Articles | Volume 15, issue 2
https://doi.org/10.5194/tc-15-677-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-15-677-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
12 Feb 2021
Research article |
| 12 Feb 2021
| 12 Feb 2021
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps
Sebastian Hellmann
CORRESPONDING AUTHOR
Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland
Institute of Geophysics, ETH Zurich, Zurich, Switzerland
Johanna Kerch
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
now at: GZG Computational Geoscience, Georg August University of Göttingen, Göttingen, Germany
Ilka Weikusat
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Department of Geosciences, Eberhard Karls University of Tübingen, Tübingen, Germany
Andreas Bauder
Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland
Melchior Grab
Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland
Institute of Geophysics, ETH Zurich, Zurich, Switzerland
Guillaume Jouvet
Department of Geography, University of Zurich, Zurich, Switzerland
Autonomous Systems Laboratory, ETH Zurich, Zurich, Switzerland
Margit Schwikowski
Paul Scherrer Institute, Villingen, Switzerland
Hansruedi Maurer
Institute of Geophysics, ETH Zurich, Zurich, Switzerland
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Eef C. H. van Dongen, Guillaume Jouvet, Shin Sugiyama, Evgeny A. Podolskiy, Martin Funk, Douglas I. Benn, Fabian Lindner, Andreas Bauder, Julien Seguinot, Silvan Leinss, and Fabian Walter
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Guillaume Jouvet, Stefan Röllin, Hans Sahli, José Corcho, Lars Gnägi, Loris Compagno, Dominik Sidler, Margit Schwikowski, Andreas Bauder, and Martin Funk
The Cryosphere, 14, 4233–4251, https://doi.org/10.5194/tc-14-4233-2020, https://doi.org/10.5194/tc-14-4233-2020, 2020
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Dimitri Osmont, Sandra Brugger, Anina Gilgen, Helga Weber, Michael Sigl, Robin L. Modini, Christoph Schwörer, Willy Tinner, Stefan Wunderle, and Margit Schwikowski
The Cryosphere, 14, 3731–3745, https://doi.org/10.5194/tc-14-3731-2020, https://doi.org/10.5194/tc-14-3731-2020, 2020
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In this field study, we repeated ground-penetrating radar measurements over an active englacial channel network that transports meltwater through the glacier. We successfully imaged the englacial meltwater pathway and were able to delimitate the channel's shape. Meltwater from the glacier can impact the glacier's dynamics if it reaches the ice–bed interface, and therefore monitoring these englacial drainage networks is important to understand how these networks behave throughout a season.
Joseph Doetsch, Hannes Krietsch, Cedric Schmelzbach, Mohammadreza Jalali, Valentin Gischig, Linus Villiger, Florian Amann, and Hansruedi Maurer
Solid Earth, 11, 1441–1455, https://doi.org/10.5194/se-11-1441-2020, https://doi.org/10.5194/se-11-1441-2020, 2020
Ernst-Jan N. Kuiper, Ilka Weikusat, Johannes H. P. de Bresser, Daniela Jansen, Gill M. Pennock, and Martyn R. Drury
The Cryosphere, 14, 2429–2448, https://doi.org/10.5194/tc-14-2429-2020, https://doi.org/10.5194/tc-14-2429-2020, 2020
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A composite flow law model applied to crystal size distributions from the NEEM deep ice core predicts that fine-grained layers in ice from the last Glacial period localize deformation as internal shear zones in the Greenland ice sheet deforming by grain-size-sensitive creep. This prediction is consistent with microstructures in Glacial age ice.
Ernst-Jan N. Kuiper, Johannes H. P. de Bresser, Martyn R. Drury, Jan Eichler, Gill M. Pennock, and Ilka Weikusat
The Cryosphere, 14, 2449–2467, https://doi.org/10.5194/tc-14-2449-2020, https://doi.org/10.5194/tc-14-2449-2020, 2020
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Fast ice flow occurs in deeper parts of polar ice sheets, driven by high stress and high temperatures. Above 262 K ice flow is further enhanced, probably by the formation of thin melt layers between ice crystals. A model applying an experimentally derived composite flow law, using temperature and grain size values from the deepest 540 m of the NEEM ice core, predicts that flow in fine-grained layers is enhanced by a factor of 10 compared to coarse-grained layers in the Greenland ice sheet.
Guillaume Jouvet, Eef van Dongen, Martin P. Lüthi, and Andreas Vieli
Geosci. Instrum. Method. Data Syst., 9, 1–10, https://doi.org/10.5194/gi-9-1-2020, https://doi.org/10.5194/gi-9-1-2020, 2020
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We report the first-ever in situ measurements of ice flow motion using a remotely controlled drone. We used a quadcopter to land on a highly crevassed area of Eqip Sermia Glacier, Greenland. The drone measured 70 cm of ice displacement over more than 4 h thanks to an accurate onboard GPS. Our study demonstrates that drones have great potential for geoscientists, especially to deploy sensors in hostile environments such as glaciers.
Lisbeth Langhammer, Melchior Grab, Andreas Bauder, and Hansruedi Maurer
The Cryosphere, 13, 2189–2202, https://doi.org/10.5194/tc-13-2189-2019, https://doi.org/10.5194/tc-13-2189-2019, 2019
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We have developed a novel procedure for glacier thickness estimations that combines traditional glaciological modeling constraints with ground-truth data, for example, those obtained with ground-penetrating radar (GPR) measurements. This procedure is very useful for determining ice volume when only limited data are available. Furthermore, we outline a strategy for acquiring GPR data on glaciers, such that the cost/benefit ratio is optimized.
