scholarly journals Untersuchungen an Eisbohrkernen von Alpengletschern

1985 ◽  
Vol 40 (4) ◽  
pp. 223-229 ◽  
Author(s):  
B. Stauffer ◽  
U. Schotterer

Abstract. Cold alpine glaciers are archives of climatic Parameters. Core drilling in alpine glaciers allows to collect ice samples of ages up to 1000 years. First results from analyses of an ice core from Colle Gnifetti (Swiss Alps) show already interesting results. Frequent occurring dust bands contain mainly dust from the Sahara and are therefore characteristic for precipitations transported with subtropic air masses. An increase of the acidity of the precipitations starting at the beginning of our Century is most probably an anthropogenic effect. For the upper 10 m of the ice core, S04- and N03- concentrations have also been measured.

2014 ◽  
Vol 55 (68) ◽  
pp. 339-350 ◽  
Author(s):  
P.G. Talalay

AbstractMore than 170 years ago, Louis Agassiz, one of the creators of glacial theory, made his first attempt to drill into the bed of Unteraargletscher, Swiss Alps. Since that time, various systems for thermal and mechanical drilling have been designed especially for boring into ice, and some conventional drill rigs been adopted for ice coring. Although contemporary ice-drilling knowledge and techniques are now familiar, there remain many problems to be solved by advanced modern technology. Specific challenges related to improving old drilling methods and developing new emerging technologies include: (1) identification of depth limitation of ‘dry’ drilling; (2) improvement of casing; (3) searching for the new environmentally friendly low-temperature drilling fluids; (4) reliable elimination of sticking drills; (5) improvement of core quality in the brittle zone; (6) additional core sampling from borehole walls after the core has been drilled; (7) obtaining oriented core; (8) designing automation drilling systems; (9) developing rapid-access drills. Possible ways of solving these problems are presented below.


1988 ◽  
Vol 10 ◽  
pp. 183-187 ◽  
Author(s):  
D. Wagenbach ◽  
K.O. Münnich ◽  
U. Schotterer ◽  
H. Oeschger

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.


1988 ◽  
Vol 10 ◽  
pp. 183-187 ◽  
Author(s):  
D. Wagenbach ◽  
K.O. Münnich ◽  
U. Schotterer ◽  
H. Oeschger

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.


Geosciences ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 205
Author(s):  
Julius Kunz ◽  
Christof Kneisel

The internal structures of a moraine complex mostly provide information about the manner in which they develop and thus they can transmit details about several processes long after they have taken place. While the occurrence of glacier–permafrost interactions during the formation of large thrust moraine complexes at polar and subpolar glaciers as well as at marginal positions of former ice sheets has been well understood, their role in the formation of moraines on comparatively small alpine glaciers is still very poorly investigated. Therefore, the question arises as to whether evidence of former glacier–permafrost interactions can still be found in glacier forefields of small alpine glaciers and to what extent these differ from the processes in finer materials at larger polar or subpolar glaciers. To investigate this, electrical resistivity tomography (ERT) and ground-penetrating radar (GPR) surveys were carried out in the area of a presumed alpine thrust moraine complex in order to investigate internal moraine structures. The ERT data confirmed the presence of a massive ice core within the central and proximal parts of the moraine complex. Using GPR, linear internal structures were detected, which were interpreted as internal shear planes due to their extent and orientation. These shear planes lead to the assumption that the moraine complex is of glaciotectonic origin. Based on the detected internal structures and the high electrical resistivity values, it must also be assumed that the massive ice core is of sedimentary or polygenetic origin. The combined approach of the two methods enabled the authors of this study to detect different internal structures and to deduce a conceptual model of the thrust moraine formation.


1994 ◽  
Vol 20 ◽  
pp. 219-225 ◽  
Author(s):  
E.D. Waddington ◽  
D.L. Morse

10m firn temperatures are commonly used on the Antarctic plateau to estimate mean annual air temperatures. 10m firn temperatures measured at Taylor Dome (also referred to as McMurdo Dome in the literature), Antarctica, are influenced by a factor other than altitude and latitude that varies systematically across Taylor Dome. Some inter-related factors possibly contributing to the modern temperature variability are differences in sensible heat from warm or cold air masses, differences in wind strength and source region, differences in temperature inversion strength and differences in cloudiness. Our preliminary data are compatible with spatially variable katabatic winds that could control the winter temperature inversion strength to provide a large part of the signal. This has implications for paleoclimate studies.(1) Variations of the stable isotopes δ18O and δD from ice cores are a proxy for paleotemperature. The isotope thermometer is calibrated by comparing local isotope ratios with corresponding measured temperatures. In order to derive a useful isotope-temperature calibration, we must understand the processes that control the modern spatial variability of temperature. (2) In order to quantify past changes in local climate, we must understand processes that influence local spatial variability. If those processes differed in the past, ice-core climate reconstruction would be affected in two ways: through alteration of the geochemical record and through alteration of deep ice and firn temperatures.


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.


Author(s):  
Fernando Rodriguez-Morales ◽  
David Braaten ◽  
Hoang Trong Mai ◽  
John Paden ◽  
Prasad Gogineni ◽  
...  

2009 ◽  
Vol 55 (194) ◽  
pp. 985-996 ◽  
Author(s):  
M. Sigl ◽  
T.M. Jenk ◽  
T. Kellerhals ◽  
S. Szidat ◽  
H.W. Gäggeler ◽  
...  

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.


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