Voyage to the Deep
Researchers go to great depths to learn more about our world
Cave explorer Hazel Barton lowers herself into a dark, damp hole. The pit is so large she can't see the walls around her. After a 50-meter (164-foot) drop, Barton's feet finally touch the ground. Barton has descended into one of the deepest caves in the United States: Lechuguilla (leh-choo-GHEE-yah) in Carlsbad, New Mexico.
Barton's headlamp shines on the cave's glittering features. Thin, pointy rocks hang like icicles from the ceiling rise up from the cave floor, others like rocky fingers reaching toward the surface. Barton looks around and realizes that parts of the cave walls look like they're covered in popcorn-shaped rocks.
Barton knows how lucky she is to see this underworld treasure. “These cave formations take millions of years to form ,” she says. “If one breaks, no one will ever see it again because it won’t grow back in our lifetime .”
In addition to dazzling sights, caves are also full of unusual kinds of life. Scientists find species in caves that aren’t found anywhere else on the planet. For these reasons, researchers risk their lives to study Earth’s underground worlds .
GOING UNDERGROUND
Explorers have discovered caves in places all around the world: in ice, rock, lava, and sand. The most common kind of cave is made when water washes through cracks between rocks. Over time, erosion enlarges these cracks through the rock, forming a cave.
“Caves also form underwater when coral reefs grow together and create small passageways and caverns,” says underwater cave explorer Kenny Broad.
Many caves give clues to what conditions were like long ago. “Let’s say you cut certain types of cave rocks in half and analyze them. You can learn what the climate was like hundreds of thousands of years ago,” says Broad. “Understanding how the climate has changed helps us understand what may be happening in the future,” he adds.
Scientists are also interested in mapping caves. City planners need to know the location of unstable underground caverns. That way,they can make sure no one builds structures over them.
WINDOW TO THE PAST
All sorts of species—from bacteria to bats—live in cave
ecosystems . Scientists want to know how these species
survive in places where the sun’s light can’t reach.
What do they eat? What role do they play on Earth as a
whole?
“Caves allow us to look at these interactions,” Barton
says. “There’s no light energy;” which
means organisms have to find another way to survive.
At the beginning of Earth’s history, organisms were not
able to turn the sun’s energy into food. That ability,
called photosynthesis , did not develop until about 2.6
billion years ago. So caves are like a window into Earth’s
past. They can show scientists what early lifeforms
might have looked like.
RISKY SCIENCE
Most caves are too complex to navigate with cameras or submarines. That’s why they’re among the last places that humans must physically visit to explore. And though exploring them is exciting, it’s also risky. When Broad dives into a water-filled cave, he must bring his own supply of air to breathe. If Broad doesn’t get back to the surface before his air runs out, he will drown.
Broad carries a backup air tank in case of an emergency. He also runs a guideline from the cave entrance. He can follow it out if he loses his way. Broad admits that the work can be nerve-racking. “You never know when something can fail you,” he says. “That’s why we bring lots of backup equipment.” Plus, caves can be dangerous environments, where falling rocks and landslides can occur with no warning. “I had a rock fall on my arm in New Zealand,” says Barton. “I ended up in the hospital for three days.”
Ultimately, explorers like Broad and Barton find that the rewards of cave research outweigh the risks. “Caves carry a lot of mysteries for us to try to understand,” Broad says.
