An American research team finished drilling through a half-mile of Antarctic ice on Monday, reaching the surface of subglacial Lake Whillans and retrieving water samples that will be studied for the presence of life, according to the team’s Web site.

Of the hundreds of buried lakes that lie sealed under the Antarctic ice, only one, Lake Vostok, had previously been reached, by a Russian team a year ago. Samples of that lake have not yet been fully analyzed.

Lake Vostok, two miles deep, was reached with a different sort of drill that risked the danger of contaminating the buried lake with drilling fluid. The American team, supported by $10 million in grants from the National Science Foundation, used a custom-designed hot water drill with filtration and other technology to avoid contamination.

The researchers hope to explore the lake with a remotely operated submersible and take samples of sediment from the lake bottom. They are looking not only for microbial life, which could give clues to the kind of life that might exist elsewhere in the solar system, but for information about past climate, water flow and ice movement.