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 Towards radiocarbon dating of ice cores

2009 ◽  
Vol 55 (194) ◽  
pp. 985-996 ◽  
Author(s):  
M. Sigl ◽  
T.M. Jenk ◽  
T. Kellerhals ◽  
S. Szidat ◽  
H.W. Gäggeler ◽  
...  
Keyword(s):  
Aerosol Particles ◽  
Ice Core ◽  
Ice Cores ◽  
Swiss Alps ◽  
Carbonaceous Aerosol ◽  
Polar Ice ◽  
Low Latitude ◽  
Bolivian Andes ◽  
Glacier Ice ◽  
Dating Method

AbstractA recently developed dating method for glacier ice, based on the analysis of radiocarbon in carbonaceous aerosol particles, is thoroughly investigated. We discuss the potential of this method to achieve a reliable dating using examples from a mid- and a low-latitude ice core. Two series of samples from Colle Gnifetti (4450 m a.s.l., Swiss Alps) and Nevado Illimani (6300 m a.s.l., Bolivian Andes) demonstrate that the 14C ages deduced from the water-insoluble organic carbon fraction represent the age of the ice. Sample sizes ranged between 7 and 100 μg carbon. For validation we compare our results with those from independent dating. This new method is thought to have major implications for dating non-polar ice cores in the future, as it provides complementary age information for time periods not accessible with common dating techniques.

The Anthropogenic Impact on Snow Chemistry at Colle Gnifetti, Swiss Alps

1988 ◽  
Vol 10 ◽  
pp. 183-187 ◽  
Author(s):  
D. Wagenbach ◽  
K.O. Münnich ◽  
U. Schotterer ◽  
H. Oeschger
Keyword(s):  
Chemical Analysis ◽  
Ice Core ◽  
Ice Cores ◽  
Summer Precipitation ◽  
Snow Accumulation ◽  
Swiss Alps ◽  
Saharan Dust ◽  
Water Conductivity ◽  
Air Masses ◽  
Melt Water

By chemical analysis of the upper 40 m of a 124 m ice core from a high-altitude Alpine glacier (Colle Gnifetti, Swiss Alps; 4450 m a.s.l.), records of mineral dust, pH, melt-water conductivity, nitrate and sulfate are obtained. The characteristics of the drilling site are discussed, as derived from glacio-meteorological and chemical analysis. As a consequence of high snow-erosion rates (usually during the winter months), annual snow accumulation is dominated by summer precipitation. Clean-air conditions prevail even during summer; however, they are frequently interrupted by polluted air masses or by air masses which are heavily loaded with desert dust.Absolutely dated reference horizons for Saharan dust, together with the position of the broad nuclear-weapon tritium peak, provide the time-scale for the following statements:(1) Since at least the turn of the century the background melt-water conductivity has been rising steadily, as has the mean snow acidity. The trend of increasing background conductivity at Colle Gnifetti (1.9μS/cm around the beginning of this century, and at present 3.4 μS/cm) is found to be comparable with the records of mean melt-water conductivity reported from ice cores from the Canadian High Arctic.(2) Sulfate and nitrate concentrations are higher by a factor of 4–5 than they were at the beginning of the century. This is to be compared with the two- to three-fold rise in the concentrations in south Greenland during about the same time span.

scholarly journals The Anthropogenic Impact on Snow Chemistry at Colle Gnifetti, Swiss Alps

1988 ◽  
Vol 10 ◽  
pp. 183-187 ◽  
Author(s):  
D. Wagenbach ◽  
K.O. Münnich ◽  
U. Schotterer ◽  
H. Oeschger
Keyword(s):  
Chemical Analysis ◽  
Ice Core ◽  
Ice Cores ◽  
Summer Precipitation ◽  
Snow Accumulation ◽  
Swiss Alps ◽  
Saharan Dust ◽  
Water Conductivity ◽  
Air Masses ◽  
Melt Water

