Ice core drilling on a high-elevation accumulation zone of Trambau Glacier in the Nepal Himalaya

We drilled an 81.2-m-long ice core in the accumulation area (5860 m a.s.l.) of Trambau Glacier in the Rolwaling region during October–November 2019. The drilling operation was conducted with a lightweight electro-mechanical drill system after two reconnaissance fieldworks in 2017 and 2018, during which two shallow firn cores were drilled with a hand auger. The drill system and ice core samples were transported by helicopters at a high elevation of 6000 m a.s.l. A further challenging issue was the ice core transportation between Nepal and Japan, as no regular commercial flight was available for the frozen samples. The addition of dry ice imported from India immediately prior to leaving Nepal allowed the ice core samples to be successfully transported to a cold room in Japan, and remain in a frozen state. Stratigraphic observations during the drilling operation suggest the drill site has been affected by melting and refreezing.

Shallow hot-point drill system for active layer temperature measurement along Zhongshan–Dome A traverse, Antarctica

In glaciology, snow–firn temperature at 10 m is considered a representation of the mean annual air temperature at the surface (MAAT) of the studied site. Although MAAT is an important parameter in ice-sheet investigations, it has not been widely measured in Antarctica. To measure the 10 m snow–firn temperature in Antarctica, a shallow hot-point drill system is designed. In this simple and lightweight system, a hot-point drill can melt boreholes with a diameter of 34 mm in the snow–firn to a depth of 30 m and a temperature sensors string can measure the borehole temperature precisely. In the 2018/19 field season, 16 boreholes along the Zhongshan–Dome A traverse were drilled, and the borehole temperature was measured. Although certain problems existed pertaining to the hot-point drill, a total depth of ~244 m was successfully drilled at an average penetration rate of ~10 m h−1. After borehole drilling, ~12–15 h were generally required for the borehole to achieve thermal equilibrium with the surroundings. Preliminary results demonstrated that the 10 m snow–firn temperature along the traverse route was affected by the increasing altitude and latitude, and it decreased gradually with an increase in the distance from Zhongshan station.

The BEAMISH hot water drill system and its use on the Rutford Ice Stream, Antarctica

During the 2018/19 Antarctic field season, the British Antarctic Survey (BAS) Basal conditions on Rutford Ice Stream: BEd Access, Monitoring and Ice Sheet History’ (BEAMISH) project drilled three holes through the Rutford Ice Stream, West Antarctica. At up to 2154 m, these are the deepest hot water drilled subglacial access holes yet created, enabling the recovery of sediment from the subglacial environment, and instrumenting the ice stream and its bed. The BEAMISH hot-water drill system was built on extensive experience with the BAS ice shelf hot-water drill and utilises many identical components. With up to 1 MW of heating power available, the hot water drill produces 140 L min−1 of water at 85°C to create a 300 mm diameter access hole to the base of the ice stream. New systems and processes were developed for BEAMISH to aid critical aspects of deep access drilling, most notably the creation of cavities interlinking boreholes at 230 m below the surface and enabling water recirculation throughout the deep drilling operations. The modular design of the BEAMISH drill offers many benefits in its adaptability, redundancy, and minimal logistical footprint. These design features can easily accommodate the modifications needed for future deep, clean access hole creation in the exploration of subglacial environments.

RAM-2 Drill system development: an upgrade of the Rapid Air Movement Drill

Significant upgrades to the Rapid Air Movement (RAM) Drill were developed and tested by the US Ice Drilling Program in 2016 through 2020 for the U.S. National Science Foundation. The design of the system leverages the existing infrastructure of the RAM Drill with the goal of greatly reducing the logistical burden of deploying the drill while maintaining the ability to drill an access hole in firn and ice to 100 m in 40 min or less. In this paper, characteristics of the drill are described, along with a description of the drill performance during the testing at Raven Camp in Greenland and at WAIS Divide Camp in Antarctica.

Agile Sub-Ice Geological (ASIG) Drill development and Pirrit Hills field project

A new drilling system was developed by the US Ice Drilling Program (IDP) to rapidly drill through overlying ice to collect subglacial rock cores. The Agile Sub-Ice Geological (ASIG) Drill system is capable of drilling up to 700 m of ice in a continuous manner. Intermittent ice core samples can be taken as needed. Ten-plus meters of subglacial bedrock and unconsolidated, frozen sediment cores can be drilled with wireline core retrieval. The functionality of the drill system was demonstrated in 2016–17 at the Pirrit Hills, Antarctica where 8 m of high-quality, continuous granite core was retrieved beneath 150 m of ice. The particulars of the drill system development, features and performance are discussed.

Drilling operations for the South Pole Ice Core (SPICEcore) project

Over the course of the 2014/15 and 2015/16 austral summer seasons, the South Pole Ice Core project recovered a 1751 m deep ice core at the South Pole. This core provided a high-resolution record of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. The drilling and core processing were completed using the new US Intermediate Depth Drill system, which was designed and built by the US Ice Drilling Program at the University of Wisconsin–Madison. In this paper, we present and discuss the setup, operation, and performance of the drill system.