There is a chemical smell in the basement of Shepherd Labs at the University of Minnesota, and, not surprisingly, a big, humming lab with powerful-looking equipment and a radiation symbol on the door. There is no natural light whatsoever. Through some double doors is found an tiny office with (and this is just the surface layer) a scrap metal heap in one corner, crowned by a mounted metal vacuum tube and a carefully balanced, nonfunctioning black bike; some lead plates; a glacier of papers and magazines; a can of Mod Podge decoupage glue; several gutted laptops; two desktop computers with three plastic “Star Wars” toys on top of the monitors; several industrial-sized plastic chemical containers, and a box of slides of very thin rock samples from New Caledonia. New Caledonia is near Papua New Guinea. After some excavation, a box of very rare Polaroid film was discovered, and below that, a desk.
Which is to say, a visitor found geologist Nick Seaton in his natural, underground, sedimentary environment.
It was the perfect setting to learn something about caving, a hobby that, like Seaton’s subterranean office, combines curiosity with a whole lot of practical, scientific applications.
Seaton is officially Dr. Nicholas Seaton, a department safety officer in the Characterization Facility in the College of Science and Engineering. He is scruffy, attired in a T-shirt with cartoon Tyrannosaurus rexes at a recent meeting, and he’s exceedingly knowledgeable about caves. He’s also British. Seaton emigrated to Minnesota from Liverpool, England, in 2007 for the job he currently holds at the U, which, in part, involves discerning the preferred orientation of rock crystals.
He described his introduction to caving like this: “I’m a geologist by training, interested in rocks and fossils and things. When I was a college freshman in Liverpool they invited us all into a big hall to choose a hobby. One of the booths was the caving club. I thought, Why the hell not? Give it a go. You didn’t even have to pay to see if you liked it. You could go on a trip and learn how to use ropes and ladders. It was lots of fun. I joined the club, and also took up rock climbing.”
Soon after his move, Seaton, 36, joined the Minnesota Speleological Survey. It’s the local grotto, in caver speak, of the National Speleological Society. Seaton served as the club’s president until last August. The group has 40 to 50 active members.
“Nick brought a lot of experience with ascending and descending,” said MSS vice president Al Savage. “In England, they have more pits. He was able to train us in single rope technique. He’s definitely one of the most experienced cavers in Minnesota. If there was an emergency, he’s one I would call.”
While certainly knowledgeable and experienced, Seaton stokes his interest in caving through the things he doesn’t know. “I’ve been the first person ever in a cave — that’s fun. You don’t know what’s going to be down there. Caving is one of the few unknowns. It’s like mountain climbing, but inverse — you can see where you’re going on a mountain. You don’t know how far a cave goes. It’s fun to explore stuff that most people will never see, and it’s very pretty down there.”
Caving, it appears, has a lot more public service and scientific applications than most hobbies, including mapping and exploration, groundwater protection, cave rescues and biological studies. The interest also is a resource for government and private construction projects, reconnaissance of caves and sinkholes for private landowners, cave research on other planets, and archaeological excavations.
Below are edited excerpts of a conversation with Seaton:
In Minnesota, caves are often full of mud and sand. If you get permission from the landowner, you can dig to clear passages, and in the process, we’ve come across stone tools, arrowheads, animal bones. Some years ago at a cave in the Spring Valley (Wis.) area, we found the skull of a sabertooth tiger.
Minnesota on the cave spectrum
Almost all caves are formed in limestone. Some are sandstone or lava tubes, but most are limestone or gypsum, and most are in the southeast corner of Minnesota because that’s where most of the limestone is. We don’t have that many caves because we don’t have much limestone — probably 100 caves in Minnesota. And our caves tend to be two-dimensional and branching because the limestone is horizontal. The area where Tennessee, Alabama and Georgia come together, called TAG, is a hot spot. There are thousands of big caves there. And the limestone is tilted so there are big drops, hundreds of feet, that require rappelling. The biggest caves in the world are in Borneo and Sarawak (Malaysia). I’d love to go there.