By chemical analysis of the upper 40 m of a 124 m ice core from a high-altitude Alpine glacier (Colle Gnifetti, Swiss Alps; 4450 m a.s.l.), records of mineral dust, pH, melt-water conductivity, nitrate and sulfate are obtained. The characteristics of the drilling site are discussed, as derived from glacio-meteorological and chemical analysis. As a consequence of high snow-erosion rates (usually during the winter months), annual snow accumulation is dominated by summer precipitation. Clean-air conditions prevail even during summer; however, they are frequently interrupted by polluted air masses or by air masses which are heavily loaded with desert dust. Absolutely dated reference horizons for Saharan dust, together with the position of the broad nuclear-weapon tritium peak, provide the time-scale for the following statements: (1) Since at least the turn of the century the background melt-water conductivity has been rising steadily, as has the mean snow acidity. The trend of increasing background conductivity at Colle Gnifetti (1.9μS/cm around the beginning of this century, and at present 3.4 μS/cm) is found to be comparable with the records of mean melt-water conductivity reported from ice cores from the Canadian High Arctic. (2) Sulfate and nitrate concentrations are higher by a factor of 4–5 than they were at the beginning of the century. This is to be compared with the two- to three-fold rise in the concentrations in south Greenland during about the same time span.

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 NALPS19: Sub-orbital scale climate variability recorded in Northern Alpine speleothems during the last glacial period

2019 ◽  
Author(s):  
Gina E. Moseley ◽  
Christoph Spötl ◽  
Susanne Brandstätter ◽  
Tobias Erhardt ◽  
Marc Luetscher ◽  
...  
Keyword(s):  
Climate Variability ◽  
Asian Monsoon ◽  
Ice Core ◽  
Ice Cores ◽  
High Elevation ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Change State ◽  
The Last Glacial

Abstract. Sub-orbital-scale climate variability of the last glacial period provides important insights into the rates that the climate can change state, the mechanisms that drive that change, and the leads, lags and synchronicity occurring across different climate zones. Such short-term climate variability has previously been investigated using speleothems from the northern rim of the Alps (NALPS), enabling direct chronological comparisons with highly similar shifts in Greenland ice cores. In this study, we present NALPS19, which includes a revision of the last glacial NALPS δ18O chronology over the interval 118.3 to 63.7 ka using eleven,newly-available, clean, precisely-dated stalagmites from five caves. Using only the most reliable and precisely dated records, this period is now 90 % complete and is comprised of 15 stalagmites from seven caves. Where speleothems grew synchronously, major transitional events between stadials and interstadials (and vice versa) are all in agreement within uncertainty. Ramp-fitting analysis further reveals good agreement between the NALPS19 speleothem δ18O record, the GICC05modelext NGRIP ice-core δ18O record, and the Asian Monsoon composite speleothem δ18O record. In contrast, NGRIP ice-core δ18O on AICC2012 appears to be considerably too young. We also propose a longer duration for the interval covering Greenland Stadial (GS) 22 to GS-21.2 in line with the Asian monsoon and NGRIP-EDML. Given the near-complete record of δ18O variability during the last glacial period in the northern Alps, we offer preliminary considerations regarding the controls on mean δ18O. We find that as expected, δ18O values became increasingly more depleted with distance from the oceanic source regions, and increasingly depleted with increasing altitude. Exceptions were found for some high-elevation sites that locally display δ18O values that are too high in comparison to lower-elevation sites, thus indicating a summer bias in the recorded signal. Finally, we propose a new mechanism for the centennial-scale stadial-level depletions in δ18O such as "pre-cursor" events GS-16.2, GS-17.2, GS-21.2, and GS-23.2, as well as the "within-interstadial" GS-24.2 event. Our new high-precision chronology shows that each of these δ18O depletions occurred shortly following rapid rises in sea level associated with increased ice-rafted debris and southward shifts in the Intertropical Convergence Zone, suggesting that influxes of meltwater from moderately-sized ice sheets may have been responsible for the cold reversals causing the AMOC to slow down similar to the Preboreal Oscillation and Older Dryas deglacial events.

