earthquake in Sichuan Province, China

[amberjack1234]

This is an update on the earthquake in Sichuan that I found interesting.

 

Larry

 

 

http://www.nytimes.com/2009/02/06/world/asia/06quake.html

 

BEIJING ¡ª Nearly nine months after a devastating earthquake in Sichuan Province, China, left 80,000 people dead or missing, a growing number of American and Chinese scientists are suggesting that the calamity was triggered by a four-year-old reservoir built close to the earthquake¡¯s geological fault line.

 

A Columbia University scientist who studied the quake has said that it may have been triggered by the weight of 320 million tons of water in the Zipingpu Reservoir less than a mile from a well-known major fault. His conclusions, presented to the American Geophysical Union in December, coincide with a new finding by Chinese geophysicists that the dam caused significant seismic changes before the earthquake.

 

Scientists emphasize that the link between the dam and the failure of the fault has not been conclusively proved, and that even if the dam acted as a trigger, it would only have hastened a quake that would have occurred at some point.

 

Nonetheless, any suggestion that a government project played a role in one of the biggest natural disasters in recent Chinese history is likely to be politically explosive.

 

The issue of government accountability and responsiveness has boiled over in China in the past year. The grieving parents of thousands of schoolchildren killed in the disaster have already made the 7.9-magnitude earthquake a political issue, charging that children died needlessly in unsafe school buildings approved by negligent or corrupt officials.

 

More public anger erupted last year when the government failed to prevent the sale of tainted milk powder that sickened nearly 300,000 children and killed six.

 

¡°Any kind of government-related disaster presently is very, very damaging and politically extremely sensitive,¡± said Cheng Li, the China research director at the Brookings Institution.

 

If it is proved that the earthquake ¡°was related to a man-made situation and not just a natural disaster, the government will be very uncomfortable with that kind of report because of the whole issue of government accountability,¡± Mr. Li said.

 

Questions about the Zipingpu Dam are especially delicate because China is building many major hydroelectric dams in the southwest, a region which has abundant water resources but is considered prone to earthquakes.

 

In a petition to the government in July, a group of environmentalists and scholars said the fact that government scientists had underestimated the risk of the May earthquake raised questions about a host of other dams built in the same valley and along five other major rivers, according to an article published by Probe International, an environmental advocacy group. Chinese authorities have steadfastly dismissed any notion that reservoir-building in Sichuan Province placed citizens at any added risk, and they have blocked some Web sites of environmental groups that suggest that dangers have been overlooked.

 

In a December article in the Chinese magazine Science Times, two scientists from the Chinese Academy of Sciences strongly denied that the dam played any role in the earthquake. ¡°The earthquake research community outside and inside China has widely accepted the notion that the May 12 Wenchuan earthquake was a huge natural disaster caused by massive crustal movement, because no reservoir triggered-quake with a magnitude eight has ever occurred in history,¡± said Pan Jiazheng, an expert in hydroengineering, according to a translation published by Probe International.

 

Scientists generally agree that a reservoir, no matter how big, cannot by itself cause an earthquake. But Leonardo Seeber, a senior scientist with the Lamont-Doherty Earth Observatory of Columbia University, said the impact of so much water could hasten an earthquake¡¯s occurrence if geological conditions for a quake already existed. He said the best known example was a 1967 earthquake triggered by the Koyna Dam in a remote area of India, with a magnitude of about 6.5 and a death toll of about 180 people.

 

Mr. Seeber said that while the link between the Sichuan earthquake and the Zipingpu Dam was not yet proved, work by Christian Klose, a Columbia University researcher specializing in geophysical hazards, suggested the stress caused by the water¡¯s weight might have hastened the quake by a few hundred years.

 

¡°It would have occurred anyway,¡± Mr. Seeber said. ¡°But of course the people who were affected might think the timing is an important difference.¡±

 

Mr. Klose estimated that the weight of the water in the Zipingpu reservoir amounted to 25 times the natural stress that tectonic movements exert in a year. The added pressure, he wrote in an abstract to an unpublished study, ¡°resulted in the Beichaun fault coming close to failure.¡±

 

Fifty stories tall and big enough to hold more than one billion cubic meters of water, the Zipingpu Dam astride the Minjiang River was billed as one of China¡¯s biggest water control projects.