An explosive discovery
Five or six years ago, there was a big rain event down in the Spring Valley area. A farmer came out to his field and found a lake. Next day, the lake was gone but there was a big hole and massive 50- or 60-pound chunks of rock scattered around on the ground. The cave underground, which had been there for tens of thousands of years, filled up with rain water and the pressure just blew out the rock closest to the surface. I would have liked to see that.
A reason not to cave in the winter
Many caves in Minnesota are closed during winter so as not to disturb the bats during hibernation. They have a limited supply of fat to burn, and it takes energy to fly around. If they wake up more than a couple times during the winter, they don’t have enough fat to last them. White nose syndrome, a virus that’s spread here from the East Coast, causes bats to die for a similar reason. Their immune systems kick in, they wake up in the middle of winter, and there are no mosquitoes to eat, so they starve. They found several hundred dead bats Up North at the Soudan cave because of white nose syndrome.
A reason to cave in the winter
There’s a little cave on the same property as Mystery Cave where the water in it comes to within eight inches of the roof. That’s tricky. If water on the surface is frozen, it can’t flood the cave, so we go to those in the winter.
A lot of caves in Minnesota are on private property, so you have to knock on the door, talk to the landowner for five or 10 minutes to convince them you know what you’re doing, and then off you go. The MSS doesn’t publish the location of caves because we don’t want inexperienced people to hurt themselves. Three people is minimum; that way you can send one person out for help while one person can help someone who’s injured. Five or six people is a good size.
A cave is not discovered all at once. It takes a lot of people going in and out to find all the bits. There are 13 miles of cave in the Spring Valley caverns that took years to discover and map. It’s very easy to walk by an opening to a new passage and not notice it behind a boulder. Caves breathe. There’s a saying — If it blows, it goes — meaning there’s probably more passage to explore if you feel air moving.
Things that make cave exploration harder are if the passage is narrow or steep; if there are big drops that require ladders and equipment; wet caves require a wet suit, and can be more difficult; and caves with big boulders all piled up — those take forever. If there’s a hole going down, you go feet first, so if you want to turn around you’re already oriented the right way.
How do you find your way out?
Walk down a passage. Every time there’s a junction, choose which way you’re going to go, then look back and make sure you know what it looks like coming back. You basically memorize it. Things look way different coming from the other direction, especially when you’re only seeing the small circle illuminated by your headlamp. Just moving your head differently can give you an entirely different view of the same location.
How do you map a cave? It’s old school. There are no apps because there’s no cell connection underground. You use waterproof graph paper and pencil. On one side, you write the readings, and on the other, you sketch what the passage looks like. It takes three people to map. You run a tape measure as straight as possible until the passage takes a turn, then take a compass bearing along that line. You take an inclination reading to see whether the tape is sloped up or down. At each reading, you measure from ceiling to floor, and to both sides. Surveying takes a long time. Once we measured 800 feet in 33 sections — legs, we call them. That took us five or six hours.
A little lost
Once in northern Spain, we were exploring a new cave. We had to bring dive gear down for other cavers, and the round trip took about 13 hours. We got a little lost at one point; we’d taken a wrong turn. Lost is the wrong term — we knew where we were. It just wasn’t where we wanted to be. We were in a big tube, 30 feet across, with several entrances and we walked straight past the entrance we’d come in.
Why no fuzzy gloves? Why are zippers destroyed? Why bring a foam butt pad for safety? Why no crumbs?
Lint from fleece gloves and clothing sticks to rough cave surfaces. We’ll have cleaning trips in show caves that are open to the public, like Mystery Cave, and pick up pounds and pounds of fuzzy lint. Caves are incredibly muddy, so zippers get clogged with mud. As to the foam pad, rocks are cold. If you have to sit on the cold ground, hypothermia can set in pretty quick. A little square of foam to sit on can save your life if you need to wait for help. And crumbs? Caves are low energy systems, very fragile. Crumbs, like from a muffin or sandwich, are high energy. Even a couple crumbs cause an explosion of fungus — it’s a mess.
How long do most caving trips last?
Most are five or six hours. The longer you’re in there, the more you have to carry — overnight gear, food, pee and poo considerations. You want to label your pee bottle very carefully.
Sarah Barker is a freelance writer from St. Paul.