scholarly journals A new intermediate-depth ice-core drilling system

2014 ◽  
Vol 55 (68) ◽  
pp. 271-284 ◽  
Author(s):  
Simon G. Sheldon ◽  
Trevor J. Popp ◽  
Steffen B. Hansen ◽  
Thomas M. Hedegaard ◽  
Carsten Mortensen
Keyword(s):  
Future Development ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Surface ◽  
High Quality ◽  
International Partnerships ◽  
Intermediate Depth ◽  
Ice Cap ◽  
Drilling System ◽  
Set Up

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.

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 Glaciological Investigations of the Tropical Quelccaya Ice Cap, Peru

1980 ◽  
Vol 25 (91) ◽  
pp. 69-84 ◽  
Author(s):  
Lonnie G. Thompson
Keyword(s):  
Rainy Season ◽  
Ice Core ◽  
Ice Cores ◽  
Dry Season ◽  
Radioactive Material ◽  
Polar Regions ◽  
Near Surface ◽  
Ice Cap ◽  
Activity Measurements ◽  
Quelccaya Ice Cap

AbstractGlaciological results of the continuing investigations of the Quelccaya ice cap located at lat. 13° 56’ S., long. 70° 50’ W., in the Cordillera Oriental of southern Peru are presented. Ice cores to a depth of 15 m have been retrieved from the summit dome (5650 m), middle dome (5543 m), and south dome (5480 m) and sampled in detail for microparticle, oxygen-isotope, and total-β-activity measurements. Results of these core analyses indicate that although the summit of this ice cap is only 300 m above the annual snow line and the firn is temperate, an interpretable stratigraphic record is preserved. The marked seasonal ice stratigraphy is produced by the marked seasonal variation in regional precipitation. High concentrations of microparticles and β- radioactive material occur during the dry season (May-August). Microparticles deposited during the rainy season are larger than those deposited during the dry season. On the Quelccaya ice cap the most negative δ18O values occur during the warmer rainy season (the opposite occurs in polar regions). The near-surface mean δ value of – 21‰ is remarkably low for this tropical site where the measured mean annual air temperature is – 3°C The seasonality of the microparticles, total β activity, and isotope ratios offers the prospect of a climatic ice-core record from this tropical ice cap.

scholarly journals Apparent discrepancy of Tibetan ice core <i>δ</i><sup>18</sup>O records may be attributed to misinterpretation of chronology

2019 ◽  
Vol 13 (6) ◽  
pp. 1743-1752 ◽  
Author(s):  
Shugui Hou ◽  
Wangbin Zhang ◽  
Hongxi Pang ◽  
Shuang-Ye Wu ◽  
Theo M. Jenk ◽  
...  
Keyword(s):  
High Resolution ◽  
Ice Core ◽  
Ice Cores ◽  
Warming Trend ◽  
The Tibetan Plateau ◽  
Apparent Discrepancy ◽  
Ice Cap ◽  
Guliya Ice Core ◽  
Cooling Trend ◽  
Instrumental Period

Abstract. Ice cores from the Tibetan Plateau (TP) are widely used for reconstructing past climatic and environmental conditions that extend beyond the instrumental period. However, challenges in dating and interpreting ice core records often lead to inconsistent results. The Guliya ice core drilled from the northwestern TP suggested a cooling trend during the mid-Holocene based on its decreasing δ18O values, which is not observed in other Tibetan ice cores. Here we present a new high-resolution δ18O record of the Chongce ice cores drilled to bedrock ∼30 km away from the Guliya ice cap. Our record shows a warming trend during the mid-Holocene. Based on our results as well as previously published ice core data, we suggest that the apparent discrepancy between the Holocene δ18O records of the Guliya and the Chongce ice cores may be attributed to a possible misinterpretation of the Guliya ice core chronology.

scholarly journals Some comments on climatic reconstructions from ice cores drilled in areas of high melt

1997 ◽  
Vol 43 (143) ◽  
pp. 90-97 ◽  
Author(s):  
Roy M. Koerner
Keyword(s):  
Time Scales ◽  
Ice Core ◽  
Ice Cores ◽  
The Holocene ◽  
Ice Caps ◽  
Ice Cap ◽  
Thermal Maximum ◽  
Devon Ice Cap ◽  
Seasonal Signals ◽  
Cross Correlations

AbstractPoor consideration has been given in many Arctic circum-polar ice-core studies to the effect of summer snow melt on chemistry, stable-isotope concentrations and time-scales. Many of these corps are drilled close to the firn line where melt is intense. Some come from below the firn line where accumulation is solely in the form of super-imposed ice. In all cases, seasonal signals are reduced or removed and, in some, time gaps develop during periods of excessive melting which situate the drill site in the ablation zone. Consequently, cross correlations of assumed synchronous events among the cores are invalid, so that time-scales along the same cores differ between authors by factors of over 2. Many so-called climatic signals are imaginary rather than real. By reference to published analyses of cores from the superimposed ice zone on Devon Ice Cap (Koerner, 1970) and Meighen Ice Cap (Koerner and Paterson, 1974), it is shown how melt affects all the normally well-established ice-core proxies and leads to their misinterpretation. Despite these limitations, the cores can give valuable low-resolution records for all or part of the Holocene. They show that the thermal maximum in the circum-polar Arctic occurred in the early Holocene. This maximum, effected negative balances on all the ice caps and removed the smaller ones. Cooler conditions in the second half of the Holocene have caused the regrowth of these same ice caps.

