Speedy Antarctic drills start hunt for Earth’s oldest ice
▻http://www.nature.com/news/speedy-antarctic-drills-start-hunt-for-earth-s-oldest-ice-1.21061
In December, the first drill designed to search for a scientifically useful sample of ice that is at least 1.5 million years old will begin its work. It is part of a broader effort to locate the best place to extract a core containing Earth’s oldest ice, which would help to reveal how climate has shaped the planet’s past and how to predict future fluctuations.
[...] More than a decade ago, the European Project for Ice Coring in Antarctica (EPICA) drilled the oldest existing core, which contains 800,000-year-old ice, from an ice dome in East Antarctica known as Dome C. The core reaches only as far back as the latter part of the Pleistocene epoch, when Earth began cycling between warm and cold periods every 100,000 years. Before 1 million years ago, the cycle occurred every 40,000 years (...), so scientists want an ice core that is twice as old as EPICA to better understand this transition.
Digging such a core would cost about US$50 million and take several years, so researchers want to be sure that the location is optimal — with ice that is sufficiently deep but not melted at the bottom by geothermal activity. “It’s absolutely crucial to thoroughly investigate all options,” says Eisen. Enter a new breed of drill, designed to do fast, cheap reconnaissance instead of extracting a single, intact ice core, as previous deep drills have done.