Drilling the new 5G-5 branch hole at Vostok Station for collecting a replicate core of old meteoric ice
2021; Cambridge University Press; Volume: 62; Issue: 85-86 Linguagem: Inglês
10.1017/aog.2021.4
ISSN1727-5644
AutoresA. V. Turkeev, N. I. Vasilev, V. Lipenkov, A. V. Bolshunov, Alexey Ekaykin, Andrei Nikolaevich Dmitriev, D. A. Vasilev,
Tópico(s)Climate change and permafrost
ResumoAbstract Recent studies have shown that stratigraphically disturbed meteoric ice bedded at Vostok Station between 3318 and 3539 m dates back to 1.2 Ma BP and possibly beyond. As part of the VOICE (Vostok Oldest Ice Challenge) initiative, a new deviation from parent hole 5G-1 was made at depths of 3270–3291 m in the 2018/19 austral season with the aim of obtaining a replicate core of the old ice. Sidetracking was initiated using the standard KEMS-132 electromechanical drill routinely employed for deep ice coring at Vostok, without significant changes to its initial design. Here we describe the method and operating procedures for replicate coring at a targeted depth in an existing slant hole, involving the use of a cable-suspended electromechanical drill. The design of the milling cutter head used for sidetracking is presented. The performance characteristics and the experience of drilling branch-hole 5G-5 at Vostok are described and discussed.
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