Arizona Tries Tourism to Save "Living Cave"
National Geographic News
|April 19, 2005|
In 1974 cool, moist air billowed from a crack in Arizona's sunbaked
desert and lured cave hunters Randy Tufts and Gary Tenen underground.
There, glistening formations of rock hung from the ceiling like icicles
and sprouted from the ground. The explorers were overwhelmed. They'd
discovered a so-called living cave.
Tufts and Tenen were the first humans known to set foot in the Kartchner Caverns, which today are among the world's top show caves.
Kenneth Travous is the executive director of Arizona State Parks in Phoenix. He said the discovery of the caverns burdened Tufts and Tenen with an obligation to protect the underground labyrinth from ruin.
When Arizona State Parks staff people first saw the caves, "the same thing happened to us that happened to them," Travous said. "You look at it and you get overwhelmed with the responsibility of it."
The caverns are "living," a term used to describe active caves. "The cave formations still have water on them, they're still continuing to grow," said Rick Toomey, a staff scientist at the Kartchner Caverns in Benson.
Rainwater from the surface seeps through the ground, absorbing calcium carbonate along the way. Inside the cave, the mixture drips from the ceiling. As it hardens, it forms the icicle-like stalactites on the ceiling and sproutlike stalagmites on the floor.
With the exception of small cracks, the caverns are closed off to the outside world. The isolation allows the caverns to maintain an average temperature of 68 degrees Fahrenheit (20 degrees Celsius) and near 99 percent humidity.
Tufts and Tenen were concerned the arid desert air would dry out the caverns if the cracks were widened and people clambered through the murky, still depths. They kept their discovery secret for four years.
In 1978 the cavers shared the secret with the Kartchner family, the caverns' rightful landowners. Subsequently, the Arizona State Parks department staff, including Travous, was alerted to the existence of the caverns.
"What it came down to was [that] the best way to protect it was to develop it as a show cave. That's not something you would typically think would come to mind," Travous said. "But they did."
The parks department announced the discovery to the world in 1988. In 1999, 25 years after Tufts and Tenen first felt that cool, moist breeze, the public was invited to marvel at the glistening formations.
The state of Arizona spent 28 million dollars to acquire and develop the caves for tourism. The state had the advantage of avoiding the mistakes made with the development of other show caves that had been discovered many decades earlier.
With the Kartchner Caverns there was an opportunity to try to preserve them as living caves. Airtight doors, misters, a controlled lighting system, and a 3- to 4-foot-wide (90- to 120-centimeter-wide) path with 18-inch (46-centimeter) curbs are some of the measures designed to protect the caverns from tourist traffic.
"Also, every person that comes in is a little radiator giving off heat, giving off carbon dioxide and sometimes giving off extra water vapor," Toomey, the staff scientist, said.
To keep the human impact as low as possible, tour groups are limited to 20 people in the cavern known as the Rotunda Room, and 15 in the Big Room. The Big Room, Toomey added, is closed from April through September to allow a bat population to give birth and raise their young.
The bats, which begin to arrive in April, also support the caverns' living ecology. Bat guano is the sole energy source for critters such as mites, springtail insects, and cave spiders. During the winter, when the bats are absent, the insects are dormant and not bothered by tourists, Toomey said.
Toomey and his colleagues constantly monitor the caverns and surrounding area to gauge the human impact.
"We do see changes," Toomey said. "We see an increase in temperature and decrease in humidity. But we've run into some significant problems in fully understanding those."
Travous, the executive director of Arizona State Parks, explained that data on the caverns' temperature and humidity prior to their opening to the public was collected at the end of the regions' 15 wettest years in recorded history. The caverns' opening coincided with the onset of drought.
"We literally went from one end of the scale to the other," he said. "Since then, we've been trying to sort out which impacts have been ours and which is the natural scheme of things."
Toomey added that historical evidence suggests the caverns have dried more profoundly than what is happening currently. To definitively sort the human impact from the regional climate effects, the scientist is waiting for a return to wetter conditions.
Meanwhile, more than 200,000 people a year visit the Kartchner Caverns. Travous said "the whole thing was designed not to entertain so much but to instill in people the sense as they leave the park [that] it is their cave and the future depends on them."
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