Experimental research of ice cuttings transport by air while drilling of the snow-firn layer

• Main Authors: S. Ignatiev A., D. Vasilev A., A. Bolshunov V., M. Vasileva A., A. Ozhigin Yu., С. Игнатьев А., Д. Васильев А., А. Большунов В., М. Васильева А., А. Ожигин Ю.
• Other Authors: The team of authors would like to express their gratitude to the staff of the Vostok station of the 67th RAE and to the scientists of LIKOS Alexey Ekaykin and Irina Alekhina, for their assistance in carrying out the experimental work. We also thank all the reviewers for their insightful comments on our work and helped us to improve the paper substantially. The research was performed at the expense of the subsidy for the state assignment in the field of scientific activity for 2022 № FSRW-2021-0011., Коллектив авторов выражает благодарность персоналу станции Восток в сезоне 67 РАЭ и научным сотрудникам ЛИКОС Алексею Екайкину и Ирине Алёхиной за оказанное содействие в проведении экспериментальных работ. Мы также благодарим всех рецензентов за их конструктивные комментарии к нашей работе, которые помогли существенно улучшить статью. Исследование выполнено с помощью субсидии на выполнение государственного задания в сфере научной деятельности на 2022 г. № FSRW-2021- 0011.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2023
• Subjects: Central Antarctica;air drilling;ice cuttings;critical speed;suspension velocity;core;snow;firn; Центральная Антарктида;бурение с воздухом;ледяной шлам;критическая скорость;скорость витания;керн;снег;фирн; Antarctic; Greenland; Rae; Vostok Station; Annals of Glaciology; Antarc*; Antarctica; Arctic; glacier; Polar Science; Антарктида
• Online Access: https://ice-snow.igras.ru/jour/article/view/1158; https://doi.org/10.31857/S2076673423010076

The snow-firn layer of the glaciers of Antarctica and Greenland contains data on the composition of the atmosphere in the past, volcanic eruptions, forest fires, anthropogenic pollution, and many other unique information. Nowadays, core drilling methods are widely used for sampling the snow-firn layer. Due to numerous complications (loss of air circulation, drill bit sticking, ice balling up, etc.), air ice drilling is not wide spread, yielding in productivity and reliability to thermal and auger drilling methods. However, core barrel drilling with reverse bottom-hole air circulation is a promising technology for drilling the glaciers of Antarctica and Greenland. However, core drilling with reverse bottom-hole air circulation is a promising technology for drilling Antarctic and Greenland glaciers. The authors suggest that this technology, if successfully implemented, will significantly exceed the currently used methods of drilling the upper layers of the glacier. Taking into account the failures of previous projects of core drilling with air, it was decided to conduct research in the conditions of Central Antarctica in order to substantiate the design parameters of the new drill. During 67th Russian Antarctic Expedition (RAE) experimental studies of ice cuttings air transportation while drilling of the snow-firn layer were conducted at Vostok station. In the course of the experimental studies, the VK-22 borehole was drilled to a depth of 30 m with full core and ice cuttings sampling. According to the selected probes, the dependences of the change in the density of the snow-firn layer, bulk density and fractional composition of ice cuttings on the depth of occurrence were established. By using the experimental facility, the suspension velocity (critical speed in drilling) of ice particles of various sizes and shapes was found for the first time. Directions for further research and ways to improve the experimental facility are proposed, which are planned to be implemented in the season of the 68th RAE В целях ...