Mapping Mammoth: Cave diver explores unknown passages

Mammoth Cave
In this 2011 file photo, stone formations are seen in the Mammoth Dome area of Mammoth Cave during a tour in Mammoth Cave National Park, Ky.
Ed Reinke | AP

Cave diver Mark Wenner is expanding the known reaches of Mammoth Cave, 10 feet at a time.

Sometimes swimming in silt-out conditions, the 1972 Technical High School grad and a team of divers record distance, depth and direction, the St. Cloud Times reported. Knots in the rope mark 10-foot increments. Divers' data collection is far more precise.

"Unless you bring back the photos and the video and the measurements, actual hardcore data that gets logged into the computer, nobody knows where you were. And there's no proof that you went anywhere," Wenner said.

Wenner, a former high school swim team captain who got some of his experience in the Melrose Quarries and under the ice of Little Birch Lake, has been cave diving around the world. It's a pursuit he followed in California, where he was a drummer, and in Tennessee, where he built recording studios for musicians.

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He's seen a fire ring from the ice age, a perfect black circle contrasting with bleached-white surroundings, in the Yucatan Peninsula's White Cave river system. He's seen a pile of 10,000-year-old mastodon bones in the Mammoth system.

"Those types of things are everywhere. We just don't know that they're there. We've discovered everything. We've been in space. The science community knows the underground river system, the aquifer system is the totally unexplored part of this world," Wenner said.

At Mammoth Cave, Wenner and his team provide cartographer Pat Kambesis of the Cave Research Foundation with the data she needs. The endeavor could more than double the cave's 405 charted miles.

Kambesis said more than 5,000 miles of caves exist in the Flint Ridge-Mammoth Cave System. But not all of it is connected. Among her projects: Seeking a connection between the Mammoth and Whigpistle cave systems.

Since the late 1980s, she and others have added about 55 miles to the mapped part of Mammoth Cave. Mapping provides the base for other scientific exploration. Kambesis is interested in the hydrology of cave systems. One way her findings could be used is to monitor the effect irrigation has on the water table.

"We are after passage. We are after connecting things. Connecting Point A to Point B. If they don't know where B is, we have to go find it, and in the process of finding that passage we have to map everything down to the tenth of an inch," Wenner said.

On the first pass, the crew sets the line — that rope knotted every 10 feet — and collects raw data. Divers shoot photos and video. On their next pass, visibility is better. Because they're not setting a line, they're able to keep their feet off the floor. Their breathing is calmer, so they stir up less sediment. They're able to sketch a few things. They take notes on Mylar.

"There's no difference between being on the moon and being in a cave at the end of a cave system like Mammoth," Wenner said.

"When they shut that door on that space capsule, you're breathing oxygen in a bottle and you're breathing out of a rebreather. You're not going to get back to Earth unless that engine starts and a whole bunch of people support you to get back there. It's the same exact feeling. As soon as you leave, you've got your scooter in front of you and you've got your medical-grade oxygen bottles hanging from you and your mixed gasses and your computer and your rebreather. It's the same exact feeling. You're on a mission. We do the same exact thing. They're collecting data up there, they're collecting rock samples, spores. We're doing the same exact thing, it's just that we're doing it here."

Scientists rely on cave divers to bring back samples from places they can't go. Sometimes it's tiny shrimp. Sometimes it's water samples.

"They're cold and they're dark and they're scary looking and I don't know if I would have the nerve to dive," Kambesis said by phone from Western Kentucky University, where she teaches geography.

On the surface, the data is meshed with topographic overlays. What comes out of a cave can give researchers a better idea of how aquifers work, inform prospectors seeking oil and gas, potentially lead to new biological discoveries.

Divers don't always know how the samples will be used; they just follow instructions.

"Mark is really very, very enthusiastic, and he's also a real details guy. So he doesn't like to leave anything to chance, which of course is very good for cave diving. He's the guy that makes the lists. He's very, very organized and thorough in his preparation," Kambesis said.

He's seen what can happen when a sense of adventure overtakes safety.

"I'm getting old enough that I probably shouldn't be risking my life. My wife (Lyndie White-Wenner, singer/songwriter who had a hit with Kenny G and now works as a publicist) is very concerned about that. You get to the point when you're not even insurable anymore and you have to think about that. Is that how I'm going to meet my maker or do I want to help direct other people?"

Wenner was surprised when his short presentation at the National Speleological Society Cave Diving Section, titled "Procedures and Protocols," brought a flurry of requests for copies. He's looking to expand that endeavor.

"You don't learn any of this in school," Wenner said "You can learn how to scuba dive, but there is no one that can teach you to do what we're doing. It's a discipline that is impossible because there's too many components."

Friends of his have taken fatal risks — sometimes with equipment, sometimes by overrating their abilities (cave diving requires climbing and swimming skills), sometimes by failing to reveal a medical condition.

"His family and his friends do worry about that risky element," said Mark Sakry, a childhood friend, former Stearns County commissioner and current executive director of the Boys & Girls Club of Central Minnesota. "He has seen places in the world few people get to. Maybe a few people from National Geographic will get there, but Mark is right there in the thick of it in the diving world."

The wonder isn't lost on Wenner.

"Look at pictures of caves. You'll see stuff that doesn't even look real. It looks like another planet. And it's this planet," Wenner said.

He described a camping spot on pillowy soft sand — a departure from what often can be a muddy endeavor.

"When you are by yourself and you surface out of a river and nobody's there and nobody's ever been there — I can't tell you what that feels like. You're completely by yourself. And if you're not completely comfortable with yourself, you don't want to stay there very long. Complete peace. But most people, they don't carry complete peace."

This is an AP Member Exchange shared by Ann Wessel of the St. Cloud Times