HUNTING FOR ANTARCTICA'S OLDEST ICE

• Published in: Ice and Snow
• Main Authors: V. Lipenkov Ya., A. Ekaykin A., В. Липенков Я., А. Екайкин А.
• Other Authors: Russian Science Foundation (grant 1817-00110), Российский научный фонд (грант № 18-17-00110)
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2018
• Subjects: Antarctica; deep drilling; ice dating; Mid-Pleistocene Transition; oldest ice; paleoclimatic reconstruction; Антарктида; гидраты; глубокое бурение; датирование льда; древний лёд; климатическая перестройка; палеоклиматическая реконструкция; плейстоцен; Antarctic; The Antarctic; Austral; East Antarctic Ice Sheet; Vostok Station; Antarc*; Antarctic Science; EPICA; ice core; Ice Sheet; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/460; https://doi.org/10.15356/2076-6734-2018-2-255-260

One of the key priority tasks for the international Antarctic community is drilling and studying old Antarctic ice with age exceeding 1 million years in order to investigate possible reasons for the Mid-Pleistocene Transition. During the 2017–2018 austral season at Vostok Station, we carried out microscopic study of geometrical properties of the crystalline inclusions of air hydrates in ice core samples from boreholes 5G‑3 (Vostok) and DC2 (EPICA DC) in depth intervals where the age of the ice exceeded 400,000 years. The obtained data confirmed the existence of a robust linear relationship between the mean radius of the hydrates and the age of the ice in the bottom part of the East Antarctic ice sheet, and will be useful for further development of the new dating technique based on the phenomena of hydrate growth in polar ice. Preliminary, the age of the atmospheric ice bedded at Vostok at a depth of3538 m, inferred from the data on the size of the hydrates, amounts to 1.3±0.17 million years. The existence of ice older than 1 million years in the vicinity of Vostok implies that in the area of Ridge B, where the ice flow line which passes through Vostok Station originates, even older ice, with undisturbed stratigraphy, may exist. It would be desirable therefore to carry out a glacio-geophysical traverse to Ridge B in order to implement a detailed study of Dome B area aimed at identifying the most suitable site for a new deep drilling of the Antarctic ice sheet. Сделан краткий обзор деятельности международного антарктического сообщества по поиску древнего льда в Антарктиде. Приведены предварительные результаты работ, полученные на станции Восток в период 63-й Российской антарктической экспедиции, которые подтверждают, что возраст льда в уже полученном на станции керне превышает 1 млн лет. Сформулированы первоочередные задачи дальнейших исследований древнего антарктического льда на станции Восток и в районе Ледораздела В.