Shugui Hou, Wangbin Zhang, Hongxi Pang, Shuang-Ye Wu, Theo M. Jenk, Margit Schwikowski, and Yetang Wang
The Cryosphere, 13, 1743–1752, https://doi.org/10.5194/tc-13-1743-2019, https://doi.org/10.5194/tc-13-1743-2019, 2019
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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.
Dimitri Osmont, Michael Sigl, Anja Eichler, Theo M. Jenk, and Margit Schwikowski
Clim. Past, 15, 579–592, https://doi.org/10.5194/cp-15-579-2019, https://doi.org/10.5194/cp-15-579-2019, 2019
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We present the first black carbon (BC) ice-core record from the Andes (Illimani, Bolivia). It spans the entire Holocene and reflects biomass burning emissions from the Amazon Basin, with high (low) concentrations during warm–dry (wet–cold) periods. The highest fire activity occurred during the Holocene Climatic Optimum (7000–3000 BCE). Recent BC levels, increasing since 1730 CE, do not exceed those of the Medieval Warm Period. The contribution from industrial and traffic emissions remains minor.
Michael Sigl, Nerilie J. Abram, Jacopo Gabrieli, Theo M. Jenk, Dimitri Osmont, and Margit Schwikowski
The Cryosphere, 12, 3311–3331, https://doi.org/10.5194/tc-12-3311-2018, https://doi.org/10.5194/tc-12-3311-2018, 2018
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The fast retreat of Alpine glaciers since the mid-19th century documented in photographs is used as a symbol for the human impact on global climate, yet the key driving forces remain elusive. Here we argue that not industrial soot but volcanic eruptions were responsible for an apparently accelerated deglaciation starting in the 1850s. Our findings support a negligible role of human activity in forcing glacier recession at the end of the Little Ice Age, highlighting the role of natural drivers.
Julien Seguinot, Susan Ivy-Ochs, Guillaume Jouvet, Matthias Huss, Martin Funk, and Frank Preusser
The Cryosphere, 12, 3265–3285, https://doi.org/10.5194/tc-12-3265-2018, https://doi.org/10.5194/tc-12-3265-2018, 2018
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About 25 000 years ago, Alpine glaciers filled most of the valleys and even extended onto the plains. In this study, with help from traces left by glaciers on the landscape, we use a computer model that contains knowledge of glacier physics based on modern observations of Greenland and Antarctica and laboratory experiments on ice, and one of the fastest computers in the world, to attempt a reconstruction of the evolution of Alpine glaciers through time from 120 000 years ago to today.
Dimitri Osmont, Isabel A. Wendl, Loïc Schmidely, Michael Sigl, Carmen P. Vega, Elisabeth Isaksson, and Margit Schwikowski
Atmos. Chem. Phys., 18, 12777–12795, https://doi.org/10.5194/acp-18-12777-2018, https://doi.org/10.5194/acp-18-12777-2018, 2018
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This study presents the first long-term and high-resolution refractory black carbon (rBC) ice core record from Svalbard, spanning the last 800 years. Our results show that rBC has had a predominant anthropogenic origin since the beginning of the Industrial Revolution in Europe and that rBC concentrations have been declining in the last 40 years. We discuss the impact of 20th century snowmelt on our record. We reconstruct biomass burning trends prior to 1800 by using a multi-proxy approach.
Anina Gilgen, Carole Adolf, Sandra O. Brugger, Luisa Ickes, Margit Schwikowski, Jacqueline F. N. van Leeuwen, Willy Tinner, and Ulrike Lohmann
Atmos. Chem. Phys., 18, 11813–11829, https://doi.org/10.5194/acp-18-11813-2018, https://doi.org/10.5194/acp-18-11813-2018, 2018
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Microscopic charcoal particles are fire-specific tracers, which are presently the primary source for reconstructing past fire activity. In this study, we implement microscopic charcoal particles into a global aerosol–climate model to better understand the transport of charcoal on a large scale. We find that the model captures a significant portion of the spatial variability but fails to reproduce the extreme variability observed in the charcoal data.
Jilu Li, Jose A. Vélez González, Carl Leuschen, Ayyangar Harish, Prasad Gogineni, Maurine Montagnat, Ilka Weikusat, Fernando Rodriguez-Morales, and John Paden
The Cryosphere, 12, 2689–2705, https://doi.org/10.5194/tc-12-2689-2018, https://doi.org/10.5194/tc-12-2689-2018, 2018
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Ice properties inferred from multi-polarization measurements can provide insight into ice strain, viscosity, and ice flow. The Center for Remote Sensing of Ice Sheets used a ground-based radar for multi-channel and multi-polarization measurements at the NEEM site. This paper describes the radar system, antenna configurations, data collection, and processing and analysis of this data set. Comparisons between the radar observations, simulations, and ice core fabric data are in very good agreement.
Shugui Hou, Theo M. Jenk, Wangbin Zhang, Chaomin Wang, Shuangye Wu, Yetang Wang, Hongxi Pang, and Margit Schwikowski
The Cryosphere, 12, 2341–2348, https://doi.org/10.5194/tc-12-2341-2018, https://doi.org/10.5194/tc-12-2341-2018, 2018
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We present multiple lines of evidence indicating that the Chongce ice cores drilled from the northwestern Tibetan Plateau reaches back only to the early Holocene. This result is at least, 1 order of magnitude younger than the nearby Guliya ice core (~30 km away from the Chongce ice core drilling site) but similar to other Tibetan ice cores. Thus it is necessary to explore multiple dating techniques to confirm the age ranges of the Tibetan ice cores.
