Post by L Roebuck on Jun 15, 2006 10:13:39 GMT -5
Arizona caverns raise the standards for study, thrill of subterranean life
David Brown, Washington Post
Walking around inside Kartchner Caverns, it is easy to understand why the people who discovered limestone caverns in centuries past couldn't resist turning them into the equivalent of theme parks.
It's a spooky, gorgeous, damp and quiet world. The mineral accretions protruding from ceilings, floors and walls evoke images from the mythic to the gastronomic -- Kubla Khan to fried eggs. They make a visitor want to touch, explore, participate, experiment.
In Kentucky's Mammoth Cave, ("discovered" in the 1790s, but known long before to aboriginal people), tour guides used to put on torch-throwing demonstrations to dramatically illuminate interior spaces. Couples used to get married in Virginia's Luray Caverns. One room there is rigged with a system of mechanically controlled hammers that play tunes on the stalactites, like an organ.
None of that will happen here.
In Kartchner Caverns, if someone touches a stalactite, it is instantly "remediated" -- wiped down with a 10 percent bleach solution. The lighting, while dramatic, is designed to add as little heat as possible. Visitors are misted with water before entering so they will shed less hair and skin on the tour. Those sources of carbon, nitrogen and microbial life were unknown to the cave ecosystem for eons, and they are not wanted now.
In size, Kartchner is tiny, with 2.5 miles of passageway, compared with 365 miles in Mammoth, the world's largest known cavern. But it is setting a new standard for how to achieve three often conflicting goals: preserving the cave, exploiting it for scientific research and running a tourist attraction.
The newest large cave to be opened to the public, Kartchner was discovered in 1974 by two amateur cave explorers, Gary Tenen and Randy Tufts. They didn't tell the landowners about it until 1978. The public wasn't informed of its existence about 40 miles southeast of Tucson until 1988, when the state bought it. Part of it opened in 1999, a second section in 2003.
"Finding that cave was like having a child," Tenen and Tufts once wrote. "We felt responsible for it ... we made a sort of promise to the cave, that it could trust human beings."
One of the original manifestations of that responsibility was an extensive assessment of Kartchner's virginal state -- everything that was at risk.
This included measuring environmental variables such as temperature, humidity and carbon dioxide concentration, and assessing past and present contacts with the outer world. The latter included studying prehistoric bones (including one from an 86,000-year-old ground sloth), dating bat guano deposits (up to 46,000 years old), and describing the comings and goings of about a thousand female bats, which use one of the rooms as a nursery each summer.
"The data set that is being produced at Kartchner is a data set that no one ever had before," said Robert R. Casavant, an associate professor of geoscience at the University of Arizona, who is helping direct research at Kartchner.
Other caves could have benefited from having been known earlier and more completely.
Mammoth Cave once was home to large numbers of Indiana bats, a threatened species. At some point they disappeared. Studies of the species showed they hibernated in environments between 37 degrees and 45 degrees Fahrenheit. The part of the cave they used to inhabit is now closer to 54 degrees, said Rickard S. Toomey, director of science at Mammoth, who until last year had the same position at Kartchner.
"Temperature and humidity are the vital signs of the cave, telling you whether it is well or ill. The bat population would be another one of the vital signs," he said.
New Mexico's Carlsbad Caverns installed an elevator in 1931. As early as the 1940s, guides noticed that some of its pools appeared to be shrinking. It turned out the elevator shaft acted like a huge chimney, venting off cave moisture. In the 1970s, air locks were installed to block the effect.
Kartchner opened to the public with four airlocks. From mid-April to mid-October each year, managers close the section of the cavern used by the bats. They know that since the cave was opened to the public, the temperature in its deepest part (called "Echo Passage") has risen 2 degrees, while the relative humidity has fallen from 99.3 to 98.8 percent.
But preservation doesn't come cheaply.
Special low-impact blasting techniques had to be used to create the walkways, which are wheelchair-accessible. No gas-powered equipment was used inside the cave, so as not to pollute the air. Some of the wiring had to be redone after it was discovered that lubricating creams in conduits supported fungal growth. Signs inside the cave were replaced when "nonnative" bacteria were found on them, living off the paint. In all, development of the cave cost about $10 million.
Kartchner is also producing new science, not just preserving its old state.
Perhaps the most notable research from the cavern was a pair of papers published last year that explained why stalactites are shaped the way they are. Although the chemistry of their formation was long known, the physical and mathematical calculations explaining their carrotlike shape -- astonishingly -- had never been done. Raymond E. Goldstein, a professor of physics as the University of Arizona at Tucson, and his students took it on.
They made calculations predicting how the shape should evolve based on the rate that calcite precipitates out of the drip water in the cave, the thickness of water films on the budding stalactites and other variables.
They determined that there was an "attractor" in the process -- a single shape all stalactites in all caves tended toward. They drew this shape on computers using their equations, and then went to Kartchner and checked it against laser-guided measurements of stalactites there. It fit nearly perfectly.
"As with the Platonic solids of antiquity -- the circle, the square, etc. -- which are ideal forms independent of scale, this too is a Platonic ideal," they wrote.
