scholarly journals Air reverse circulation at the hole bottom in ice-core drilling

2019 ◽  
Vol 65 (249) ◽  
pp. 149-156 ◽  
Author(s):  
ZHENGYI HU ◽  
PAVEL TALALAY ◽  
ZHICHUAN ZHENG ◽  
PINLU CAO ◽  
GUITAO SHI ◽  
...  
Keyword(s):  
High Efficiency ◽  
Ice Core ◽  
Ice Cores ◽  
Test Results ◽  
Core Drilling ◽  
Low Energy Consumption ◽  
Reverse Circulation ◽  
Drilling System ◽  
Conventional Drilling ◽  
Hole Bottom

ABSTRACTIce-core drilling to depths of 200–300 m is an important part of research studies concerned with paleoclimate reconstruction and anthropogenic climate change. However, conventional drilling methods face difficulties due to firn permeability. We have developed an electromechanical ice-core drill with air reverse circulation at the hole bottom. We believe that the new drilling system will recover ice cores faster than shallow auger drills, with high efficiency and low energy consumption. The theoretically estimated up-hole speed of the airflow should be not <7.7 m s−1 to allow proper removal of ice cuttings from the borehole bottom. The computer simulation and test results showed that the design of the new ice-coring drill is feasible. The maximum allowed penetration rate depends by square law on airflow.

scholarly journals A hot-water ice-coring drill

2000 ◽  
Vol 46 (153) ◽  
pp. 341-345 ◽  
Author(s):  
H. Engelhardt ◽  
B. Kamb ◽  
R. Bolsey
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Hot Water ◽  
New Method ◽  
Core Drilling ◽  
Water Ice ◽  
Water Jets

AbstractA new method of ice-core drilling uses an annulus of hot-water jets to melt out a cylindrical ice core. This lightweight device used in combination with a fast hot-water drill can quickly obtain ice cores from any depth.

Theory calculation and testing of air injection parameters in ice core drilling with air reverse circulation

Polar Science ◽  
2018 ◽  
Vol 17 ◽  
pp. 23-32 ◽  
Author(s):  
Pinlu Cao ◽  
Miaomiao Liu ◽  
Zhuo Chen ◽  
Baoyi Chen ◽  
Qi Zhao
Keyword(s):  
Ice Core ◽  
Air Injection ◽  
Core Drilling ◽  
Injection Parameters ◽  
Reverse Circulation ◽  
Theory Calculation

scholarly journals Orthogonal experimental research on the structural parameters of a novel drill bit used for ice core drilling with air reverse circulation

2019 ◽  
Vol 65 (254) ◽  
pp. 1011-1022 ◽  
Author(s):  
Pinlu Cao ◽  
Qi Zhao ◽  
Zhuo Chen ◽  
Hongyu Cao ◽  
Baoyi Chen
Keyword(s):  
Structural Parameters ◽  
Ice Core ◽  
Influential Factor ◽  
Dominant Factor ◽  
Orthogonal Experimental Design ◽  
Drill Bit ◽  
Entrainment Ratio ◽  
Core Drilling ◽  
Helical Angle ◽  
Reverse Circulation

AbstractA new type of ice core drill bit, designed with a vane swirler, was developed for ice core drilling with air reverse circulation. An orthogonal experimental design method was employed to investigate the effects of the swirler structure parameters on the reverse circulation performance of the drill bit including helical angle, number of blades, blade length and blade central angle, etc. The entrainment ratio was used to evaluate the reverse circulation effectiveness of the drill bit. The results show that the helical angle is the dominant factor regardless of whether or not the flushing nozzles are part of the design of the drill bit. The number of blades is the least important factor for the drill bit designed with the flushing nozzles (referred to as drill bit I), while the outlet area of the swirling slot is the least influential factor for the drill bit without flushing nozzles (referred to as drill bit П). In addition, the appearance of the ice core has a certain effect on the air reverse circulation for both drill bits. Within the ranges of this study, the optimal structure of the drill bit was determined based on the range analysis of the orthogonal design.

scholarly journals Mapping the suitability for ice-core drilling of glaciers in the European Alps and the Asian High Mountains

2017 ◽  
Vol 64 (243) ◽  
pp. 12-26 ◽  
Author(s):  
ROBERTO GARZONIO ◽  
BIAGIO DI MAURO ◽  
DANIELE STRIGARO ◽  
MICOL ROSSINI ◽  
ROBERTO COLOMBO ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Ice Core ◽  
Ice Cores ◽  
Weight Of Evidence ◽  
European Alps ◽  
High Mountains ◽  
Mountain Glacier ◽  
Past Climate ◽  
Core Drilling ◽  
Mountain Glaciers

