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

2021 ◽  
pp. 1-17
Author(s):  
Paul G. D. Anker ◽  
Keith Makinson ◽  
Keith W. Nicholls ◽  
Andrew M. Smith
Keyword(s):  
Modular Design ◽  
Hot Water ◽  
Extensive Experience ◽  
Subglacial Environment ◽  
Access Hole ◽  
Ice Stream ◽  
Drilling Operations ◽  
Water Recirculation ◽  
Field Season ◽  
Drill System

Abstract 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.

A microbiologically clean strategy for access to the Whillans Ice Stream subglacial environment

2013 ◽  
Vol 25 (5) ◽  
pp. 637-647 ◽  
Author(s):  
John C. Priscu ◽  
Amanda M. Achberger ◽  
Joel E. Cahoon ◽  
Brent C. Christner ◽  
Robert L. Edwards ◽  
...  
Keyword(s):  
Microbial Contamination ◽  
Hot Water ◽  
Ice Dynamics ◽  
Ross Ice Shelf ◽  
Subglacial Environment ◽  
West Antarctic ◽  
Ice Stream ◽  
Whillans Ice Stream ◽  
Hydrological System ◽  
Drilling Operations

AbstractThe Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project will test the overarching hypothesis that an active hydrological system exists beneath a West Antarctic ice stream that exerts a major control on ice dynamics, and the metabolic and phylogenetic diversity of the microbial community in subglacial water and sediment. WISSARD will explore Subglacial Lake Whillans (SLW, unofficial name) and its outflow toward the grounding line where it is thought to enter the Ross Ice Shelf seawater cavity. Introducing microbial contamination to the subglacial environment during drilling operations could compromise environmental stewardship and the science objectives of the project, consequently we developed a set of tools and procedures to directly address these issues. WISSARD hot water drilling efforts will include a custom water treatment system designed to remove micron and sub-micron sized particles (biotic and abiotic), irradiate the drilling water with germicidal ultraviolet (UV) radiation, and pasteurize the water to reduce the viability of persisting microbial contamination. Our clean access protocols also include methods to reduce microbial contamination on the surfaces of cables/hoses and down-borehole equipment using germicidal UV exposure and chemical disinfection. This paper presents experimental data showing that our protocols will meet expectations established by international agreement between participating Antarctic nations.

scholarly journals The BAS ice-shelf hot-water drill: design, methods and tools

2014 ◽  
Vol 55 (68) ◽  
pp. 44-52 ◽  
Author(s):  
Keith Makinson ◽  
Paul G.D. Anker
Keyword(s):  
Modular Design ◽  
Sea Water ◽  
Sediment Cores ◽  
Hot Water ◽  
Ice Shelf ◽  
Water Conductivity ◽  
Ice Shelves ◽  
Field Season ◽  
Temperature Depth

AbstractThe 2011/12 Antarctic field season saw the first use of a new British Antarctic Survey (BAS) ice-shelf hot-water drill system on the Larsen C and George VI ice shelves. Delivering 90 L min−1 at 80°C, a total of five holes >30 cm in diameter at three locations were successfully drilled through almost 400 m of ice to provide access to the underlying ocean, including the first access beneath the Larsen C ice shelf. These access holes enabled the deployment of instruments to measure sea-water conductivity, temperature, depth and microstructure, the collection of water samples and up to 2.9 m long sediment cores, before long-term oceanographic moorings were deployed. The simple modular design allowed for Twin Otter aircraft deployment, rapid assembly and commissioning of the system, which proved highly reliable with minimal supervision. A number of novel solutions to various operational sub-ice-shelf profiling and mooring deployment issues were successfully employed through the hot-water drilled access holes to aid the positioning, recovery and deployment of instruments. With future activities now focusing on the Filchner–Ronne Ice Shelf, the drill has been upgraded from its current 500 m capability to 1000 m with additional drill hose and further generator, pumping and heating modules.

scholarly journals Developing a hot-water drill system for the WISSARD project: 1. Basic drill system components and design

2014 ◽  
Vol 55 (68) ◽  
pp. 285-297 ◽  
Author(s):  
Frank R. Rack ◽  
Dennis Duling ◽  
Daren Blythe ◽  
Justin Burnett ◽  
Dar Gibson ◽  
...  
Keyword(s):  
Hot Water ◽  
West Antarctica ◽  
Initial Field ◽  
Subglacial Lake ◽  
Basal Ice ◽  
Science Management ◽  
Field Season ◽  
University Of Nebraska Lincoln ◽  
Subglacial Lake Whillans ◽  
Drill System

