A promising target in the quest for a 1-million-year-old Antarctic ice core
May 23, 2018 by Hannah Hickey, University of Washington
The Allan Hills has older, blue ice exposed at the surface. Researchers towed their instrument on this wooden sled. The sloping topography and slippery surface made it challenging for radar surveys. Credit: Laura Kehrl/University of Washington
Ice cores offer a window into the history of Earth's climate. Layers of ice reveal past temperatures, and gases trapped in bubbles reveal past atmospheric composition. The oldest continuous ice core so far comes from Dome C in East Antarctica and extends back 800,000 years.
But a tantalizing clue recently offered the possibility to go back even further. A collaborative study between the University of Washington and the University of Maine now pinpoints a location where an entire million years of undisturbed ice might be preserved intact.
"There's a strong desire to push back the date of the oldest ice core record, to better understand what drives natural climate changes," said Laura Kehrl, a UW doctoral student in Earth and space sciences and corresponding author of the recent paper in Geophysical Research Letters. "The Allan Hills has been an area of interest since the 1970s, when scientists started finding lunar and Martian meteorites that had struck Earth long ago. Now we're discovering its potential for old ice."
The team gathered observations in Antarctica's Allan Hills Blue Ice Area, named for the blue ice that is exposed at the surface when ice above gets vaporized. This windy, desert area gets less than 1 centimeter of snow accumulation per year.
Read more at: https://phys.org/news/2018-05-quest-million-year-old-antarctic-ice-core.html#jCp