 

Officials said the $750 million project, part of a grand plan to develop regions in China¡¯s south and west, would generate 760,000 kilowatts of electricity, irrigate more farmland, help control flooding and provide more water to industries and residents of nearby Chengdu, a city of more than 10 million.

 

Almost as soon as construction got under way in 2001, one expert, Li Youcai, voiced fears that officials were underplaying the risk of a major earthquake in the region, but government officials rejected his argument, according to an article published last year on China Dialogue, a Web site devoted to environmental news.

 

Officials allowed the reservoir to fill with water in late 2004. Fan Xiao, a chief engineer with the Sichuan Geology and Mineral Bureau, said that from late 2004 to late 2005, the data showed 730 minor earthquakes, with magnitudes of 3 or less.

 

When the major earthquake struck last May, it originated 3.4 miles from the reservoir. The rupture in the Earth¡¯s crust stretched for 185 miles, initially moving in a direction that Mr. Klose said was consistent with the pressure from the water¡¯s weight.

 

Mr. Fan, the chief engineer for the regional geology investigation team, told reporters soon afterward that he believed that the reservoir influenced the timing, magnitude and location of the earthquake.

 

¡°The main lesson is that in building these kinds of projects we need to give more consideration to scientific planning and not simply consider the electricity or water or the economic interests,¡± Mr. Fan said.

 

The debate reignited in December when two scientists with the China Earthquake Administration and three other researchers published a study in the Chinese journal Seismology and Geology. They concluded only that the weight of the reservoir¡¯s water and diffusion of water from the reservoir below the Earth¡¯s surface ¡°clearly affected the local seismicity¡± over a period of nearly four years before the fault ruptured.

 

The Chinese researchers called for further study to see whether the reservoir helped trigger the earthquake. One of them, Du Fang, with the Sichuan Earthquake Administration, said Thursday that it was impossible to know whether the reservoir influenced the earthquake without more research. ¡°The possibility exists,¡± she said.

 

Ms. Du said she and other scientists were free to research the issue fully. ¡°We scientists are free to research the topic we proposed, as long as it is worth studying,¡± she said. ¡°I don¡¯t feel any restrictions on access to the data from the government.¡±

[Richard & Li]

I'm always skeptical of articles of this nature. I have been accused of being 'over-sensitive' to 'China bashing' in CFL, so I'll be concise.

 

These speculations are based on wild conjecture. If the point was to establish a scientific theory, it would not have been printed. The disclaimer "Scientists generally agree that a reservoir, no matter how big, cannot by itself cause an earthquake." can be found in the middle of the article.

 

If the article was about a real probable cause of earthquakes, why is the 'Tainted Milk Scandal" referred to in the middle of this article?

 

The fact is this: The Chinese government and people responded to this disaster at a speed and efficiency that should truly embarrass America after the way we handled the hurricane Katrina disaster.

 

This is a desperate attempt at turning the accolades deserved for heroic effort, compassion and real disaster relief into blame for causing the disaster. Ridiculous!!!

[amberjack1234]

I'm always skeptical of articles of this nature. I have been accused of being 'over-sensitive' to 'China bashing' in CFL, so I'll be concise.

 

These speculations are based on wild conjecture. If the point was to establish a scientific theory, it would not have been printed. The disclaimer "Scientists generally agree that a reservoir, no matter how big, cannot by itself cause an earthquake." can be found in the middle of the article.

 

If the article was about a real probable cause of earthquakes, why is the 'Tainted Milk Scandal" referred to in the middle of this article?

 

The fact is this: The Chinese government and people responded to this disaster at a speed and efficiency that should truly embarrass America after the way we handled the hurricane Katrina disaster.

 

This is a desperate attempt at turning the accolades deserved for heroic effort, compassion and real disaster relief into blame for causing the disaster. Ridiculous!!!

Yes, you said it Richard it does indeed seem that you are a little over sensitive in this area. I presented this article as a followup not a controversial issue about bashing China or America.

 

Larry

[Richard & Li]

Larry, I wasn't criticizing you. It was all about the content of the article.

 

You said you found the article interesting. So, did I. But, I strongly disagree with it and explained why.

[amberjack1234]

Larry, I wasn't criticizing you. It was all about the content of the article.

 

You said you found the article interesting. So, did I. But, I strongly disagree with it and explained why.