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 Production drilling at WAIS Divide

2014 ◽  
Vol 55 (68) ◽  
pp. 147-155 ◽  
Author(s):  
Kristina R. Slawny ◽  
Jay A. Johnson ◽  
Nicolai B. Mortensen ◽  
Christopher J. Gibson ◽  
Joshua J. Goetz ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Sheet ◽  
Austral Summer ◽  
Snow Surface ◽  
Scientific Interest ◽  
High Quality ◽  
Core Drilling ◽  
Core Samples ◽  
Drill Fluid ◽  
Drilling Operations

AbstractThe 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 285m 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.

scholarly journals Characterizing the glaciological conditions at Halvfarryggen ice dome, Dronning Maud Land, Antarctica

2013 ◽  
Vol 59 (213) ◽  
pp. 9-20 ◽  
Author(s):  
Reinhard Drews ◽  
Carlos Martín ◽  
Daniel Steinhage ◽  
Olaf Eisen
Keyword(s):  
Flow Model ◽  
Ice Core ◽  
Ice Cores ◽  
Radar Data ◽  
Ice Thickness ◽  
Atmospheric Conditions ◽  
Ice Flow ◽  
International Partnerships ◽  
Drill Site ◽  
Dronning Maud Land

AbstractWe present a comprehensive approach (including field data, remote sensing and an anisotropic ice-flow model) to characterize Halvfarryggen ice dome in coastal Dronning Maud Land, Antarctica. This is a potential drill site for the International Partnerships in Ice Core Sciences, which has identified the need for ice cores covering atmospheric conditions during the last few millennia. We derive the surface topography, the ice stratigraphy from radar data, and accumulation rates which vary from 400 to 1670 kg m−2 a−1 due to preferred wind directions and changing surface slope. The stratigraphy shows anticlines and synclines beneath the divides. We transfer Dansgaard–Johnsen age–depth scales from the flanks along isochrones to the divide in the upper 20–50% of the ice thickness and show that they compare well with the results of a full-Stokes, anisotropic ice-flow model which predicts (1) 11 ka BP ice at 90% of the ice thickness, (2) a temporally stable divide for at least 2700–4500 years, (3) basal temperatures below the melting point (−12°C to −5°C) and (4) a highly developed crystal orientation fabric (COF). We suggest drilling into the apices of the deep anticlines, providing a good compromise between record length and temporal resolution and also facilitating studies of the interplay of anisotropic COF and ice flow.

scholarly journals Community change of microorganisms in the Muztagata and Dunde glacier and climatic and environmental implications

2016 ◽  
Author(s):  
Yong Chen ◽  
Xiang-Kai Li ◽  
Jing Si ◽  
Guang-Jian WU ◽  
Li-De Tian ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Cell Density ◽  
Ice Core ◽  
Ice Cores ◽  
Community Change ◽  
Rrna Gene ◽  
Environmental Implications ◽  
Depth Profiles ◽  
Ice Cap ◽  
Glacier Ice

Abstract. Microorganisms are continuously blown onto the glacier snow, and thus the glacial depth profiles provide excellent geographic archives of the microbial communities. However, it is uncertain about how the microbial communities respond to the climatic and environmental changes over the glacier ice. In the present study, the live microbial density, stable isotopic ratios, 18O/16O in the precipitation, and mineral particle concentrations along the glacial depth profiles were collected from ice cores from the Muztagata glacier and the Dunde ice cap. Six bacterial 16S rRNA gene clone libraries were established from the Dunde ice core. The Muztagata ice core presented seasonal response patterns for both live and total cell density with high cell density occurring in the warming spring and summer. Both ice core data showed a frequent association of dust and microorganisms in the ice. Genera Polaromas sp., Pedobacter sp, Flavobacterium sp., Cryobacteriium sp., and Propionibacterium/Blastococcus sp. frequently appeared at the six tested ice layers, and constituted the dominant species endemic to the Dunde ice cap, whereas some genera such as Rhodoferax sp., Variovorax sp., Sphingobacterium sp., Cyanobacterium sp., Knoellia sp., and Luteolibacter sp. rarely presented in the ice. In conclusion, data present a discrete increase of microbial cell density in the warming seasons and biogeography of the microbial communities associated with the predominance of a few endemic groups in the local glacial regions. This reinforces our hypothesis of dust-borne and post-deposition being the main agents interactively controlling microbial load in the glacier ice.