Mackenzie M. Grieman, Murat Aydin, Elisabeth Isaksson, Margit Schwikowski, and Eric S. Saltzman
Clim. Past, 14, 637–651, https://doi.org/10.5194/cp-14-637-2018, https://doi.org/10.5194/cp-14-637-2018, 2018
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This study presents organic acid levels in an ice core from Svalbard over the past 800 years. These acids are produced from wildfire emissions and transported as aerosol. Organic acid levels are high early in the record and decline until the 20th century. Siberia and Europe are likely the primary source regions of the fire emissions. The data are similar to those from a Siberian ice core prior to 1400 CE. The timing of the divergence after 1400 CE is similar to a shift in North Atlantic climate.
Johanna Kerch, Anja Diez, Ilka Weikusat, and Olaf Eisen
The Cryosphere, 12, 1715–1734, https://doi.org/10.5194/tc-12-1715-2018, https://doi.org/10.5194/tc-12-1715-2018, 2018
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We investigate the effect of crystal anisotropy on seismic velocities in glacier ice by calculating seismic phase velocities using the exact c axis angles to describe the crystal orientations in ice-core samples for an alpine and a polar ice core. Our results provide uncertainty estimates for earlier established approximative calculations. Additionally, our findings highlight the variation in seismic velocity at non-vertical incidence as a function of the horizontal azimuth of the seismic plane.
Carmen Paulina Vega, Elisabeth Isaksson, Elisabeth Schlosser, Dmitry Divine, Tõnu Martma, Robert Mulvaney, Anja Eichler, and Margit Schwikowski-Gigar
The Cryosphere, 12, 1681–1697, https://doi.org/10.5194/tc-12-1681-2018, https://doi.org/10.5194/tc-12-1681-2018, 2018
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Ions were measured in firn and ice cores from Fimbul Ice Shelf, Antarctica, to evaluate sea-salt loads. A significant sixfold increase in sea salts was found in the S100 core after 1950s which suggests that it contains a more local sea-salt signal, dominated by processes during sea-ice formation in the neighbouring waters. In contrast, firn cores from three ice rises register the larger-scale signal of atmospheric flow conditions and transport of sea-salt aerosols produced over open water.
Florian Amann, Valentin Gischig, Keith Evans, Joseph Doetsch, Reza Jalali, Benoît Valley, Hannes Krietsch, Nathan Dutler, Linus Villiger, Bernard Brixel, Maria Klepikova, Anniina Kittilä, Claudio Madonna, Stefan Wiemer, Martin O. Saar, Simon Loew, Thomas Driesner, Hansruedi Maurer, and Domenico Giardini
Solid Earth, 9, 115–137, https://doi.org/10.5194/se-9-115-2018, https://doi.org/10.5194/se-9-115-2018, 2018
Pascal Bohleber, Helene Hoffmann, Johanna Kerch, Leo Sold, and Andrea Fischer
The Cryosphere, 12, 401–412, https://doi.org/10.5194/tc-12-401-2018, https://doi.org/10.5194/tc-12-401-2018, 2018
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In this study we use an existing ice cave at Chli Titlis (3030 m, central Switzerland) to obtain direct access to ice at the glacier base. Using standard glaciological tools as well as the analysis of the isotopic and physical properties we demonstrate that stagnant cold ice conditions still exist fairly unchanged more than 25 years after a pioneering exploration. Our radiocarbon dating of the basal ice indicates that Chli Titlis has likely been ice-covered for about the last 5000 years.
Valentin Samuel Gischig, Joseph Doetsch, Hansruedi Maurer, Hannes Krietsch, Florian Amann, Keith Frederick Evans, Morteza Nejati, Mohammadreza Jalali, Benoît Valley, Anne Christine Obermann, Stefan Wiemer, and Domenico Giardini
Solid Earth, 9, 39–61, https://doi.org/10.5194/se-9-39-2018, https://doi.org/10.5194/se-9-39-2018, 2018
Ilka Weikusat, Ernst-Jan N. Kuiper, Gill M. Pennock, Sepp Kipfstuhl, and Martyn R. Drury
Solid Earth, 8, 883–898, https://doi.org/10.5194/se-8-883-2017, https://doi.org/10.5194/se-8-883-2017, 2017
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Understanding the flow of large ice masses on Earth is a major challenge in our changing climate. Deformation mechanisms are governed by the strong anisotropy of ice. As anisotropy is currently moving into the focus of ice sheet flow studies, we provide a detailed analysis of microstructure data from natural ice core samples which directly relate to anisotropic plasticity. Our findings reveal surprising dislocation activity which seems to contradict the concept of macroscopic ice anisotropy.
Jan Eichler, Ina Kleitz, Maddalena Bayer-Giraldi, Daniela Jansen, Sepp Kipfstuhl, Wataru Shigeyama, Christian Weikusat, and Ilka Weikusat
The Cryosphere, 11, 1075–1090, https://doi.org/10.5194/tc-11-1075-2017, https://doi.org/10.5194/tc-11-1075-2017, 2017
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This study contributes to investigations of the effect of impurities on ice microstructure and flow properties. For the first time we mapped over 5000 micro-inclusions in four samples from the EDML and NEEM polar ice cores. The particle distributions show no correlation with grain boundaries and thus we conclude that particle pinning plays only a secondary role for the microstructure evolution. Alternative mechanisms are discussed.
