call BS on the idea that they have any idea how frequently major earthquakes have happened there - and even if they do, the idea that it is "perhaps millions of years" since the last one is ridiculous no matter what.
And then, when you *do* figure out a approximate year for an earthquake, how do you determine how big it was? Again, extremely difficult! The best estimates come from comparing old written records of destruction with those from modern earthquakes - nothing scientific at all!
What's being done extensively with the San Andreas is physics-based computer modeling - we have some idea of the force building up, and combining that with records of historical earthquakes we can make an estimate of a major earthquake every ~150 years. But even for this, the best-studied earthquake area, it's not much more than a guess.
I don't know as much about the Teton fault (other than that it is a normal fault, not a thrust fault as you stated ;) ) but I'll comment on the idea of a "magnitude 7 earthquake every 400-700 years." These kinds of estimates are based on the very difficult work I described earlier (and I'm not sure how much has been done for the Teton fault) and whatever geologist came up with that would probably admit it is a simple guess without much to base it on. I mean, think of it - is knowing there's a large earthquake every 400-700 years really all that useful anyway?
By the way, I assume any dating of the Teton fault would be done this way: when new patches of rock are exposed along the fault as you described, they start getting hit by cosmogenic radiation. By measuring the amount of cosmogenic radio isoto
The article and summary are misleading to the extent that they talk about the "weight of water" possibly causing the quake. The scientists involved also, almost certainly, do not suspect the weight of the water, as such, was the cause.
The weight of water was utterly irrelevant compared to the weight of the rock beneath and around the dam and the fault. Water has a density of about 1 gram per cubic centimeter. Common crustal rock (usually) has a density in the vicinity of 2.7 grams per cubic centimeter, and there's a hell of a lot more rock than water; remember the earthquake occurred at a depth of twelve miles. The simple added weight would not be noticeable at depth.
What may have happened, as it is the mechanism by which dams may cause earthquakes, is pooling a large amount of water in the vicinity of the fault may have changed the pore fluid pressure in the rock. The increase in pore fluid pressure would have the effect of reducing the net confining pressure on the fault, while the differential stress remained the same, allowing the fault to slip more easily.
The easiest way to think about this is to imagine the pressure the rock had been exerting in all directions to lock the fault together -- to keep it from moving. There's some component of stress that is pushing the two sides of the fault in different directions, but the rock is being squeezed too tightly to move.
Now when more (incompressible) water is added to the system the differential stress remains the same, but the effective pressure locking the fault in place is reduced on account of the higher water pressure in the rock's pore spaces. The shear stress may then be great enough to allow the fault to slip, causing an earthquake.
I have no idea whether this was a factor in this particular earthquake, but it has caused earthquakes ranging from unnoticeable to more significant in other parts of the world, even in tectonically quiet regions. For example, the water level in the Aswan High Dam is supposedly correlated with minor background seismic activity.
\addbot anarki 5
I feel a bad movie based on this where need to blow up dam to stop a super quake from happening is coming.
A super-flood to stop a super-quake?
Eclipse PDE and Me
It could indeed have helped. There was a proposal a few years ago to inject water into faults, the idea being that this would lubricate the faults and trigger quakes sooner. That, of course, means more smaller quakes, rather than fewer really big ones.
You do realize that first in the series of quakes thus facilitated would potentially be a really big one (unless injecting water starts right after the last big "dry" one), don't you?
Of these muthafuckin' QUAKES on this muthafuckin' (fault)PLANE!!!
"When information is power, privacy is freedom" - Jah-Wren Ryel
by ensuring that instead of being released by four 5.6 earquakes, it was released all in one go. For the bungee-cord analogy, if you LET GO for a bit, the bungee cord will jump more quickly and cover more ground than if your grip just wasn't really enough. If you'd kept hold it might slip, stop, slip, stop several times but never, since you had SOME tension on the cord, reach the speed and acceleration of the scenario where you let go.
Every natural disaster has a disproportionate effect on the poor!,
Not avalanches. ;-)
I'm have doubts about waterspouts, too.
Of course, these exceptions just prove your rule.
Who really gives a dam?
About 20 years ago a US Geological Survey scientist noted the associated of several large California earthquakes and large oil production. He cited the same principles as in the this dam case and showed some calculations. But its hard to rule out other factors and prove this conclusively.
The 511-ft-high Zipingpu dam holds 315 million tonnes of water and lies just 550 yards from the fault line
China (and by the way the rest of the world except USA, Burma and Liberia) uses the metric system. Your numbers sound like chinese to me and most of the world population.
There are a lot of earthquakes in Japan, perhaps these were caused by the 2 atomic bombs that made the land more vulnerable?
*sarcasm off*
Or not.
Do some science and get an answer to the question.
There is no "-1 offended" or "-1 you don't agree with me" mod options for a reason.
Look, if one person attacks each grammar/spelling mistake, this is gonna take all day. Do it in one post or don't do it at all.
Everyone we will be stageing passengers to board the flood plane shortly. There will be free items given away on board as there has been a store surge. Takeoff may be delayed since the runway lights where whipped out by an insane Indiana Jones fan earlier. They typical job of replacing them doesn't take long, but the workshop doors are frozen shut and it may take some time to get the service truck out side. What is the good part. You will all be in Hawaii in just a few hours!!!!!
(Good post LWATCDR, but you left yourself wide open :P)
"When information is power, privacy is freedom" - Jah-Wren Ryel