scholarly journals Tracing devastating fires in Portugal to a snow archive in the Swiss Alps: a case study

2020 ◽  
Author(s):  
Dimitri Osmont ◽  
Sandra Brugger ◽  
Anina Gilgen ◽  
Helga Weber ◽  
Michael Sigl ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Swiss Alps ◽  
Natural Phenomenon ◽  
Burned Area ◽  
Research Station ◽  
Test Bed ◽  
Fire Event ◽  
Carbonaceous Particles ◽  
Microscopic Charcoal

Abstract. Recent large wildfires, such as those in Portugal in 2017, have devastating impacts on societies, economy, ecosystems and environments. However, wildfires are a natural phenomenon, which has been exacerbated by land use during the past millennia. Ice cores are one of the archives preserving information on fire occurrences over these timescales. A difficulty is that emission sensitivity of ice cores is often unknown, which constitutes a source of uncertainty in the interpretation of such archives. Information from specific and well-documented case studies is therefore useful to better understand the spatial representation of ice-core burning records. The wildfires near Pedrógão Grande in Central Portugal in 2017 provided a test bed to link a fire event to its footprint left in a high-alpine snowpack considered a surrogate for high-alpine ice-core sites. Here, we (1) analyzed black carbon (BC) and microscopic charcoal particles deposited in the snowpack close to the high-alpine research station Jungfraujoch in the Swiss Alps, (2) calculated backward trajectories based on ERA-Interim reanalysis data and simulated the transport of these carbonaceous particles using a global aerosol-climate model, and (3) analyzed the fire spread, its spatial and temporal extent, as well as its intensity, with remote sensing (e.g. MODIS) active fire and burned area products. A peak of atmospheric equivalent BC (eBC) observed at the Jungfraujoch research station on 22nd June, with elevated eBC levels until the 25th June, is in correspondence with a peak in refractory BC (rBC) and microscopic charcoal observed in the snow layer. rBC was mainly scavenged by wet deposition and we obtained scavenging ratios ranging from 81 to 91. Unlike for microscopic charcoal, the model did not well reproduce the observed rBC signal. Our study reveals that microscopic charcoal can be transported over long distances (1500 km), and that snow and ice archives are much more sensitive to distant events than sedimentary archives, for which the signal is dominated by local fires. Microscopic charcoal concentrations were exceptionally high since this single outstanding event deposited as many charcoal particles per day as during an average year in ice cores. This study unambiguously links the fire tracers in the snow with the highly intensive fires in Portugal, where a total burned area of 501 km2 was observed on the basis of satellite fire products. According to our simulations, this fire event emitted at least 203.5 tons of BC.

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 Age ranges of the Tibetan ice cores with emphasis on the Chongce ice cores, western Kunlun Mountains

2018 ◽  
Vol 12 (7) ◽  
pp. 2341-2348 ◽  
Author(s):  
Shugui Hou ◽  
Theo M. Jenk ◽  
Wangbin Zhang ◽  
Chaomin Wang ◽  
Shuangye Wu ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
High Elevation ◽  
The Other ◽  
Ice Cap ◽  
The North ◽  
Kunlun Mountains ◽  
Guliya Ice Core ◽  
Western Kunlun ◽  
Drilling Site

Abstract. An accurate chronology is the essential first step for a sound understanding of ice core records. However, dating ice cores drilled from the high-elevation glaciers is challenging and often problematic, leading to great uncertainties. The Guliya ice core, drilled to the bedrock (308.6 m in length) along the western Kunlun Mountains on the north-western Tibetan Plateau (TP) and widely used as a benchmark for palaeoclimate research, is believed to reach >500 ka (thousand years) at its bottom. Meanwhile other Tibetan ice cores (i.e. Dasuopu and East Rongbuk in the Himalayas, Puruogangri in the central TP and Dunde in the north-eastern TP) are mostly of Holocene origin. In this study, we drilled four ice cores into bedrock (216.6, 208.6, 135.8 and 133.8 m in length, respectively) from the Chongce ice cap ∼30 km to the Guliya ice core drilling site. We took measurements of 14C, 210Pb, tritium and β activity for the ice cores, and used these values in a two-parameter flow model to establish the ice core depth–age relationship. We suggested that the Chongce ice cores might be of Holocene origin, consistent with the other Tibetan ice cores except Guliya. The remarkable discrepancy between the Guliya and all the other Tibetan ice core chronology implies that more effort is necessary to explore multiple dating techniques to confirm the age ranges of the TP glaciers, including those from Chongce and Guliya.