ABSTRACTIce cores from mid-latitude mountain glaciers provide detailed information on past climate conditions and regional environmental changes, which is essential for placing current climate change into a longer term perspective. In this context, it is important to define guidelines and create dedicated maps to identify suitable areas for future ice-core drillings. In this study, the suitability for ice-core drilling (SICD) of a mountain glacier is defined as the possibility of extracting an ice core with preserved stratigraphy suitable for reconstructing past climate. Morphometric and climatic variables related to SICD are selected through literature review and characterization of previously drilled sites. A quantitative Weight of Evidence method is proposed to combine selected variables (i.e. slope, local relief, temperature and direct solar radiation) to map the potential drilling sites in mid-latitude mountain glaciers. The method was first developed in the European Alps and then applied to the Asian High Mountains. Model performances and limitations are discussed and first indications of new potential drilling sites in the Asian High Mountains are provided. Results presented here can facilitate the selection of future drilling sites especially on unexplored Asian mountain glaciers towards the understanding of climate and environmental changes.

scholarly journals Intermediate-depth ice coring of high-altitude and polar glaciers with a lightweight drilling system

2005 ◽  
Vol 51 (174) ◽  
pp. 491-501 ◽  
Author(s):  
V. Zagorodnov ◽  
L.G. Thompson ◽  
P. Ginot ◽  
V. Mikhalenko
Keyword(s):  
High Altitude ◽  
Drilling Fluid ◽  
Ice Core ◽  
Ice Cores ◽  
Cutting Fluid ◽  
Intermediate Depth ◽  
Ice Cap ◽  
Dust Composition ◽  
Electric Drill ◽  
Drilling System

AbstractA total of 11 ice cores to a maximum depth of 460 m have been obtained over the past 3 years from high-altitude glaciers on the saddle of Mount Bona and Mount Churchill in Alaska (designated B–C), and on Quelccaya ice cap and Nevado Coropuna in Peru. Ice coring was conducted using an intermediate-depth drilling system. The system includes an electromechanical drill (EMD) and an ethanol thermal electric drill (ETED). The EMD permitted an average ice-core production rate (ICPR) of 7.0 m h−1 down to 150 m. An average ICPR of 2 m h−1 to 460 m depth was possible with the ETED. The quality of the B–C ice cores is better than that of cores previously drilled with an EMD and ETED system. A new cutter design, drilling with a lubricant/cutting fluid and a new anti-torque assembly were tested in the laboratory and in glacier boreholes. We examine the performance of the drills in cold and temperate ice and in clean and particle-laden ice. The influence of the ethanol drilling fluid on ice-core isotopic, ionic and dust composition is discussed.

scholarly journals A new thermal drilling system for high-altitude or temperate glaciers

2014 ◽  
Vol 55 (68) ◽  
pp. 131-136 ◽  
Author(s):  
Margit Schwikowski ◽  
Theo M. Jenk ◽  
Dieter Stampfli ◽  
Felix Stampfli
Keyword(s):  
Melting Point ◽  
Liquid Water ◽  
Ice Core ◽  
Ice Cores ◽  
High Elevation ◽  
Swiss Alps ◽  
Ice Melting ◽  
Thermal Drilling ◽  
Drilling System ◽  
Core Production

AbstractFor ice-core drilling on high-elevation glaciers, lightweight and modular electromechanical (EM) drills are used to allow for transportation by porters or pack animals. However, application of EM drills is constrained to glaciers with temperatures well below the ice melting point. When drilling into temperate ice, liquid water accumulates in the borehole, hindering chip transport, filling the chip barrel and finally blocking the drill. Drilling into near-temperate ice is also problematic as pressure-induced melting can cause refreezing of meltwater on the drill which then easily gets stuck in the borehole. We developed a thermal drill compatible with the Fast Electromechanical Lightweight Ice Coring System (FELICS). The melting element consists of a coil heater, molded in an aluminum crown. Using the combined mechanical and thermal drill we obtained a 101 m surface-to-bedrock ice core from temperate Silvrettagletscher, Swiss Alps. The borehole with temperatures around 0°C was filled with meltwater. Power was supplied by two 2kW gasoline generators consuming a total of 70 L of alkylate fuel. Ice-core production rate was 1.8 mh−1. The drill produced non-fractured ice cores of excellent quality with a length of 70 cm and a diameter of 75–80 mm.

scholarly journals Deep ice core drilling to a depth of 3035.22 m at Dome Fuji, Antarctica in 2001–07

2020 ◽  
pp. 1-11
Author(s):  
Hideaki Motoyama ◽  
Akiyoshi Takahashi ◽  
Yoichi Tanaka ◽  
Kunio Shinbori ◽  
Morihiro Miyahara ◽  
...  
Keyword(s):  
Ice Core ◽  
Austral Summer ◽  
Storage Efficiency ◽  
Core Drilling ◽  
Pilot Hole ◽  
Core Length ◽  
Drilling Data ◽  
Antarctic Research ◽  
Drilling System ◽  
Small Holes

Abstract The Japanese second deep ice coring project was carried out at Dome Fuji, Antarctica. Following the drilling of the pilot hole in 2001, deep ice core drilling led by the Japanese Antarctic Research Expedition (JARE) was conducted over four austral summer seasons, beginning with the 2003/04 season and reached a depth of 3035.22 m near the bedrock in January 2007. The new drill was designed and developed with the goals of (1) solving the problems encountered during the first JARE deep coring drill and (2) achieving more efficient drilling. In particular, the maximum core length that can be drilled at one time was increased from 2.30 m to 3.84 m and the chip storage efficiency was enhanced by a special pipe with many small holes. This paper gives an outline of the improved drilling system, the progress of drilling and various drilling data.