Full Article: www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/06/04/BAG26J56EB1.DTL&feed=rss.bayarea
David Brown, Washington Post
Walking around inside Kartchner Caverns, it is easy to understand why the people who discovered limestone caverns in centuries past couldn't resist turning them into the equivalent of theme parks.
It's a spooky, gorgeous, damp and quiet world. The mineral accretions protruding from ceilings, floors and walls evoke images from the mythic to the gastronomic -- Kubla Khan to fried eggs. They make a visitor want to touch, explore, participate, experiment.
In Kentucky's Mammoth Cave, ("discovered" in the 1790s, but known long before to aboriginal people), tour guides used to put on torch-throwing demonstrations to dramatically illuminate interior spaces. Couples used to get married in Virginia's Luray Caverns. One room there is rigged with a system of mechanically controlled hammers that play tunes on the stalactites, like an organ.
None of that will happen here.
In Kartchner Caverns, if someone touches a stalactite, it is instantly "remediated" -- wiped down with a 10 percent bleach solution. The lighting, while dramatic, is designed to add as little heat as possible. Visitors are misted with water before entering so they will shed less hair and skin on the tour. Those sources of carbon, nitrogen and microbial life were unknown to the cave ecosystem for eons, and they are not wanted now.
In size, Kartchner is tiny, with 2.5 miles of passageway, compared with 365 miles in Mammoth, the world's largest known cavern. But it is setting a new standard for how to achieve three often conflicting goals: preserving the cave, exploiting it for scientific research and running a tourist attraction.
The newest large cave to be opened to the public, Kartchner was discovered in 1974 by two amateur cave explorers, Gary Tenen and Randy Tufts. They didn't tell the landowners about it until 1978. The public wasn't informed of its existence about 40 miles southeast of Tucson until 1988, when the state bought it. Part of it opened in 1999, a second section in 2003.
"Finding that cave was like having a child," Tenen and Tufts once wrote. "We felt responsible for it ... we made a sort of promise to the cave, that it could trust human beings."
One of the original manifestations of that responsibility was an extensive assessment of Kartchner's virginal state -- everything that was at risk.
This included measuring environmental variables such as temperature, humidity and carbon dioxide concentration, and assessing past and present contacts with the outer world. The latter included studying prehistoric bones (including one from an 86,000-year-old ground sloth), dating bat guano deposits (up to 46,000 years old), and describing the comings and goings of about a thousand female bats, which use one of the rooms as a nursery each summer.
"The data set that is being produced at Kartchner is a data set that no one ever had before," said Robert R. Casavant, an associate professor of geoscience at the University of Arizona, who is helping direct research at Kartchner.
Other caves could have benefited from having been known earlier and more completely.
Mammoth Cave once was home to large numbers of Indiana bats, a threatened species. At some point they disappeared. Studies of the species showed they hibernated in environments between 37 degrees and 45 degrees Fahrenheit. The part of the cave they used to inhabit is now closer to 54 degrees, said Rickard S. Toomey, director of science at Mammoth, who until last year had the same position at Kartchner.
"Temperature and humidity are the vital signs of the cave, telling you whether it is well or ill. The bat population would be another one of the vital signs," he said.
New Mexico's Carlsbad Caverns installed an elevator in 1931. As early as the 1940s, guides noticed that some of its pools appeared to be shrinking. It turned out the elevator shaft acted like a huge chimney, venting off cave moisture. In the 1970s, air locks were installed to block the effect.
Kartchner opened to the public with four airlocks. From mid-April to mid-October each year, managers close the section of the cavern used by the bats. They know that since the cave was opened to the public, the temperature in its deepest part (called "Echo Passage") has risen 2 degrees, while the relative humidity has fallen from 99.3 to 98.8 percent.
But preservation doesn't come cheaply.
Special low-impact blasting techniques had to be used to create the walkways, which are wheelchair-accessible. No gas-powered equipment was used inside the cave, so as not to pollute the air. Some of the wiring had to be redone after it was discovered that lubricating creams in conduits supported fungal growth. Signs inside the cave were replaced when "nonnative" bacteria were found on them, living off the paint. In all, development of the cave cost about $10 million.
Kartchner is also producing new science, not just preserving its old state.
Perhaps the most notable research from the cavern was a pair of papers published last year that explained why stalactites are shaped the way they are. Although the chemistry of their formation was long known, the physical and mathematical calculations explaining their carrotlike shape -- astonishingly -- had never been done. Raymond E. Goldstein, a professor of physics as the University of Arizona at Tucson, and his students took it on.
They made calculations predicting how the shape should evolve based on the rate that calcite precipitates out of the drip water in the cave, the thickness of water films on the budding stalactites and other variables.
They determined that there was an "attractor" in the process -- a single shape all stalactites in all caves tended toward. They drew this shape on computers using their equations, and then went to Kartchner and checked it against laser-guided measurements of stalactites there. It fit nearly perfectly.
"As with the Platonic solids of antiquity -- the circle, the square, etc. -- which are ideal forms independent of scale, this too is a Platonic ideal," they wrote.
Full Article: www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/06/04/BAG26J56EB1.DTL&feed=rss.bayarea