Ice Drilling Performance in the Firn Drill Layer at the South Pole

Abstract

This study aims to evaluate the performance of ice drilling in the firn layer at the South Pole, which is a critical component of the IceCube Upgrade Project for deploying neutrino detectors beneath the Antarctic ice sheet. Field tests conducted during the summer of 2024–2025 revealed that the balance between drill head load and drilling depth significantly affects borehole deviation and overall drilling efficiency. Proper control of standing load and vertical drill speed was found to reduce borehole misalignment and mitigate drill head jamming—particularly in the highly porous firn layer. The results indicated that asymmetrical loading conditions could lead to drill tilt and increased difficulty in retracting the drill. To enhance performance, this study proposes load-depth balancing strategies, seasonally optimized drilling windows, and the integration of mechanical and thermal drilling techniques. The insights gained provide practical guidance for improving ice drilling technologies under extreme polar conditions, supporting advancements in neutrino physics.