SAN DIEGO -- It's summer in Antarctica, and scientists from all around the world are flying to research stations on the frozen continent as part of a now years-long campaign to uncover the world's oldest ice.
At stake is the ability to more accurately predict planetary warming from greenhouse gas emissions.
One of the foremost experts on the hunt is Jeff Severinghaus, a paleoclimatologist at the University of California, San Diego's Scripps Institution of Oceanography. He believes that, after several years of tests, he could now be just months away from a major breakthrough using an experimental drill of his own design.
"The more we learn, the harder it's apparently going to be to find the ideal, unbroken ice-core, but we're not giving up," Severinghaus said in a recent interview with the San Diego Union-Tribune a few days before leaving for Antarctica. He added: "We're getting close to overcoming all the problems."
The international search will likely culminate in an epic expedition costing tens of millions of dollars and spanning the better part of a decade -- with researchers and technicians perched on a glacier 10,000 feet above sea level in subzero temperatures, drilling down more than two miles into the ice to carefully extract long cylindrical samples.
While such costly and time-consuming projects have been undertaken in the past, scientists have yet to find an ice sheet that continuously extends back more than a million years.
Researchers are now trying to pinpoint exactly where the next drilling project is most likely to unearth the most ancient ice-core samples.
To that end, Severinghaus is hoping up to conduct reconnaissance expeditions using a RAID or rapid access ice drill, which he has spent years building and testing. He first secured a $10.5 million National Science Foundation grant to kick-start the project about a decade ago.
The 100,000-pound tool doesn't extract ice-cores for research but rather creates a narrow, deep hole that allows researchers to evaluate the age of ice buried far within a glacier.
Estimating the age of ice at the lowest depths of a glacier has proved extremely challenging for researchers. Previous ice-core drilling has relied on radar, ice-flow models and other geophysical observations to estimate the location of scientifically useful ice sheets.