I'll buy that Richard.

 

Larry

[Richard & Li]

I guess I should also explain why I'm perhaps a bit over-sensitive about this particular topic.

 

I was in China when the earthquake occurred. I have family members in Chengdu some of them are police officers and were directly involved in the relief efforts. I saw the compassion of the Chinese people in person.

 

Li & I were only days from a planned vacation in Jiuzhaigou, where we might have had serious problems if the earthquake had been a few days later.

[amberjack1234]

Anyone may feel free to post as they please. I just don't want it to become a bashing contest.

 

Larry

[lostinblue]

http://www.johnmartin.com/earthquakes/eqpapers/00000054.htm

Reservoir-induced seismicity is considered to have occurred at four California sites. The four reservoirs and the largest triggered earthquake associated with each one are: Lake Mendocino in Mendocino County, M 5.2 (see CALIFORNIA GEOLOGY, December 1978, p. 275-281); Lake Crowley in Mono County, M 6.0 (see CDMG Special Report 150, p. 92-94); Lake Oroville in Butte County, M 5.7 (see CALIFORNIA GEOLOGY, June 1982, p. 115-118); and Lake Shasta in Shasta County, M <3.

 

 

CDMG is currently investigating seismicity at Lake Oroville. The seismicity at this location apparently is influenced or controlled by the seasonal variations in reservoir water storage, as indicated in the June 1982 issue of CALIFORNIA GEOLOGY . . . editor.

 

 

In numerous parts of the world today, including some of the most highly developed countries, many dam designers and operators have tended to close their eyes to the engineering problems posed by reservoir-induced earthquakes. One sometimes hears these kinds of defensive arguments: (1) no convincing correlation has yet been demonstrated between earthquakes and reservoirs; (2) since the natural seismicity at a given site is low, the danger of reservoir-inducement is therefore also low; (3) the geology at a given site is different from that at localities where major reservoir-induced events have occurred; (4) only three or four out of some 11,000 large dams worldwide have experienced significant induced earthquakes, and one should therefore not worry about a given site; and (5) no dam has yet failed disastrously because of a reservoir-induced earthquake, and the danger is thus grossly exaggerated. While many of these arguments have some elements of truth to them, they are essentially evading the primary issues: Virtually every careful study has concluded that there is indeed a cause-and-effect relationship between some earthquakes and some reservoirs, and two dams (Koyna, India, and Hsinfengkiang, China) have in fact come uncomfortably close to disastrous failure during such events. Furthermore, it is precisely in the regions of low natural seismicity where the major existing problems lie, because in areas of high seismicity dams are usually designed for substantial earthquake resistance anyway.

 

 

The unhappy current state of affairs is that our degree of understanding of reservoir-induced earthquakes is so minimal that almost no new reservoir anywhere in the world can be declared free of this possible danger. In particular, we do not know why such earthquakes occur, and we cannot as yet recognize with confidence those areas where reservoir-induced earthquakes are more likely than at other localities. It is easy to say that the geology and seismo-tectonics of a given site are different from those at Koyna, for example, but until we understand what it is in the physical environment of Koyna that led to the triggering of earthquakes there, this is not a very meaningful statement. And one must recognize that the various sites where major induced events have occurred represent a wide variety of geologic environments; there is as yet no recognized geologic theme at these localities which marks them as particularly distinctive or dangerous as compared to the thousands of apparently similar sites where large events have not occurred. Even nearby reservoirs that seem to be in the same geologic environment have sometimes given rise to widely disparate degrees of activity, as has recently been demonstrated at Manic 3 Reservoir, Quebec (Leblanc and Anglin, 1978).

 

Looks like this problem has been known for a while all over the world.

[Guest Tony n Terrific]

This is theory not scientific fact. There have been many man made disaters concerning Mother Nature. The Johnstown Flood in 1889 come mind. Anytime man tries to harness the power of nature he could be tempting fate.

Edited February 7, 2009 by Tony n Terrific (see edit history)

[Richard & Li]

http://www.johnmartin.com/earthquakes/eqpapers/00000054.htm

Reservoir-induced seismicity is considered to have occurred at four California sites. The four reservoirs and the largest triggered earthquake associated with each one are: Lake Mendocino in Mendocino County, M 5.2 (see CALIFORNIA GEOLOGY, December 1978, p. 275-281); Lake Crowley in Mono County, M 6.0 (see CDMG Special Report 150, p. 92-94); Lake Oroville in Butte County, M 5.7 (see CALIFORNIA GEOLOGY, June 1982, p. 115-118); and Lake Shasta in Shasta County, M <3.

