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Ice core sample taken from drill. An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier.Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ice formed over a range of years.
Ice cores are one of the most important motivations for drilling in ice. Since ice cores retain environmental information about the time the ice in them fell as snow, they are useful in reconstructing past climates, and ice core analysis includes studies of isotopic composition, mechanical properties, dissolved impurities and dust, trapped ...
This is a list of ice cores drilled for scientific purposes. Note that many of these locations are on moving ice sheets, and the latitude and longitude given is as of ...
A recently-discovered ice core taken from beneath Greenland’s ice sheet decades ago reveals that much of the country was ice-free around 400,000 years ago – an alarming finding that could have ...
The core, which Putkonen estimates is between 4 and 5 million years old, was discovered during a 2018 expedition in Antarctica. He said the 10 meter-long core contains invaluable information for ...
The isotopic ratio of 18 O to 16 O, usually in foram tests or ice cores. High values mean low temperatures. Confounded by ice volume - more ice means higher δ 18 O values. Ocean water is mostly H 2 16 O, with small amounts of HD 16 O and H 2 18 O. In Standard Mean Ocean Water (SMOW) the ratio of D to H is 155.8 × 10 −6 and 18 O/ 16 O is ...
An ice core which contains samples of Earth’s atmosphere from five million years ago has been pulled up from the continent’s Ong Valley, researchers have said.
Initially the glacial/interglacial cycle length was about 41,000 years, but following the Mid-Pleistocene Transition about 1 Ma, it slowed to about 100,000 years, as evidenced most clearly by ice cores for the past 800,000 years and marine sediment cores for the earlier period. Over the past 740,000 years there have been eight glacial cycles.