Polar research: School of rock
As Antarctica’s ice teams continue to hunt for the oldest ice their drills will reach, a smaller band of rockhounds is on a similar quest to plug the gaps in the geological record. The team now has a core that promises fresh insight into how Antarctica’s ice waxed and waned over the past few million...
| Main Author: | |
|---|---|
| Format: | Text |
| Language: | unknown |
| Published: |
DigitalCommons@University of Nebraska - Lincoln
2007
|
| Subjects: | |
| Online Access: | https://digitalcommons.unl.edu/andrillrespub/51 https://digitalcommons.unl.edu/context/andrillrespub/article/1051/viewcontent/Witze_NATURE_2007_School_of_rock__DC_VERSION.pdf |
| Summary: | As Antarctica’s ice teams continue to hunt for the oldest ice their drills will reach, a smaller band of rockhounds is on a similar quest to plug the gaps in the geological record. The team now has a core that promises fresh insight into how Antarctica’s ice waxed and waned over the past few million years. On December 26, 2006, a US$30-million international project called ANDRILL pulled up the final piece of a core from beneath the Ross ice shelf. Previous coring efforts have offered peeks into Antarctica’s deep history — back as far as 34 million years when the continent was first covered in ice. But the new core fills a gap in the ice shelf’s history, and sets a new Antarctic record for drilling depth. The period covered by the core — from the present to more than 5 million years ago — seems to be quite active. Preliminary analysis has revealed thick layers of a greenish rock interspersed throughout the core. This is an indication of open-water conditions, suggesting that the Ross shelf retreated and then advanced at least 50 times within the past 5 million years. With this nearly unbroken record, scientists can explore the history of the shelf in unprecedented detail. |
|---|