AbstractA new, clean, hot-water drill system (HWDS) was developed by the Science Management Office, University of Nebraska-Lincoln, for use in the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project to gain access to Subglacial Lake Whillans beneath ∼800 m of ice in West Antarctica. One primary borehole was drilled into the basal ice environment of Subglacial Lake Whillans during the initial field season in 2012/13. This paper describes the process of designing, fabricating, assembling, shipping, testing, commissioning and traversing the WISSARD HWDS leading up to the first scientific use of the system.

scholarly journals An assessment of deep hot-water drilling as a means to undertake direct measurement and sampling of Antarctic subglacial lakes: experience and lessons learned from the Lake Ellsworth field season 2012/13

2014 ◽  
Vol 55 (65) ◽  
pp. 59-73 ◽  
Author(s):  
Martin J. Siegert ◽  
Keith Makinson ◽  
David Blake ◽  
Matt Mowlem ◽  
Neil Ross
Keyword(s):  
Direct Measurement ◽  
Lessons Learned ◽  
Hot Water ◽  
Future Research ◽  
West Antarctica ◽  
Subglacial Lake ◽  
Subglacial Environment ◽  
Field Season ◽  
Subglacial Lakes ◽  
The Uk

AbstractIn the early hours of 25 December 2012, an attempt to explore Subglacial Lake Ellsworth, West Antarctica, using a specially designed hot-water drill, was halted. This UK project, involving several universities, the British Antarctic Survey and the National Oceanography Centre, had been in planning for 10 years. The project developed a full blueprint for subglacial lakes research, involving access to the subglacial environment through deep drilling, direct measurement and sampling of water and sediment by the construction of a probe and sediment corer, and environmental protocols to ensure cleanliness in line with international agreements on stewardship and protection of subglacial systems. Drilling was ceased after the main borehole failed to link with a subsurface cavity of water, built up over ∽40 hours. Without this link, insufficient water was available to continue drilling downwards to the lake, ∽3000 m beneath the surface. On return to the UK, an external review of the programme was undertaken to formally assess the reasons for the fieldwork failure, and to make recommendations on the modifications necessary for success. From this review, the Lake Ellsworth programme formulated a pathway along which a second attempt to explore the lake can be developed. Here details of the Lake Ellsworth field experiment, the circumstances that led to its failure and the corrections required are presented. Hot-water drilling is still regarded as the only feasible scheme for assuring clean access to the subglacial environment. The lessons learned from the Lake Ellsworth experience are substantial, however, and demonstrate that considerable technological and methodological advances are necessary for successful future research on subglacial lakes beneath thick (>2 km) ice.

Investigation of the Internal Blowout Accident Involving Overpressured Reservoirs: Case of CI-11 Well, Southern Tunisia

2021 ◽  
pp. 1-14
Author(s):  
Chaouki Khalfi ◽  
Riadh Ahmadi
Keyword(s):  
Water Flow ◽  
Water Table ◽  
Action Plan ◽  
Oil Field ◽  
Hot Water ◽  
Shallow Water Table ◽  
Ecological Consequences ◽  
Southern Tunisia ◽  
Drilling Operations ◽  
Recovery Program

Summary This study consists of an assessment of the ecological accident implicating the Continental Intercalaire-11 (CI-11) water well located in Jemna oasis, southern Tunisia. The CI-11 ecological accident manifested in 2014 with a local increase of the complex terminal (CT) shallow water table salinity and temperature. Then, this phenomenon started to spread over the region of Jemna, progressively implicating farther wells. The first investigation task consisted of logging the CI-11 well. The results revealed an impairment of the casing and cement of a huge part of the 9⅝ in. production casing. Historical production records show that the problems seem to have started in 1996 when a sudden production loss rate occurred. These deficiencies led to the CI mass-water flowing behind the casing from the CI to the CT aquifers. This ecological accident is technically called internal blowout, where water flows from the overpressurized CI groundwater to the shallower CT groundwater. Indeed, the upward CI hot-water flow dissolved salts from the encountered evaporite-rich formations of the Lower Senonian series, which complicated the ecological consequences of the accident. From the first signs of serious water degradation in 2014 through the end of 2018, several attempts have been made to regain control of annular upward water flow. However, the final CT groundwater parameters indicate that the problem is not properly fixed and communication between the two involved aquifers still persists. This accident is similar to the OKN-32 case that occurred in the Berkaoui oil field, southern Algeria, in 1986, and included the same CI and CT aquifers. Furthermore, many witnesses claim that other accidental communications are probably occurring in numerous deep-drilled wells in this region. Concludingly, Jemna CI-11, Berkaoui OKN-32, and probably many other similar accident cases could be developing regional ecological disasters by massive water resource losses. The actual situation is far from being under control and the water contamination risk remains very high. In both accidents, the cement bond failure and the choice of the casing point are the main causes of the internal blowout. Therefore, we recommend (1) a regional investigation and risk assessment plan that might offer better tools to predict and detect earlier wellbore isolation issues and (2) special attention to the cement bond settlement, evaluation, and preventative logging for existing wells to ensure effective sealing between the two vulnerable water table resources. Besides, in the CI-11 well accident, the recovery program was not efficient and there was no clear action plan. This increased the risk of action failure or time waste to regain control of the well. Consequently, we suggest preparing a clear and efficient action plan for such accidents to reduce the ecological consequences. This requires further technical detailed study of drilling operations and establishment of a suitable equipment/action plan to handle blowout and annular production accidents.