Guillaume Jouvet, Yvo Weidmann, Julien Seguinot, Martin Funk, Takahiro Abe, Daiki Sakakibara, Hakime Seddik, and Shin Sugiyama
The Cryosphere, 11, 911–921, https://doi.org/10.5194/tc-11-911-2017, https://doi.org/10.5194/tc-11-911-2017, 2017
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In this study, we combine UAV (unmanned aerial vehicles) images taken over the Bowdoin Glacier, north-western Greenland, and a model describing the viscous motion of ice to track the propagation of crevasses responsible for the collapse of large icebergs at the glacier-ocean front (calving). This new technique allows us to explain the systematic calving pattern observed in spring and summer of 2015 and anticipate a possible rapid retreat in the future.
Melchior Grab, Beatriz Quintal, Eva Caspari, Hansruedi Maurer, and Stewart Greenhalgh
Solid Earth, 8, 255–279, https://doi.org/10.5194/se-8-255-2017, https://doi.org/10.5194/se-8-255-2017, 2017
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Hot fluids and hydraulically conductive rock formations are essential for the accessibility of geothermal resources. We use numerical modeling techniques to investigate how seismic waves change their shape in presence of these factors. We demonstrate how to parameterize such models depending on the local geology and as a function of depth. Finally, we show how the attenuation, i.e. the energy loss of the wave, can be indicative for permeable rock fractures saturated with a fluid of specific type.
Pascal Bohleber, Leo Sold, Douglas R. Hardy, Margit Schwikowski, Patrick Klenk, Andrea Fischer, Pascal Sirguey, Nicolas J. Cullen, Mariusz Potocki, Helene Hoffmann, and Paul Mayewski
The Cryosphere, 11, 469–482, https://doi.org/10.5194/tc-11-469-2017, https://doi.org/10.5194/tc-11-469-2017, 2017
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Our study is the first to use ground-penetrating radar (GPR) to investigate ice thickness and internal layering at Kilimanjaro’s largest ice body, the Northern Ice Field (NIF). For monitoring the ongoing ice loss, our ice thickness soundings allowed us to estimate the total ice volume remaining at NIF's southern portion. Englacial GPR reflections indicate undisturbed layers within NIF's center and provide a first link between age information obtained from ice coring and vertical wall sampling.
Rune Strand Ødegård, Atle Nesje, Ketil Isaksen, Liss Marie Andreassen, Trond Eiken, Margit Schwikowski, and Chiara Uglietti
The Cryosphere, 11, 17–32, https://doi.org/10.5194/tc-11-17-2017, https://doi.org/10.5194/tc-11-17-2017, 2017
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Despite numerous spectacular archaeological discoveries worldwide related to melting ice, governing processes related to ice patch development are still largely unexplored. We present new results from Jotunheimen in central southern Norway showing that the Juvfonne ice patch has existed continuously since ca. 7600 cal years BP. This is the oldest dating of ice in mainland Norway. Moss mats along the margin of Juvfonne in 2014 were covered by the expanding ice patch about 2000 years ago.
Chiara Uglietti, Alexander Zapf, Theo Manuel Jenk, Michael Sigl, Sönke Szidat, Gary Salazar, and Margit Schwikowski
The Cryosphere, 10, 3091–3105, https://doi.org/10.5194/tc-10-3091-2016, https://doi.org/10.5194/tc-10-3091-2016, 2016
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A meaningful interpretation of the climatic history contained in ice cores requires a precise chronology. For dating the older and deeper part of the glaciers, radiocarbon analysis can be used when organic matter such as plant or insect fragments are found in the ice. Since this happens rarely, a complementary dating tool, based on radiocarbon dating of the insoluble fraction of carbonaceous aerosols entrapped in the ice, allows for ice dating between 200 and more than 10 000 years.
Florian Steinbach, Paul D. Bons, Albert Griera, Daniela Jansen, Maria-Gema Llorens, Jens Roessiger, and Ilka Weikusat
The Cryosphere, 10, 3071–3089, https://doi.org/10.5194/tc-10-3071-2016, https://doi.org/10.5194/tc-10-3071-2016, 2016
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How glaciers or ice sheets flow is a result of microscopic processes controlled by the properties of individual ice crystals. We performed computer simulations on these processes and the effect of air bubbles between crystals. The simulations show that small-scale ice deformation is locally stronger than in other regions, which is enhanced by bubbles. This causes the ice crystals to recrystallise and change their properties in a way that potentially also affects the large-scale flow properties.
Paolo Gabrielli, Carlo Barbante, Giuliano Bertagna, Michele Bertó, Daniel Binder, Alberto Carton, Luca Carturan, Federico Cazorzi, Giulio Cozzi, Giancarlo Dalla Fontana, Mary Davis, Fabrizio De Blasi, Roberto Dinale, Gianfranco Dragà, Giuliano Dreossi, Daniela Festi, Massimo Frezzotti, Jacopo Gabrieli, Stephan P. Galos, Patrick Ginot, Petra Heidenwolf, Theo M. Jenk, Natalie Kehrwald, Donald Kenny, Olivier Magand, Volkmar Mair, Vladimir Mikhalenko, Ping Nan Lin, Klaus Oeggl, Gianni Piffer, Mirko Rinaldi, Ulrich Schotterer, Margit Schwikowski, Roberto Seppi, Andrea Spolaor, Barbara Stenni, David Tonidandel, Chiara Uglietti, Victor Zagorodnov, Thomas Zanoner, and Piero Zennaro
The Cryosphere, 10, 2779–2797, https://doi.org/10.5194/tc-10-2779-2016, https://doi.org/10.5194/tc-10-2779-2016, 2016
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New ice cores were extracted from Alto dell'Ortles, the highest glacier of South Tyrol in the Italian Alps, to check whether prehistoric ice, which is coeval to the famous 5300-yr-old Tyrolean Iceman, is still preserved in this region. Dating of the ice cores confirms the hypothesis and indicates the drilling site has been glaciated since the end of the Northern Hemisphere Climatic Optimum (7000 yrs BP). We also infer that an unprecedented acceleration of the glacier flow has recently begun.