 

 

CDMG is currently investigating seismicity at Lake Oroville. The seismicity at this location apparently is influenced or controlled by the seasonal variations in reservoir water storage, as indicated in the June 1982 issue of CALIFORNIA GEOLOGY . . . editor.

 

 

In numerous parts of the world today, including some of the most highly developed countries, many dam designers and operators have tended to close their eyes to the engineering problems posed by reservoir-induced earthquakes. One sometimes hears these kinds of defensive arguments: (1) no convincing correlation has yet been demonstrated between earthquakes and reservoirs; (2) since the natural seismicity at a given site is low, the danger of reservoir-inducement is therefore also low; (3) the geology at a given site is different from that at localities where major reservoir-induced events have occurred; (4) only three or four out of some 11,000 large dams worldwide have experienced significant induced earthquakes, and one should therefore not worry about a given site; and (5) no dam has yet failed disastrously because of a reservoir-induced earthquake, and the danger is thus grossly exaggerated. While many of these arguments have some elements of truth to them, they are essentially evading the primary issues: Virtually every careful study has concluded that there is indeed a cause-and-effect relationship between some earthquakes and some reservoirs, and two dams (Koyna, India, and Hsinfengkiang, China) have in fact come uncomfortably close to disastrous failure during such events. Furthermore, it is precisely in the regions of low natural seismicity where the major existing problems lie, because in areas of high seismicity dams are usually designed for substantial earthquake resistance anyway.

 

 

The unhappy current state of affairs is that our degree of understanding of reservoir-induced earthquakes is so minimal that almost no new reservoir anywhere in the world can be declared free of this possible danger. In particular, we do not know why such earthquakes occur, and we cannot as yet recognize with confidence those areas where reservoir-induced earthquakes are more likely than at other localities. It is easy to say that the geology and seismo-tectonics of a given site are different from those at Koyna, for example, but until we understand what it is in the physical environment of Koyna that led to the triggering of earthquakes there, this is not a very meaningful statement. And one must recognize that the various sites where major induced events have occurred represent a wide variety of geologic environments; there is as yet no recognized geologic theme at these localities which marks them as particularly distinctive or dangerous as compared to the thousands of apparently similar sites where large events have not occurred. Even nearby reservoirs that seem to be in the same geologic environment have sometimes given rise to widely disparate degrees of activity, as has recently been demonstrated at Manic 3 Reservoir, Quebec (Leblanc and Anglin, 1978).

 

Looks like this problem has been known for a while all over the world.

 

That's the way the article would have looked if it was unbiased and not an attempt to blame China for the disaster.

[Jeikun]

That's the way the article would have looked if it was unbiased and not an attempt to blame China for the disaster.

 

 

I don't think the article was a blame piece, it was just written in the easy-to digest without thinking to much, and shocking attention-grabbing way that pretty much all news stories made for general public consumption here in the USA are. Even an article about a cat stuck in a tree, a sinkhole, a kidnapping... same style. And since it's sensationalist to a degree, if you don't agree with it, it tends to piss you off. If you do agree with it, it tends to make you more sure of your opinion than perhaps you should be. And those are BOTH outcomes that they want. Either way you pay attention to it, have a reaction to it, and remember it.

[Richard & Li]

That's the way the article would have looked if it was unbiased and not an attempt to blame China for the disaster.

 

 

I don't think the article was a blame piece, it was just written in the easy-to digest without thinking to much, and shocking attention-grabbing way that pretty much all news stories made for general public consumption here in the USA are. Even an article about a cat stuck in a tree, a sinkhole, a kidnapping... same style. And since it's sensationalist to a degree, if you don't agree with it, it tends to piss you off. If you do agree with it, it tends to make you more sure of your opinion than perhaps you should be. And those are BOTH outcomes that they want. Either way you pay attention to it, have a reaction to it, and remember it.

 

I think you've hit the nail on the head.

 

I get so tired of that kind of tripe being passed off as 'news'... B)