scholarly journals Modeling Antarctic subglacial lake filling and drainage cycles

2016 ◽  
Vol 10 (4) ◽  
pp. 1381-1393 ◽  
Author(s):  
Christine F. Dow ◽  
Mauro A. Werder ◽  
Sophie Nowicki ◽  
Ryan T. Walker
Keyword(s):  
Internal Controls ◽  
Water Volume ◽  
Lake Basin ◽  
Subglacial Lake ◽  
Subglacial Environment ◽  
Ice Surface ◽  
Ice Stream ◽  
Slow Moving ◽  
Lake Drainage ◽  
Subglacial Lakes

Abstract. The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to examine internal controls on the filling and drainage of subglacial lakes. Our model outputs suggest that the highly constricted subglacial environment of our idealized ice stream, combined with relatively high rates of water flow funneled from a large catchment, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water beneath the ice stream drives lake growth. As the water body builds up, it steepens the hydraulic gradient out of the overdeepened lake basin and allows greater flux. Eventually this flux is large enough to melt channels that cause the lake to drain. Lake drainage also depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

scholarly journals A low-cost autonomous rover for polar science

2019 ◽  
Author(s):  
Andrew O. Hoffman ◽  
Hans Christian Steen-Larsen ◽  
Knut Christianson ◽  
Christine Hvidberg
Keyword(s):  
Modular Design ◽  
Low Cost ◽  
Digital Elevation Models ◽  
Ice Core ◽  
Snow Accumulation ◽  
Spatiotemporal Variability ◽  
Dual Frequency ◽  
Ice Stream ◽  
Digital Elevation ◽  
Software Instrumentation

Abstract. We present the developmental considerations, design, and deployment of an autonomous modular terrestrial rover for ice-sheet exploration that is inexpensive, easy to construct, and allows for instrumentation customization. Total construction cost for this rover is less than $3000, approximately one tenth the cost of existing platforms, and it can be built using facilities frequently available at academic institutions (machine shop, 3D printer, open-source hardware and software). Instrumentation deployed on this rover can be customized; the rover presented in this study was equipped with a dual-frequency GPS receiver and a digital SLR camera for constructing digital elevation models using structure-from motion (SfM) photogrammetry. We deployed this prototype rover on the Northeast Greenland Ice Stream to map local variations in snow accumulation and surface topography. The rover conducted four autonomous missions based out of the East Greenland Ice Core Project (EGRIP) camp during July 2017, measuring surface elevation transects across the hazardous ice-stream shear margins. During these missions, the rover proved capable of driving over 20 km on a single charge with a drawbar pull of 25°N, sufficient to tow commercial ground-penetrating radars. The rover also acquired photographs that were subsequently used to construct digital elevation models of a site monitored for spatiotemporal variability in snow accumulation, demonstrating adequate stability for high-resolution imaging applications. Due to its low cost, low-power requirements, and simple modular design, mass deployments of this rover design are practicable. Furthermore, operation of the rover in hazardous areas circumvents substantial expense and risk to personnel associated with conventional, crewed deployments. Thus, this rover is an investigatory platform that enables direct exploration of polar environments considered too hazardous for conventional field expeditions.

scholarly journals Radar reflections reveal a wet bed beneath stagnant Ice Stream C and a frozen bed beneath ridge BC, West Antarctica