Ultrasonic velocity experiments on ice cores to complement fabric measurements

2021 ◽  
Author(s):  
Sebastian Hellmann ◽  
Johanna Kerch ◽  
Melchior Grab ◽  
Henning Löwe ◽  
Andreas Bauder ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Crystal Orientation ◽  
Ice Core ◽  
Ice Cores ◽  
Ultrasonic Waves ◽  
Thin Sections ◽  
Core Drilling ◽  
Core Samples ◽  
Ultrasonic Measurements ◽  
Polarised Light

&lt;p&gt;The ice crystal structure and in particular the crystal orientation fabrics (COF) provide valuable information about the deformation history of ice sheets and glaciers. Therefore, COF analysis has been among the standard measurement techniques for most deep ice core drilling projects in the last three decades. The analysis depends on carefully prepared thin sections of ice that are measured with cross-polarised light microscopy or electron backscattering and diffraction (EBSD). The preparation of thin sections is labour-intensive and therefore only a discrete number of samples along the ice core is usually analysed. Geophysical methods such as ultrasonic sounding along the ice core could be employed to complement the discrete fabric data by providing data to fill the gaps. A suitable method needs to be reasonably fast, ideally non-invasive and provides unambiguous information in combination with the established methods.&lt;/p&gt;&lt;p&gt;In our study, we demonstrate the feasibility of such ultrasonic experiments applied to an ice core to support the approved cross-polarised light microscopy method. Point-contact transducers transmitted ultrasonic waves into ice core samples from a temperate glacier. X-ray computer tomography measurements provide the required information to consider the effect of a two-phase medium (ice and air bubbles) in a porosity correction of the velocity. We determined the azimuthal variation of the seismic velocity. This variation is a result of seismic anisotropy due to the crystal orientation within the ice core volume. The measurements can be acquired within minutes and do not require an extensive preparation of ice samples.&lt;/p&gt;&lt;p&gt;In addition, the COF of adjacent ice core samples was measured with cross-polarised light spectroscopy. From this, we derived the elasticity tensor and finally calculated the associated seismic velocities for the same azimuth and inclination angle as for the ultrasonic experiments. We compare these two velocity profiles and discover a significant discrepancy in presence of large ice grains. However, with an increasing number of ice grains both methods provide similar results. Although the ultrasonic measurements reveal some ambiguities, these can be resolved when considering the information derived from the standard analysis.&lt;/p&gt;&lt;p&gt;We conclude that ultrasonic measurements along the ice core are suitable to support the established COF analysis for sufficiently small grains as found in polar cores. We recommend further exploration of the potential of the presented technique as it provides both the chance to obtain a continuous fabric profile and a direct link to large-scale seismic measurements in the vicinity of ice core drilling sites.&lt;/p&gt;

scholarly journals Deep ice-core drilling to 800 m at Dome A in East Antarctica

2021 ◽  
pp. 1-12
Author(s):  
Zhengyi Hu ◽  
Guitao Shi ◽  
Pavel Talalay ◽  
Yuansheng Li ◽  
Xiaopeng Fan ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
East Antarctica ◽  
Hole Drilling ◽  
Dome A ◽  
Core Drilling ◽  
Pilot Hole ◽  
The Troubles ◽  
Brittle Zone

Abstract A deep ice core was drilled at Dome A, Antarctic Plateau, East Antarctica, which started with the installation of a casing in January 2012 and reached 800.8 m in January 2017. To date, a total of 337 successful ice-core drilling runs have been conducted, including 118 runs to drill the pilot hole. The total drilling time was 52 days, of which eight days were required for drilling down and reaming the pilot hole, and 44 days for deep ice coring. The average penetration depths of individual runs were 1 and 3.1 m for the pilot hole drilling and deep ice coring, respectively. The quality of the ice cores was imperfect in the brittle zone (650−800 m). Some of the troubles encountered are discussed for reference, such as armoured cable knotting, screws falling into the hole bottom, and damaged parts, among others.

Antifreeze thermal ice core drilling: an effective approach to the acquisition of ice cores

1998 ◽  
Vol 28 (3) ◽  
pp. 189-202 ◽  
Author(s):  
V Zagorodnov ◽  
L.G Thompson ◽  
J.J Kelley ◽  
B Koci ◽  
V Mikhalenko
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Core Drilling
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