scholarly journals A potential high-elevation ice-core site at Hielo Patagόnico Sur

2006 ◽  
Vol 43 ◽  
pp. 8-13 ◽  
Author(s):  
Margit Schwikowski ◽  
Sabina Brütsch ◽  
Gino Casassa ◽  
Andrés Rivera
Keyword(s):  
Wind Erosion ◽  
Ice Core ◽  
Ice Cores ◽  
High Elevation ◽  
The Core ◽  
Clear Sign ◽  
Southern Patagonia ◽  
Core Site ◽  
Ice Core Record ◽  
Good Potential

AbstractThe Patagonia icefields constitute a unique location in the Southern Hemisphere for obtaining non-polar paleo-records from ice cores south of 45°S. Nevertheless, no ice-core record with meaningful paleoclimate information has yet been obtained from Patagonia. This deficiency is due to extremely harsh field conditions, and to the fact that the main plateaus of both Hielo Patagónico Norte (HPN; northern Patagonia icefield) and Hielo Patagónico Sur (HPS; southern Patagonia icefield) are strongly affected by meltwater percolation. In order to explore the suitability of high-elevation glacier sites at HPS as paleoclimate archives, three shallow firn cores were retrieved covering the altitude range 1543−2300 ma.s.l. The glaciochemical records from the two lower sites confirm the presence of superimposed ice, a clear sign of meltwater formation and percolation. In the core from 2300 m, the glaciochemical signature appears to be preserved, indicating that no significant melting occurred. Although there might be problems associated with wind erosion and extreme melt events, there is good potential for well-preserved paleo-records within glaciers in the Patagonia icefields located higher than 2300 m.

scholarly journals Extraction of Dissolved Organic Carbon from Glacier Ice for Radiocarbon Analysis

Radiocarbon ◽  
2019 ◽  
Vol 61 (03) ◽  
pp. 681-694 ◽  
Author(s):  
L Fang ◽  
J Schindler ◽  
T M Jenk ◽  
C Uglietti ◽  
S Szidat ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Working Conditions ◽  
Irradiation Time ◽  
Ice Core ◽  
Ice Cores ◽  
Swiss Alps ◽  
Carbonaceous Aerosols ◽  
Core Samples ◽  
Reported Data

ABSTRACTAlpine glaciers are valuable archives for the reconstruction of human impact on the environment. Besides dating purposes, measurement of radiocarbon (14C) content provides a powerful tool for long-term source apportionment studies on the carbonaceous aerosols incorporated in ice cores. In this work, we present an extraction system for 14C analyses of dissolved organic carbon (DOC) in ice cores. The setup can process ice samples of up to 350 g mass and offers ultra-clean working conditions for all extraction steps. A photo-oxidation method is applied by means of external UV irradiation of the sample. For an irradiation time of 30 min with catalyzation by addition of Fe2+ and H2O2, we achieve an efficiency of 96 ± 6% on average. Inert gas working conditions and stringent decontamination procedures enable a low overall blank of 1.9 ± 1.6 μg C with a F14C value of 0.68 ± 0.13. This makes it possible to analyze the DOC in ice samples with a carbon content of as low as 25 μg C kg−1 ice. For a first validation, the new method was applied to ice core samples from the Swiss Alps. The average DOC concentration and F14C values for the Fiescherhorn ice core samples show good agreement with previously reported data for the investigated period of 1925–1936 AD.

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