1998 ◽  
Vol 44 (146) ◽  
pp. 149-156 ◽  
Author(s):  
C. R. Bentley ◽  
N. Lord ◽  
C. Liu
Keyword(s):  
Radar Data ◽  
Ice Thickness ◽  
West Antarctica ◽  
Ice Streams ◽  
Ice Stream ◽  
Crossover Analysis ◽  
Automated Processing ◽  
Basal Reflection ◽  
Field Season ◽  
Ice Stream B

AbstractDigital airborne radar data were collected during the 1987-88 Antarctic field season in nine gridded blocks covering the downstream portions of Ice Stream B (6km spacing) and Ice Stream C (11 km spacing), together with a portion of ridge BC between them. An automated processing procedure was used for picking onset times of the reflected radar pulses, converting travel times to distances, interpolating missing data, converting pressure transducer readings, correcting navigational drift, performing crossover analysis, and zeroing rémanent crossover errors. Interpolation between flight-lines was carried out using the minimum curvature method.Maps of ice thickness (estimated accuracy 20 m) and basal-reflection strength (estimated accuracy 1 dB) were produced. The ice-thickness map confirms the characteristics of previous reconnaissance maps and reveals no new features. The reflection-strength map shows pronounced contrasts between the ice streams and ridge BC and between the two ice streams themselves. We interpret the reflection strengths to mean that the bed of Ice Stream C, as well as that of Ice Stream B, is unfrozen, that the bed of ridge BC is frozen and that the boundary between the frozen bed of ridge BC and the unfrozen bed of Ice Stream C lies precisely below the former shear margin of the ice stream.

scholarly journals A borehole camera system for imaging the deep interior of ice sheets

2002 ◽  
Vol 48 (163) ◽  
pp. 622-628 ◽  
Author(s):  
Frank Carsey ◽  
Alberto Behar ◽  
A. Lonne Lane ◽  
Vince Realmuto ◽  
Hermann Engelhardt
Keyword(s):  
Ice Sheets ◽  
Hot Water ◽  
Ice Streams ◽  
Camera System ◽  
West Antarctic ◽  
California Institute Of Technology ◽  
Deep Interior ◽  
Field Season ◽  
Institute Of Technology ◽  
Borehole Camera

AbstractThe design and first deployment is described for the Jet Propulsion Laboratory–California Institute of Technology ice borehole camera system for acquisition of down-looking and side-looking images in a borehole made by a hot-water drill. The objective of the system is to acquire images in support of studies of the basal dynamics and thermodynamics of West Antarctic ice streams. A few sample images, obtained during the 2000/01 Antarctic field season, are shown from the basal layers of Ice Stream C.

scholarly journals Mechanisms of fast flow in Jakobshavns Isbræ, West Greenland: Part I. Measurements of temperature and water level in deep boreholes

1993 ◽  
Vol 39 (131) ◽  
pp. 15-25 ◽  
Author(s):  
A. Iken ◽  
Κ. Echelmeyer ◽  
W. Harrison ◽  
M. Funk
Keyword(s):  
Water Level ◽  
Drainage System ◽  
Hot Water ◽  
Surface Velocity ◽  
Striking Difference ◽  
Relative Depth ◽  
Measured Temperature ◽  
Basal Ice ◽  
Ice Stream ◽  
Fast Flow

AbstractSeveral holes were drilled to depths of 1500–1630 m along a profile across Jakobshavns Isbræ, 50 km upstream from the calving front. Drilling was by hot water and required approximately 20 h. The holes were rapidly closed by refreezing, but it was possible to instrument them with thermistors and tilt sensors before this occurred.Near the margins of the ice stream the holes reached the bed and connected with the subglacial drainage system. Water-level changes recorded in these holes are discussed in terms of the basal hydraulic system. The temperature measurements show that the glacier is temperate-based. Moreover, extrapolation of a measured temperature profile and its curvature suggests that a temperate layer of substantial thickness may exist at the bed near the center of the ice stream. There is a striking difference in the shapes of temperature profiles measured at different locations: beneath the center line the temperature minimum is at a considerably smaller relative depth than near the margins, but it is nearly the same in magnitude (−22.1°C). This may indicate a disproportionately large vertical stretching of the basal ice in the center of the ice stream. Since the basal ice is warmer and much less viscous than the ice above, a thickening of that layer would cause a corresponding increase of surface velocity. We presume that this mechanism contributes to the fast flow of Jakobshavns Isbræ.

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