scholarly journals Portable system for intermediate-depth ice-core drilling

2000 ◽  
Vol 46 (152) ◽  
pp. 167-172 ◽  
Author(s):  
V. Zagorodnov ◽  
L. G. Thompson ◽  
E. Mosley-Thompson

AbstractA lightweight, portable drilling system for coring up to 500 m depths has been developed and field-tested. The drilling system includes four major components: (1) an electromechanical (EM) dry-hole drill; (2) an ethanol thermal electric drill; (3) a drill set-up with a 500 m cable capacity; and (4) a controller unit. The system may be switched quickly from a dry-hole EM drill to an antifreeze thermal electric drill. This lightweight system makes ice-core drilling more cost-efficient, and creates a minimal environmental impact. The new EM drill, which recovers 100 mm diameter, 1 m long pieces of ice core, is 3.2 m long and weighs 35 kg. This drill and the drilling set-up were recently tested at the Raven (former Dye 2) site, southern Greenland, where a core was recovered to 122 m. The thermal drill is 2.9 m long and weighs 25 kg. It produces 100 mm diameter, 2.1 m long pieces of ice core, and was tested to 315 m in Franz Josef Land, Eurasian Arctic. The drilling set-up with a 250 m cable weighs about 100 kg (or 128 kg for 500 m of cable). After minor adjustments this drill system retrieved cores of better quality than those recovered by other drill systems under similar glaciological conditions. After adjustments to optimize its performance, the drill retrieved 5.25 m of core per hour over the depth range 0–21 m.

2019 ◽  
Vol 65 (249) ◽  
pp. 149-156 ◽  
Author(s):  
ZHENGYI HU ◽  
PAVEL TALALAY ◽  
ZHICHUAN ZHENG ◽  
PINLU CAO ◽  
GUITAO SHI ◽  
...  

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.


2005 ◽  
Vol 51 (174) ◽  
pp. 491-501 ◽  
Author(s):  
V. Zagorodnov ◽  
L.G. Thompson ◽  
P. Ginot ◽  
V. Mikhalenko

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.


2020 ◽  
pp. 1-11
Author(s):  
Hideaki Motoyama ◽  
Akiyoshi Takahashi ◽  
Yoichi Tanaka ◽  
Kunio Shinbori ◽  
Morihiro Miyahara ◽  
...  

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.


2014 ◽  
Vol 55 (68) ◽  
pp. 271-284 ◽  
Author(s):  
Simon G. Sheldon ◽  
Trevor J. Popp ◽  
Steffen B. Hansen ◽  
Thomas M. Hedegaard ◽  
Carsten Mortensen

AbstractSeveral recent projects associated with the IPICS (International Partnerships in Ice Core Sciences) 2k array have demanded the recovery of ice core to depths in excess of several hundred metres (e.g. Flade Isblink, Greenland (2006), Aurora Basin, Antarctica (2008/09), NEEM, Greenland (2011), Aurora Basin North (2013/14) and Renland ice cap, Greenland (2015)). These projects require that the overall system weight is low, that the ability to set up and operate are within the limitations of a small-camp environment and that the overall logistical and transportation costs are kept to a minimum. Using these criteria, a new drilling system capable of drilling >400m depth was seen as a useful future development. Here we report on a new intermediate-depth drilling system designed to recover high-quality 98 mm diameter ice cores from close to surface down to depths of 1000 m by two or more operators in a small deep-field camp environment. The total weight of the system on the snow surface is ∼490 kg, of which the intermediate-depth winch is the single heaviest component at 305 kg with 1000 m of cable.


Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1208
Author(s):  
Aina Año-Perello ◽  
Zurisaday Santos-Jimenez ◽  
Teresa Encinas ◽  
Paula Martinez-Ros ◽  
Antonio Gonzalez-Bulnes

The present study aimed to set up a short-term protocol for synchronization of follicular wave emergence in sheep, concomitant with estrus synchronization, which would improve ovarian response in assisted reproductive technologies. Administration of a single GnRH dose, concomitant with the insertion of a progesterone-loaded CIDR device, caused regression of gonadotrophin-dependent follicles ≥4 mm in all the GnRH-treated sheep and in around 80% of the controls treated only with CIDR (p < 0.05). Similar percentages of ewes lost all follicles (around 70%) or only the largest one (around 30%) in both groups. Hence, 54.1% and 70% of the sheep lost all large follicles and initiated a new follicular wave in the control and GnRH groups, respectively (p < 0.05). The remaining sheep showed follicles that were still not dependent of luteinizing hormone (LH). So, in fact, all the sheep had non-dominant follicles after treatment. In conclusion, a treatment including GnRH at CIDR insertion would offer a time- and cost-efficient protocol for inducing follicular turnover and synchronizing a new follicular wave at any stage of the estrous cycle.


