Despite deaths, here's why scientists still call cave diving 'critical'
The death of two experienced cave divers highlights the perils faced by explorers. However, it's also a uniquely valuable way for scientists to study underwater systems.
In this June 2013 photo provided by National Geographic, diver Susan Bird, working at the bottom of Hoyo Negro, a large dome-shaped underwater cave in Mexico's Yucatan Peninsula, brushes a human skull found at the site while her team members take detailed photographs.
Paul Nicklen/National Geographic via AP
Two cave divers died over the weekend while exploring the Florida underwater system known as Eagle鈥檚 Nest, located about an hour north of Tampa, stunning their families and prompting calls for the closure of a notoriously perilous system.听
Chris Rittenmeyer, a Dallas-born digital technology specialist for the Boston Consulting Group, and his friend Patrick Peacock, an adjunct professor of history and philosophy at the Art Institute of Fort Lauderdale and operator of a non-profit dive group, were found at about 260 feet down, in a particularly labyrinthine section of the system, Exactly what went wrong during the dive is unclear, but family described them as experienced divers.
鈥淚聽guarantee you there was nothing left for them to do in the end,鈥� said Ron Rittenmeyer, the father of Chris, .听
鈥淢y son typically dove what he thought was his limit. I believe in his heart he did this dive fully expecting that he would be back,鈥� he said.
The tragedy seems to highlight how dangerous cave systems can be for even the most experienced of divers, and perhaps in particular for explorers seeking to test the limits of where they can go. Ten people have died at Eagle鈥檚 Nest since 1981, and the site was closed off for four years before divers successfully got it reopened in 2003, according to CBS.
鈥淚t鈥檚 the cave explorers that can get into more trouble because they鈥檙e doing more dangerous dives,鈥� Jim Garey, a professor at the University of South Florida who studies the biodiversity, hydrology and geochemistry of cave and aquifer systems, tells 海角大神. 鈥淚t鈥檚 far more dangerous than what I do. My goal isn鈥檛 to go as far or deep into the cave as I can, it鈥檚 to study what鈥檚 going on in the cave.鈥�
Divers first began plumbing underwater cave systems in the mid-1960s, with the advent of scuba apparatuses. And despite the high costs and the risk involved, for scientists, diving is an irreplaceable way to know more about the systems and tap secrets of broader import, as when from cave rock formations.
When drilling to collect samples, Dr. Garey tells the Monitor, researchers don鈥檛 know if they鈥檙e collecting water from a single source or several different ones, since a single aquifer can have different layers of water. 鈥淲hen you鈥檙e thinking about a spring from the surface, you鈥檙e looking at things flowing out of it, but it鈥檚 a complicated story underground.鈥�
As the Monitor noted in a 1982 article on cave divers in Florida, much of the area north of Tampa and west of the state鈥檚 central ridge is streaked with tunnels formed in limestone deposits.
Layers of limestone, which is largely compressed coral, were created each time the sea level rose to wash over the land. Those layers make up Florida's aquifer, the freshwater-laden rock that supplies most of the state's drinking water.
As the sea level receded, the limestone was exposed to rainwater, which is slightly acidic from carbon dioxide and soil acids. The acidity dissolved the limestone along its cracks and fissures, which created sinkholes dropping scores of feet, tunnels hundreds of feet long, and caverns as large as a football stadium.
The caverns became interconnected by the tunnels to form underground rivers that eventually pop out as springs. Some of those springs are along the marshland that borders the Gulf of Mexico, and the fresh water pouring out of them has become an integral part of the coastline ecology.
Tom Iliffe, a marine biologist and cave diving authority at Texas A&M University at Galveston, studies animals that inhabit salt water caves near the coast. Diving, he tells the Monitor, is 鈥渁bsolutely critical鈥� to his work.
鈥淭hey have a layer of fresh or brackish water on the surface,鈥� with the heavier salt water lying beneath. 鈥淭he animals I鈥檓 looking for occur only in this deep salt water layer in caves, and only by diving can we access this environment.鈥�
鈥淭here鈥檚 untapped potential here鈥� for scientists, he says. And he doesn鈥檛 pass over the charms of the experience. 鈥淔or the appropriate person, it can be absolutely fascinating and bewitching.鈥