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Ice Mystery

Photo from University of Delaware

Researchers at the University of Delaware prepare to study an ice core sample from Vostok, a subglacial fresh-water lake in Antarctica.

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By KURT LOFT | The Tampa Tribune

Published: December 9, 2007

TAMPA - In the 1951 sci-fi classic "The Thing," researchers uncover a flying saucer buried in the Arctic tundra. They pull a frozen corpse from the wreckage and take it back to the base, where it thaws, wakes and goes on a rampage.

The movie was a metaphor about the atomic age and how, in the search for truth, science can unlock the unexpected. The theme is by no means irrelevant today. In bringing back samples from Mars, for example, do we risk unleashing an extraterrestrial virus? And if scientists pull ice cores from deep inside glaciers, could they unknowingly uncork a long-dormant plague?

The point isn't lost on researchers studying ancient microbes under the surface of the Antarctic ice shelf. A team from the University of Delaware and the University of California at Riverside recently captured ice samples at least 1 million years old that contain "time capsules" of microbial life.

"It's some of the coolest stuff I have ever worked on," said Craig Cary, a marine biologist at the University of Delaware. "We are going to gain access to the genetics of organisms isolated for possibly as long as 15 million years."

The ice core samples come from one of the most mysterious places on Earth — Lake Vostok — which lies hidden more than two miles beneath the frozen surface of Antarctica. Vostok is the largest of about 140 subglacial fresh-water lakes in Antarctica. It was discovered in 1996 by scientists using radar, and many experts call it the most untainted lake on the planet.

Back in their labs, the scientists are examining water thawed from the core samples for exotic microorganisms that have survived the ages in total darkness and freezing cold and without food and energy from the sun. Sponsored by the National Science Foundation, the research is part of the International Polar Year, a project looking at how life adapts to extreme environments.

The core segments, from nearly 12,000 feet underground, were melted under meticulous conditions to prevent accidental contamination, and scientists also took great care in drilling the hole.

"Since the lake has not had direct contact with the surface world for at least 15 million years," Cary said, "this would be a contamination of one of the most pristine environments on Earth."

A sample of the core, shown in a photo on this page, was treated with kit gloves. Researchers placed it in an isolation chamber to melt, ran it through a special filtering system and used a bleaching solution to destroy any contaminating bacteria or DNA from the outside the core. Scientists wore sterile jumpsuits at all times.

Team members also took precautions to protect themselves and the lab from any possible contamination from the ancient sample. The core has been stored at 35 degrees below zero at the National Ice Core Laboratory in Denver.

"It was very exciting to see the Vostok ice, knowing how old it is and how much it took to get that ice to the lab," said Julie Smith, a doctoral student in marine and earth sciences at Delaware. "The ice core itself was incredibly clear and glasslike, reflecting the light like a prism."

Scientists have identified the micro-organisms living in the Vostok water, but they don't know what they do or how they adapted to such a cold, dark, isolated environment.

"This research is important because it will give us insight into how microbes can survive in a very energy-limited system," Smith said. "Most of our planet is permanently cold and dark, so it makes sense that we should study how life exists under these conditions."

Reporter Kurt Loft can be reached at (813) 259-7570 or kloft@tampatrib.com.

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