@article{oai:nipr.repo.nii.ac.jp:00002206,
 author = {Kelley,J.J. and Stanford,K. and Koci,B. and Wumkes, M. and Zagorodnov,V.},
 journal = {Memoirs of National Institute of Polar Research. Special issue},
 month = {Mar},
 note = {P(論文), The search for "zero defects" ice cores continues to challenge the ice coring and drilling community. No single drilling and coring device will fill all needs. Each project will have special requirements and will require an initial decision as to the most effective drilling system to be used as well as ensuring personal and environmental safety. PICO has developed several types of drilling and coring systems from a lightweight hand auger to more complicated electromechanical drills (dry and fluid-filled holes) with rock-penetrating capability and thermal drills. Logistics considerations are important, and a comparison is made between the drill types associated with system weight, expected power and drilling liquid requirements, and fuel consumption. Recent technological developments involve hot-water mechanical drilling, improvements in antifreeze and thermal drilling, the development of directional drilling, antifreeze dissolution drilling, and vibratory drilling.},
 pages = {24--40},
 title = {Ice coring and drilling technologies developed by the Polar Ice Coring Office},
 volume = {49},
 year = {1994}
}