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Rapid Access Ice Drill is a new drilling technology capable of quickly accessing the glacial bed of Antarctic ice sheets, retrieving ice core and rock core samples, and providing boreholes for downhole logging of physical properties. Scientific goals include searching for old ice near the glacial bed and sampling subglacial bedrock. During field trials near McMurdo Station on a piedmont glacier at Minna Bluff in the 2019–20 austral summer, we successfully completed a 'top-to-bottom' operational sequence in three boreholes by (1) augering through firn, (2) creating a borehole packer seal in non-porous ice, (3) establishing fluid circulation, (4) quickly drilling a borehole in ice at penetration rates up to 1.2 m min−1, (5) acquiring a short ice core at depth, (6) penetrating the glacial bed at a depth of ~677 m, (7) recovering a 3.2 m core of ice, basal till and subglacial bedrock, (8) optically logging the borehole on wireline, (9) testing hydrofracture potential by overpressuring the borehole fluid and (10) operating in an environmentally benign yet rapid field mode. Minna Bluff testing, therefore, demonstrates the effectiveness of this integrated system to drill rapidly through thick ice and penetrate across the glacial bed to take cores of bedrock. [ABSTRACT FROM AUTHOR]

Over the course of the 2014/15 and 2015/16 austral summer seasons, the South Pole Ice Core project recovered a 1751m 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. [ABSTRACT FROM AUTHOR]

An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highestresolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice, which was likely due to site characteristics and, to a lesser extent, to drill technology and core handling procedures. [ABSTRACT FROM AUTHOR]

The Winkie Drill is an agile, commercially available rock coring system. The U.S. Ice Drilling Program has modified a Winkie Drill for subglacial rock and ice/rock interface coring, as well as drilling and coring access holes through ice. The original gasoline engine was replaced with an electric motor though the two-speed gear reducer and Unipress hand feed system were maintained. Using standard aluminum AW34 drill rod (for 33.5mm diameter core), the system has a depth capability of 120 m. The drill uses forward fluid circulation in a closed loop system. The drilling fluid is Isopar K, selected for favorable properties in polar environment. When firn or snow is present at the drill site, casing with an inflatable packer can be deployed to contain the drill fluid. The Winkie Drill will operate from sea level to high altitudes and operation results in minimal environmental impact. The drill can be easily and quickly assembled and disassembled in the field by two people. All components can be transported by Twin Otter or helicopter to the field site. [ABSTRACT FROM AUTHOR]

Drilling the WDC06A borehole at the West Antarctic Ice Sheet (WAIS) Divide with the Deep Ice Sheet Coring (DISC) drill began in December 2007 and was successfully completed in December 2011 to a depth of 3405 m. The design and construction of a replicate coring system for use with the existing DISC drill began in 2010. In January 2012, the new replicate coring system was tested in the parent borehole at WAIS Divide. While a full deviation was not completed during the test period, much was learned about the mechanical, electrical and operational aspects of the system. Extensive testing and modifications were done over the northern/boreal summer to prepare the system for the upcoming and final season of the project. Further tuning of the system continued during the 2012/13 field season at WAIS Divide. This paper identifies the issues found with the system during the initial test season and discusses solutions, methods and testing done to arrive at an operational system. [ABSTRACT FROM AUTHOR]

The replicate ice-coring system was developed by Ice Drilling Design and Operations (IDDO) for the US National Science Foundation. The design of the system leverages the existing infrastructure of the deep ice-sheet coring (DISC) drill to create a steerable drill capable of recovering replicate core at any targeted depth in an existing borehole. Critical requirements of the system include: collecting up to 400 m of core from the high side of an open hole; maintaining access to the entire borehole for logging tools; collecting up to four cores at a single depth; and operating to a depth of 4000 m at -55°C and 34 MPa. The system was developed and tested from 2010 through 2012 and integrates several new mechanical subsystems, including two electromechanical actuators capable of pushing the sonde to any targeted azimuth, new reduced diameter core and screen barrels made from off-the-shelf casing tube, and new cutter heads optimized for the multiple stages of the replicate coring procedure. The system was successfully deployed at West Antarctic Ice Sheet (WAIS) Divide in the 2012/13 field season, recovering 285 m of core from five intentional deviations at four target depths. [ABSTRACT FROM AUTHOR]