scholarly journals Glacier ice archives fifteen-thousand-year-old viruses

2020 ◽  
Author(s):  
Zhi-Ping Zhong ◽  
Natalie E. Solonenko ◽  
Yueh-Fen Li ◽  
Maria C. Gazitúa ◽  
Simon Roux ◽  
...  
Keyword(s):  
In Silico ◽  
Ice Core ◽  
Ice Cores ◽  
Metagenomic Sequencing ◽  
Climate Conditions ◽  
Ice Cap ◽  
Glacier Ice ◽  
Viral Communities ◽  
Microbial Groups ◽  
Sampling Procedures

AbstractWhile glacier ice cores provide climate information over tens to hundreds of thousands of years, study of microbes is challenged by ultra-low-biomass conditions, and virtually nothing is known about co-occurring viruses. Here we establish ultra-clean microbial and viral sampling procedures and apply them to two ice cores from the Guliya ice cap (northwestern Tibetan Plateau, China) to study these archived communities. This method reduced intentionally contaminating bacterial, viral, and free DNA to background levels in artificial-ice-core control experiments, and was then applied to two authentic ice cores to profile their microbes and viruses. The microbes differed significantly across the two ice cores, presumably representing the very different climate conditions at the time of deposition that is similar to findings in other cores. Separately, viral particle enrichment and ultra-low-input quantitative viral metagenomic sequencing from ∼520 and ∼15,000 years old ice revealed 33 viral populations (i.e., species-level designations) that represented four known genera and likely 28 novel viral genera (assessed by gene-sharing networks). In silico host predictions linked 18 of the 33 viral populations to co-occurring abundant bacteria, including Methylobacterium, Sphingomonas, and Janthinobacterium, indicating that viruses infected several abundant microbial groups. Depth-specific viral communities were observed, presumably reflecting differences in the environmental conditions among the ice samples at the time of deposition. Together, these experiments establish a clean procedure for studying microbial and viral communities in low-biomass glacier ice and provide baseline information for glacier viruses, some of which appear to be associated with the dominant microbes in these ecosystems.ImportanceThis study establishes ultra-clean microbial and viral sampling procedures for glacier ice, which complements prior in silico decontamination methods and expands, for the first time, the clean procedures to viruses. Application of these methods to glacier ice confirmed prior common microbiological findings for a new ice core climate record, and provides a first window into viral genomes and their ecology from glacier ice across two time horizons, and emphasizes their likely impact on abundant microbial groups. Together these efforts provide clean sampling approaches and foundational datasets that should enable simultaneous access to an archived virosphere in glacier ice.

scholarly journals Soluble Impurities In Ice Core D-1 Of Dunde Ice Cap, China, Over The Last 500 Years

1990 ◽  
Vol 14 ◽  
pp. 363
Author(s):  
Wu Xiaoling ◽  
Liu Jingsona ◽  
Yang Qinzhou
Keyword(s):  
Atmospheric Chemistry ◽  
Industrial Revolution ◽  
Environmental Changes ◽  
Ice Core ◽  
Ice Cores ◽  
Short Term ◽  
The Core ◽  
Ice Cap ◽  
National Foundation ◽  
Analysis Of Time Series

This paper gives the preliminary results of 26 trace element measurements of ice cores from Dunde Ice Cap, China. The chemical composition of soluble impurities along ice core D-1 covering the last 500 years B P., is reported and interpreted in terms of atmospheric contributions. The dust content in ice cores of Dunde Ice Cap is 36 times higher than in Byrd Station, Antarctica. Variations of soluble elements such as Ca, Mg, Κ and Na, in Dunde Ice cores are very sensitive to climatic and environmental changes. The 25 trace elements in ice core D-1 (K, Na, Ca, Mg, Cd, Cr, Co, Cu, Fe, Mn, Mo, Ni, Pb, Al, Sr, Ti, V, Zn, As, Ba, Β, Li, Ρ, S, Sn) were measured. Cationicions arranged in order of content are as follows: Ca &gt; Na &gt; Mg &gt; Κ &gt; Αl &gt; Fe &gt; Ζn &gt; Cu &gt; Μn &gt; Pb &gt; Cr &gt; Ni &gt; Co &gt; Cd etc. The content of soluble impurities has typical terrestrial features. Rock-forming elements such as Ca, Mg, Κ, Na, Si, Al, and Fe make up 99% in the core samples. Particular attention is given to the possible impact of the so-called “pre-Industrial Revolution period” and man’s influence on the atmospheric chemistry. The spectral analysis of time series for the variation of each of the 26 contributions show a 92 year cycle that is present in the variation of all 26 ions with depth. Short-term variations, such as 23, 31, 48, 81 year cycles, are also discussed. The ice-core research program has been supported by the Chinese National Foundation of Natural Science under Grant DO125-4860011.

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