Drilling into debris-rich basal ice at the bottom of the NEEM (Greenland) borehole

Popp, Trevor J.; Hansen, Steffen B.; Sheldon, Simon G.; Schwander, Jakob; Johnson, Jay A. (2014). Drilling into debris-rich basal ice at the bottom of the NEEM (Greenland) borehole. Annals of glaciology, 55(68), pp. 199-206. International Glaciological Society 10.3189/2014AoG68A029

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After the NEEM (Greenland) deep ice-core drilling was declared terminated with respect to developing stratigraphic climate reconstructions, efforts were turned toward collecting basal ice-sheet debris and, if possible, drilling into the bedrock itself. In 2010, several meters of banded debris-rich ice were obtained under normal ice-drilling operations with the NEEM version of the Hans Tausen (HT) drill, but further penetration was obstructed by a rock in the path of the drill head at 2537.36 m. During short campaigns in 2011 and 2012, attempts were made to penetrate further using various reinforced ice cutters mounted on the HT drill head, tailored to cut through rock. These had some success in penetrating coarse material, but produced severely damaged cutters. Additionally a 51 mm diameter diamond cutting tipped rock drill was adapted to fit the NEEM drill. With this device, several additional meters of core containing subglacial sediments, rocks and rock fragments were collected. With these tools 1.39 m of additional material were obtained during the 2011 field season, and 7.1 m during 2012. Subglacial water refreezing into the newly formed borehole hindered further penetration, and the bedrock interface was not reached before final closure of the NEEM Camp.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Climate and Environmental Physics
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)

UniBE Contributor:

Schwander, Jakob

Subjects:

500 Science > 530 Physics

ISSN:

0260-3055

Publisher:

International Glaciological Society

Language:

English

Submitter:

Monika Wälti-Stampfli

Date Deposited:

22 May 2015 15:32

Last Modified:

22 May 2015 15:32

Publisher DOI:

10.3189/2014AoG68A029

URI:

https://boris.unibe.ch/id/eprint/68997

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