Carmen P. Vega, Elisabeth Schlosser, Dmitry V. Divine, Jack Kohler, Tõnu Martma, Anja Eichler, Margit Schwikowski, and Elisabeth Isaksson
The Cryosphere, 10, 2763–2777, https://doi.org/10.5194/tc-10-2763-2016, https://doi.org/10.5194/tc-10-2763-2016, 2016
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Surface mass balance and water stable isotopes from firn cores on three ice rises at Fimbul Ice Shelf are reported. The results suggest that the ice rises are suitable sites for the retrieval of longer firn and ice cores. The first deuterium excess data for the area suggests a possible role of seasonal moisture transport changes on the annual isotopic signal. Large-scale atmospheric circulation patterns most likely provide the dominant influence on water stable isotope ratios at the sites.
Patrick Becker, Julien Seguinot, Guillaume Jouvet, and Martin Funk
Geogr. Helv., 71, 173–187, https://doi.org/10.5194/gh-71-173-2016, https://doi.org/10.5194/gh-71-173-2016, 2016
Carmen P. Vega, Veijo A. Pohjola, Emilie Beaudon, Björn Claremar, Ward J. J. van Pelt, Rickard Pettersson, Elisabeth Isaksson, Tõnu Martma, Margit Schwikowski, and Carl E. Bøggild
The Cryosphere, 10, 961–976, https://doi.org/10.5194/tc-10-961-2016, https://doi.org/10.5194/tc-10-961-2016, 2016
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To quantify post-depositional relocation of major ions by meltwater in snow and firn at Lomonosovfonna, Svalbard, consecutive ice cores drilled at this site were used to construct a synthetic core. The relocation length of most of the ions was on the order of 1 m between 2007 and 2010. Considering the ionic relocation lengths and annual melt percentages, we estimate that the atmospheric ionic signal remains preserved in recently drilled Lomonosovfonna ice cores at an annual or bi-annual resolution.
D. Jansen, M.-G. Llorens, J. Westhoff, F. Steinbach, S. Kipfstuhl, P. D. Bons, A. Griera, and I. Weikusat
The Cryosphere, 10, 359–370, https://doi.org/10.5194/tc-10-359-2016, https://doi.org/10.5194/tc-10-359-2016, 2016
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In this study we present examples of typical small-scale folds observed in the NEEM ice core, North Greenland, and discuss their characteristics. Numerical modelling of viscoplastic deformation and dynamic recrystallisation was used to improve the understanding of the formation of the observed structures under simple shear boundary conditions. We conclude that the folds originate from bands of grains with a tilted lattice relative to the strong lattice preferred orientation below 1500 m depth.
C. Müller-Tautges, A. Eichler, M. Schwikowski, G. B. Pezzatti, M. Conedera, and T. Hoffmann
Atmos. Chem. Phys., 16, 1029–1043, https://doi.org/10.5194/acp-16-1029-2016, https://doi.org/10.5194/acp-16-1029-2016, 2016
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The paper focuses on the determination and interpretation of historic records of organic compounds in an ice core from Grenzgletscher in the southern Swiss Alps, covering the time period from 1942 to 1993. The resulting long-term records of organic species were found to be influenced by the forest fire history in southern Switzerland, anthropogenic emissions, as well as changing mineral dust transport to the drilling site.
J. Gabbi, M. Huss, A. Bauder, F. Cao, and M. Schwikowski
The Cryosphere, 9, 1385–1400, https://doi.org/10.5194/tc-9-1385-2015, https://doi.org/10.5194/tc-9-1385-2015, 2015
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Light-absorbing impurities in snow and ice increase the absorption of solar radiation and thus enhance melting. We investigated the effect of Saharan dust and black carbon on the mass balance of an Alpine glacier over 1914-2014. Snow impurities increased melt by 15-19% depending on the location on the glacier. From the accumulation area towards the equilibrium line, the effect of impurities increased as more frequent years with negative mass balance led to a re-exposure of dust-enriched layers.
I. A. Wendl, A. Eichler, E. Isaksson, T. Martma, and M. Schwikowski
Atmos. Chem. Phys., 15, 7287–7300, https://doi.org/10.5194/acp-15-7287-2015, https://doi.org/10.5194/acp-15-7287-2015, 2015
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Nitrate and ammonium ice core records from Lomonosovfonna, Svalbard, indicated anthropogenic pollution from Eurasia as major source during the 20th century. In pre-industrial times nitrate is correlated with methane sulfonate, which we explain with a fertilising effect, presumably triggered by enhanced atmospheric nitrogen input to the ocean. Eurasia was likely the main source area also of pre-industrial nitrate, but for ammonium, biogenic emissions from Siberian boreal forests were dominant.
S. Kang, F. Wang, U. Morgenstern, Y. Zhang, B. Grigholm, S. Kaspari, M. Schwikowski, J. Ren, T. Yao, D. Qin, and P. A. Mayewski
The Cryosphere, 9, 1213–1222, https://doi.org/10.5194/tc-9-1213-2015, https://doi.org/10.5194/tc-9-1213-2015, 2015
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L. Sold, M. Huss, A. Eichler, M. Schwikowski, and M. Hoelzle
The Cryosphere, 9, 1075–1087, https://doi.org/10.5194/tc-9-1075-2015, https://doi.org/10.5194/tc-9-1075-2015, 2015
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This study presents a method for estimating annual accumulation rates on a temperate Alpine glacier based on the interpretation of internal reflection horizons in helicopter-borne ground-penetrating radar (GPR) data. In combination with a simple model for firn densification and refreezing of meltwater, GPR can be used not only to complement existing mass balance monitoring programmes but also to retrospectively extend newly initiated time series.