Many of the ice-coring objectives in the Ice Drilling Program Office (IDPO) Long Range Science Plan, such as those in the International Partnerships in Ice Core Sciences (IPICS) 2k array and 40k network, are attainable in many locations with an intermediate depth drill (IDD) that can collect core from a fluid-filled hole down to 1500 m depth. The Ice Drilling Design and Operations (IDDO) group has designed and is in the process of building an agile IDD to meet this objective. The drill tent, power distribution and core-processing systems are an integral part of the IDD, which can be deployed by small aircraft and assembled by hand to minimize logistic requirements. The new drill system will be ready for testing in Greenland beginning in late spring 2014. The first production drilling is scheduled for the 2014/15 field season at the South Pole. [ABSTRACT FROM AUTHOR]

The deep ice-sheet coring (DISC) drill was used for production ice-core drilling at WAIS Divide in Antarctica for six field seasons between 2007 and 2013. Continuous ice-core samples were obtained between the snow surface and 3405 m depth. During the 2012/13 austral summer, the DISC drill's newly designed replicate ice-coring system was utilized to collect nearly 285 m of additional high-quality core samples at depths of high scientific interest. Annual progress graphs are described, as well as milestones achieved over the course of the project. Drilling operations, challenges encountered, drill fluid usage, drilling results, and the drill crew's experiences with the DISC drill and replicate coring system during production drilling are described and discussed in detail. Core-processing operations are described briefly, as well as the logistical undertaking of the DISC drill's deployment to Antarctica. [ABSTRACT FROM AUTHOR]

The Blue Ice Drill (BID) is a large-diameter agile drill system designed by the Ice Drilling Design and Operations group of the University of Wisconsin-Madison to quickly core-clean 241 mm diameter ice samples from near-surface sites. It consists of a down-hole motor/gear reducer rotating a coring cutter and core barrel inside an outer barrel for efficient cuttings transport in solid ice. A variable-frequency drive and custom control box regulates electrical power to the drill. Torque reaction is accomplished on the surface via handles attached to a torsion stem. Core recovery is achieved with either core dogs in the sonde or with a separate core recovery tool. All down-hole tools are suspended on a collapsible tripod via ropes running on a capstan winch. The BID is operated by a minimum of two people and has been used successfully during two seasons of coring on a blue ice area of Taylor Glacier, Antarctica. An updated version of the drill system, BID-Deep, has been designed to recover cores to depths up to 200 m. [ABSTRACT FROM AUTHOR]

The drilling of a deep borehole in ice is an undertaking that spans several seasons. Over recent decades such drilling has become widespread in both polar regions. Owing to the remoteness of the drill sites, considerable cost is associated with the drilling of a deep borehole of several thousand meters. The replicate coring system allows re-drilling of ice core at select depths within an existing parent borehole. This effectively increases the yield of the existing borehole and permits re-sampling of ice in areas of high scientific value. The replicate coring system achieves this through the combination of actuators, motors, sensors and a computerized control system. The replicate coring drill is a further development of the deep ice-sheet coring (DISC) drill, extending the capabilities of the DISC drill to include replicate coring. [ABSTRACT FROM AUTHOR]

After the NEEM (Greenland) deep ice-core drilling was declared terminated with respect to developing stratigraphic climate reconstructions, efforts were turned toward collecting basal icesheet debris and, if possible, drilling into the bedrock itself. In 2010, several meters of banded debrisrich ice were obtained under normal ice-drilling operations with the NEEM version of the Hans Tausen (HT) drill, but further penetration was obstructed by a rock in the path of the drill head at 2537.36 m. During short campaigns in 2011 and 2012, attempts were made to penetrate further using various reinforced ice cutters mounted on the HT drill head, tailored to cut through rock. These had some success in penetrating coarse material, but produced severely damaged cutters. Additionally a 51 mm diameter diamond cutting tipped rock drill was adapted to fit the NEEM drill. With this device, several additional meters of core containing subglacial sediments, rocks and rock fragments were collected. With these tools 1.39 m of additional material were obtained during the 2011 field season, and 7.1 m during 2012. Subglacial water refreezing into the newly formed borehole hindered further penetration, and the bedrock interface was not reached before final closure of the NEEM Camp. [ABSTRACT FROM AUTHOR]

On 1 December 2011 the West Antarctic Ice Sheet (WAIS) Divide ice-core project reached its final depth of 3405 m. The WAIS Divide ice core is not only the longest US ice core to date, but is also the highest-quality deep ice core, including ice from the brittle ice zone, that the US has ever recovered. The methods used at WAIS Divide to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the US National Ice Core Laboratory (NICL) and the methods used to process and sample the ice at the NICL are described and discussed. [ABSTRACT FROM AUTHOR]