Document DetailsThe investigation and experience of using ESTISOLTM 240 and COASOLTM for ice-core drilling
|Authors:||Sheldon SG, Steffensen JP, Hansen SB, Popp TJ, Johnson SJ|
|Keywords:||glaciological instruments and methods, ice core, ice coring, ice engineering|
|Periodical/Journal:||Annals of Glaciology|
Continuous good-quality deep ice cores provide excellent scientific data with which to reconstruct a past climate record for >800ka. At depths starting from ~100m using an electro-mechanical drill, a drilling liquid is essential for successful recovery of the very high-quality ice cores demanded by modern scientific analysis techniques (e.g. continuous flow analysis). Finding a suitable drill fluid for use at deep ice-coring drill sites is not an easy task. Temperatures vary greatly not just from site to site, but also at a site where the average mean temperature from surface to bedrock can vary from -55°C to -2.75°C. In the past 60 years, many fluids have been used, with varying degrees of success, but for various reasons are either unavailable, are now considered unsafe and dangerous or are too environmentally damaging to be permitted. Here we report on our pre-season investigation into possible candidate drill fluids, with specific information concerning ESTISOLTM 240 and COASOLTM, the rationale behind the redesign of our drill successfully used at NorthGRIP, Greenland, and EPICA DML, Antarctica, the knock-on effect of those changes, and our field experience in Greenland at Flade Isblink in 2006 and at NEEM in 2009-10.