A. Diez, O. Eisen, C. Hofstede, A. Lambrecht, C. Mayer, H. Miller, D. Steinhage, T. Binder, and I. Weikusat
The Cryosphere, 9, 385–398, https://doi.org/10.5194/tc-9-385-2015, https://doi.org/10.5194/tc-9-385-2015, 2015
Y.-L. Zhang, R.-J. Huang, I. El Haddad, K.-F. Ho, J.-J. Cao, Y. Han, P. Zotter, C. Bozzetti, K. R. Daellenbach, F. Canonaco, J. G. Slowik, G. Salazar, M. Schwikowski, J. Schnelle-Kreis, G. Abbaszade, R. Zimmermann, U. Baltensperger, A. S. H. Prévôt, and S. Szidat
Atmos. Chem. Phys., 15, 1299–1312, https://doi.org/10.5194/acp-15-1299-2015, https://doi.org/10.5194/acp-15-1299-2015, 2015
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Source apportionment of fine carbonaceous aerosols using radiocarbon and other organic markers measurements during 2013 winter haze episodes was conducted at four megacities in China. Our results demonstrate that fossil emissions predominate EC with a mean contribution of 75±8%, whereas non-fossil sources account for 55±10% of OC; and the increment of TC on heavily polluted days was mainly driven by the increase of secondary OC from both fossil-fuel and non-fossil emissions.
P. Zotter, V. G. Ciobanu, Y. L. Zhang, I. El-Haddad, M. Macchia, K. R. Daellenbach, G. A. Salazar, R.-J. Huang, L. Wacker, C. Hueglin, A. Piazzalunga, P. Fermo, M. Schwikowski, U. Baltensperger, S. Szidat, and A. S. H. Prévôt
Atmos. Chem. Phys., 14, 13551–13570, https://doi.org/10.5194/acp-14-13551-2014, https://doi.org/10.5194/acp-14-13551-2014, 2014
I. A. Wendl, J. A. Menking, R. Färber, M. Gysel, S. D. Kaspari, M. J. G. Laborde, and M. Schwikowski
Atmos. Meas. Tech., 7, 2667–2681, https://doi.org/10.5194/amt-7-2667-2014, https://doi.org/10.5194/amt-7-2667-2014, 2014
S. Kaspari, T. H. Painter, M. Gysel, S. M. Skiles, and M. Schwikowski
Atmos. Chem. Phys., 14, 8089–8103, https://doi.org/10.5194/acp-14-8089-2014, https://doi.org/10.5194/acp-14-8089-2014, 2014
M. Montagnat, N. Azuma, D. Dahl-Jensen, J. Eichler, S. Fujita, F. Gillet-Chaulet, S. Kipfstuhl, D. Samyn, A. Svensson, and I. Weikusat
The Cryosphere, 8, 1129–1138, https://doi.org/10.5194/tc-8-1129-2014, https://doi.org/10.5194/tc-8-1129-2014, 2014
I. Mariani, A. Eichler, T. M. Jenk, S. Brönnimann, R. Auchmann, M. C. Leuenberger, and M. Schwikowski
Clim. Past, 10, 1093–1108, https://doi.org/10.5194/cp-10-1093-2014, https://doi.org/10.5194/cp-10-1093-2014, 2014
T. Papina, T. Blyakharchuk, A. Eichler, N. Malygina, E. Mitrofanova, and M. Schwikowski
Clim. Past, 9, 2399–2411, https://doi.org/10.5194/cp-9-2399-2013, https://doi.org/10.5194/cp-9-2399-2013, 2013
M. Schwikowski, M. Schläppi, P. Santibañez, A. Rivera, and G. Casassa
The Cryosphere, 7, 1635–1644, https://doi.org/10.5194/tc-7-1635-2013, https://doi.org/10.5194/tc-7-1635-2013, 2013
S. Brönnimann, I. Mariani, M. Schwikowski, R. Auchmann, and A. Eichler
Clim. Past, 9, 2013–2022, https://doi.org/10.5194/cp-9-2013-2013, https://doi.org/10.5194/cp-9-2013-2013, 2013
J. Kropáček, N. Neckel, and A. Bauder
The Cryosphere Discuss., https://doi.org/10.5194/tcd-7-3261-2013, https://doi.org/10.5194/tcd-7-3261-2013, 2013
Preprint withdrawn
Related subject area
Discipline: Glaciers | Subject: Alpine Glaciers
Brief communication: Recent estimates of glacier mass loss for western North America from laser altimetry
The Aneto glacier's (Central Pyrenees) evolution from 1981 to 2022: ice loss observed from historic aerial image photogrammetry and remote sensing techniques
Modelling point mass balance for the glaciers of the Central European Alps using machine learning techniques
Consistent histories of anthropogenic western European air pollution preserved in different Alpine ice cores
Brief communication: Non-linear sensitivity of glacier mass balance to climate attested by temperature-index models
Halving of Swiss glacier volume since 1931 observed from terrestrial image photogrammetry
Land- to lake-terminating transition triggers dynamic thinning of a Bhutanese glacier
Brief communication: A framework to classify glaciers for water resource evaluation and management in the Southern Andes
Strong acceleration of glacier area loss in the Greater Caucasus between 2000 and 2020
Ice volume and basal topography estimation using geostatistical methods and ground-penetrating radar measurements: application to the Tsanfleuron and Scex Rouge glaciers, Swiss Alps
Significant mass loss in the accumulation area of the Adamello glacier indicated by the chronology of a 46 m ice core
Brief communication: Do 1.0, 1.5, or 2.0 °C matter for the future evolution of Alpine glaciers?
