Theoretical and Experimental Analysis for Cleaning Ice Cores from Estisol TM 140 Drill Liquid

To reconstruct climate history of the past 1.5 Million years, the project: Beyond EPICA Oldest Ice (BEOI) will drill about 2700 m of ice core in East Antarctica (2021–2025). As drilling fluid, an aliphatic ester fluid, Estisol TM 140, will be used. Newly drilled ice cores will be retrieved from the...

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Bibliographic Details
Published in:Applied Sciences
Main Authors: Francesco Enrichi, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Carlo Barbante
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2021
Subjects:
T
Online Access:https://doi.org/10.3390/app11093830
https://doaj.org/article/bee4f35d1d6a44ecad1049d538f4b042
Description
Summary:To reconstruct climate history of the past 1.5 Million years, the project: Beyond EPICA Oldest Ice (BEOI) will drill about 2700 m of ice core in East Antarctica (2021–2025). As drilling fluid, an aliphatic ester fluid, Estisol TM 140, will be used. Newly drilled ice cores will be retrieved from the drill soaked in fluid, and this fluid should be removed from the cores. Most of it will be vacuum-cleaned off in a Fluid Extraction Device and wiped off with paper towels. Based on our experiences in Greenland deep ice coring, most of the residual fluid can be removed by storing the cores openly on shelves in a ventilated room. After a week of “drying”, the cores have a dry feel, handling them do not give “wet” gloves and they can easily be marked with lead pencils. This paper presents a theoretical investigation and some simple testing on the “drying” process. The rates of sublimation of ice and evaporation of fluid have been calculated at different temperatures. The calculations show that sublimation of the ice core should not occur, and that evaporation of fluid should be almost negligible. Our test results support these calculations, but also revealed significant fluid run-off and dripping, resulting in the removal of most of the fluid in a couple of days, independent of temperature and ventilation conditions. Finally, we discuss crucial factors that ensure optimal long-term ice core preservation in storage, such as temperature stability, defrosting cycles of freezers and open core storage versus storage of cores in insulated crates.