1999 ◽  
Vol 45 (149) ◽  
pp. 22-30 ◽  
Author(s):  
F. Pauer ◽  
S. Kipfstuhl ◽  
W. F. Kuhs ◽  
H. Shoji

AbstractWe performed microscopic observations and a statistical study of the number, size and shape distribution of clathrates in the GRIP (Greenland Ice Core Project) deep ice core, using 185 samples from a depth range of 1016–3014 m, spanning a period of 6 to >110 ka BP and encompassing the Holocene, Wisconsin and Eemian periods. The number concentration of the clathrates varied considerably with climatic changes. It was possible to detect the rapid climatic oscillations in the last glacial between 13 and 110 ka BP, the Dansgaard–Oeschger cycles, in the number-concentration profile of clathrates. The mean volume of clathrates is less clearly influenced by climatic factors, with a tendency towards greater volumes in warmer periods, but also a growth of clathrates with depth could be detected. This growth rate was calculated to be 3.1 × 10-12 cm3 a-1. The amount of gases captured in the clathrates is estimated to be significantly smaller than the total amount of air determined by gas-concentration measurements. This points to diffusion processes of atmospheric gases within the ice matrix.


2014 ◽  
Vol 55 (68) ◽  
pp. 243-252 ◽  
Author(s):  
Jack Triest ◽  
Robert Mulvaney ◽  
Olivier Alemany

AbstractThe British Antarctic Survey, in collaboration with Laboratoire de Glaciologie et Géophysique de l’Environnement, has in recent years successfully drilled to bedrock on three remote sites around the Antarctic Peninsula. Based on the experience from the multi-season project at Berkner Island (948m depth, 2002–05) we optimized the drill set-up to better suit two subsequent single-season projects at James Ross Island (363m depth, 2008) and Fletcher Promontory (654m depth, 2012). The adaptations, as well as the reasons for them, are discussed in detail and include a drill tent set-up without a trench; drilling without a borehole casing with a relatively low fluid column height; and using a shorter drill. These optimizations were aimed at reducing cargo loads and installation time while maintaining good core quality, productivity and a safe working environment. In addition, we introduce a number of innovations, ranging from a new lightweight cable tensioning device and drill-head design to core storage and protection trays. To minimize the environmental impact, all the drill fluid was successfully recovered at both sites and we describe and evaluate this operation.


2000 ◽  
Vol 46 (153) ◽  
pp. 341-345 ◽  
Author(s):  
H. Engelhardt ◽  
B. Kamb ◽  
R. Bolsey

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.


2007 ◽  
Vol 47 ◽  
pp. 115-124 ◽  
Author(s):  
Robert Mulvaney ◽  
Olivier Alemany ◽  
Philippe Possenti

AbstractWe describe a project to retrieve a 948m deep ice core from Berkner Island, Antarctica. Using relatively lightweight logistics and a small team, the drilling operation over three austral summer seasons used electromechanical drilling technology, described in detail, from a covered shallow pit and a fluid-filled borehole. A basal temperature well below pressure-melting point meant that no drilling problems were encountered when approaching the bed and the borehole penetrated through to the base of the ice sheet, and sediment was retrieved from beneath the ice.


1998 ◽  
Vol 44 (146) ◽  
pp. 179-181 ◽  
Author(s):  
J. M. Casas ◽  
F. Sàbat ◽  
J. M. Vilaplana ◽  
J. M. Parés ◽  
D. M. Pomeroy

Abstract A new portable device for ice-core drilling, specially designed for thin tephra-layer sampling, was tested on the South Shetland glaciers during the 1994-95 Antarctic summer. The machine is based on a combination of the standard paleomagnetism drilling machine and a specially built drill-bit designed for ice-coring.


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