A new automatic approach for extracting glacier centerlines based on Euclidean allocation
Spatially and temporally resolved ice loss in High Mountain Asia and the Gulf of Alaska observed by CryoSat-2 swath altimetry between 2010 and 2019
Debris cover and the thinning of Kennicott Glacier, Alaska: in situ measurements, automated ice cliff delineation and distributed melt estimates
Small-scale spatial variability in bare-ice reflectance at Jamtalferner, Austria
Numerical modeling of the dynamics of the Mer de Glace glacier, French Alps: comparison with past observations and forecasting of near-future evolution
Monitoring the seasonal changes of an englacial conduit network using repeated ground-penetrating radar measurements
Possible biases in scaling-based estimates of glacier change: a case study in the Himalaya
Spatial and temporal variations in glacier aerodynamic surface roughness during the melting season, as estimated at the August-one ice cap, Qilian mountains, China
Strong changes in englacial temperatures despite insignificant changes in ice thickness at Dôme du Goûter glacier (Mont Blanc area)
Supra-glacial debris cover changes in the Greater Caucasus from 1986 to 2014
Glacier thickness estimations of alpine glaciers using data and modeling constraints
Unravelling the evolution of Zmuttgletscher and its debris cover since the end of the Little Ice Age
Modelling the future evolution of glaciers in the European Alps under the EURO-CORDEX RCM ensemble
Robust uncertainty assessment of the spatio-temporal transferability of glacier mass and energy balance models
Impacts of topographic shading on direct solar radiation for valley glaciers in complex topography
19th century glacier retreat in the Alps preceded the emergence of industrial black carbon deposition on high-alpine glaciers
Iron oxides in the cryoconite of glaciers on the Tibetan Plateau: abundance, speciation and implications
Numerical reconstructions of the flow and basal conditions of the Rhine glacier, European Central Alps, at the Last Glacial Maximum
Brian Menounos, Alex Gardner, Caitlyn Florentine, and Andrew Fountain
The Cryosphere, 18, 889–894, https://doi.org/10.5194/tc-18-889-2024, https://doi.org/10.5194/tc-18-889-2024, 2024
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Glaciers in western North American outside of Alaska are often overlooked in global studies because their potential to contribute to changes in sea level is small. Nonetheless, these glaciers represent important sources of freshwater, especially during times of drought. We show that these glaciers lost mass at a rate of about 12 Gt yr-1 for about the period 2013–2021; the rate of mass loss over the period 2018–2022 was similar.
Ixeia Vidaller, Eñaut Izagirre, Luis Mariano del Rio, Esteban Alonso-González, Francisco Rojas-Heredia, Enrique Serrano, Ana Moreno, Juan Ignacio López-Moreno, and Jesús Revuelto
The Cryosphere, 17, 3177–3192, https://doi.org/10.5194/tc-17-3177-2023, https://doi.org/10.5194/tc-17-3177-2023, 2023
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The Aneto glacier, the largest glacier in the Pyrenees, has shown continuous surface and ice thickness losses in the last decades. In this study, we examine changes in its surface and ice thickness for 1981–2022 and the remaining ice thickness in 2020. During these 41 years, the glacier has shrunk by 64.7 %, and the ice thickness has decreased by 30.5 m on average. The mean ice thickness in 2022 was 11.9 m, compared to 32.9 m in 1981. The results highlight the critical situation of the glacier.
Ritu Anilkumar, Rishikesh Bharti, Dibyajyoti Chutia, and Shiv Prasad Aggarwal
The Cryosphere, 17, 2811–2828, https://doi.org/10.5194/tc-17-2811-2023, https://doi.org/10.5194/tc-17-2811-2023, 2023
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Our analysis demonstrates the capability of machine learning models in estimating glacier mass balance in terms of performance metrics and dataset availability. Feature importance analysis suggests that ablation features are significant. This is in agreement with the predominantly negative mass balance observations. We show that ensemble tree models typically depict the best performance. However, neural network models are preferable for biased inputs and kernel-based models for smaller datasets.
Anja Eichler, Michel Legrand, Theo M. Jenk, Susanne Preunkert, Camilla Andersson, Sabine Eckhardt, Magnuz Engardt, Andreas Plach, and Margit Schwikowski
The Cryosphere, 17, 2119–2137, https://doi.org/10.5194/tc-17-2119-2023, https://doi.org/10.5194/tc-17-2119-2023, 2023
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We investigate how a 250-year history of the emission of air pollutants (major inorganic aerosol constituents, black carbon, and trace species) is preserved in ice cores from four sites in the European Alps. The observed uniform timing in species-dependent longer-term concentration changes reveals that the different ice-core records provide a consistent, spatially representative signal of the pollution history from western European countries.
Christian Vincent and Emmanuel Thibert
The Cryosphere, 17, 1989–1995, https://doi.org/10.5194/tc-17-1989-2023, https://doi.org/10.5194/tc-17-1989-2023, 2023
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Temperature-index models have been widely used for glacier mass projections in the future. The ability of these models to capture non-linear responses of glacier mass balance (MB) to high deviations in air temperature and solid precipitation has recently been questioned by mass balance simulations employing advanced machine-learning techniques. Here, we confirmed that temperature-index models are capable of detecting non-linear responses of glacier MB to temperature and precipitation changes.
Erik Schytt Mannerfelt, Amaury Dehecq, Romain Hugonnet, Elias Hodel, Matthias Huss, Andreas Bauder, and Daniel Farinotti
The Cryosphere, 16, 3249–3268, https://doi.org/10.5194/tc-16-3249-2022, https://doi.org/10.5194/tc-16-3249-2022, 2022
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How glaciers have responded to climate change over the last 20 years is well-known, but earlier data are much more scarce. We change this in Switzerland by using 22 000 photographs taken from mountain tops between the world wars and find a halving of Swiss glacier volume since 1931. This was done through new automated processing techniques that we created. The data are interesting for more than just glaciers, such as mapping forest changes, landslides, and human impacts on the terrain.
Yota Sato, Koji Fujita, Hiroshi Inoue, Akiko Sakai, and Karma
The Cryosphere, 16, 2643–2654, https://doi.org/10.5194/tc-16-2643-2022, https://doi.org/10.5194/tc-16-2643-2022, 2022
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We investigate fluctuations in Bhutanese lake-terminating glaciers focusing on the dynamics change before and after proglacial lake formation at Thorthormi Glacier (TG) based on photogrammetry, satellite, and GPS surveys. The thinning rate of TG became double compared to before proglacial lake formation, and the flow velocity has also sped up considerably. Those changes would be due to the reduction in longitudinal ice compression by the detachment of the glacier terminus from the end moraine.
Nicole Schaffer and Shelley MacDonell
The Cryosphere, 16, 1779–1791, https://doi.org/10.5194/tc-16-1779-2022, https://doi.org/10.5194/tc-16-1779-2022, 2022
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Over the last 2 decades the importance of Andean glaciers, particularly as water resources, has been recognized in both scientific literature and the public sphere. This has led to the inclusion of glaciers in environmental impact assessment and the development of glacier protection laws. We propose three categories that group glaciers based on their environmental sensitivity to hopefully help facilitate the effective application of these measures and evaluation of water resources in general.
Levan G. Tielidze, Gennady A. Nosenko, Tatiana E. Khromova, and Frank Paul
The Cryosphere, 16, 489–504, https://doi.org/10.5194/tc-16-489-2022, https://doi.org/10.5194/tc-16-489-2022, 2022
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The new Caucasus glacier inventory derived from manual delineation of glacier outlines based on medium-resolution (Landsat, Sentinel) and high-resolution (SPOT) satellite imagery shows the accelerated glacier area loss over the last 2 decades (2000–2020). This new glacier inventory will improve our understanding of climate change impacts at a regional scale and support related modelling studies by providing high-quality validation data.
Alexis Neven, Valentin Dall'Alba, Przemysław Juda, Julien Straubhaar, and Philippe Renard
The Cryosphere, 15, 5169–5186, https://doi.org/10.5194/tc-15-5169-2021, https://doi.org/10.5194/tc-15-5169-2021, 2021
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We present and compare different geostatistical methods for underglacial bedrock interpolation. Variogram-based interpolations are compared with a multipoint statistics approach on both test cases and real glaciers. Using the modeled bedrock, the ice volume for the Scex Rouge and Tsanfleuron glaciers (Swiss Alps) was estimated to be 113.9 ± 1.6 million cubic meters. Complex karstic geomorphological features are reproduced and can be used to improve the precision of underglacial flow estimation.
Daniela Festi, Margit Schwikowski, Valter Maggi, Klaus Oeggl, and Theo Manuel Jenk
The Cryosphere, 15, 4135–4143, https://doi.org/10.5194/tc-15-4135-2021, https://doi.org/10.5194/tc-15-4135-2021, 2021
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In our study we dated a 46 m deep ice core retrieved from the Adamello glacier (Central Italian Alps). We obtained a timescale combining the results of radionuclides 210Pb and 137Cs with annual layer counting derived from pollen and refractory black carbon concentrations. Our results indicate that the surface of the glacier is older than the drilling date of 2016 by about 20 years, therefore revealing that the glacier is at high risk of collapsing under current climate warming conditions.
Loris Compagno, Sarah Eggs, Matthias Huss, Harry Zekollari, and Daniel Farinotti
The Cryosphere, 15, 2593–2599, https://doi.org/10.5194/tc-15-2593-2021, https://doi.org/10.5194/tc-15-2593-2021, 2021
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Recently, discussions have focused on the difference in limiting the increase in global average temperatures to below 1.0, 1.5, or 2.0 °C compared to preindustrial levels. Here, we assess the impacts that such different scenarios would have on both the future evolution of glaciers in the European Alps and the water resources they provide. Our results show that the different temperature targets have important implications for the changes predicted until 2100.
Dahong Zhang, Xiaojun Yao, Hongyu Duan, Shiyin Liu, Wanqin Guo, Meiping Sun, and Dazhi Li
The Cryosphere, 15, 1955–1973, https://doi.org/10.5194/tc-15-1955-2021, https://doi.org/10.5194/tc-15-1955-2021, 2021
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Glacier centerlines are crucial input for many glaciological applications. We propose a new algorithm to derive glacier centerlines and implement the corresponding program in Python language. Application of this method to 48 571 glaciers in the second Chinese glacier inventory automatically yielded the corresponding glacier centerlines with an average computing time of 20.96 s, a success rate of 100 % and a comprehensive accuracy of 94.34 %.
Livia Jakob, Noel Gourmelen, Martin Ewart, and Stephen Plummer
The Cryosphere, 15, 1845–1862, https://doi.org/10.5194/tc-15-1845-2021, https://doi.org/10.5194/tc-15-1845-2021, 2021
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Glaciers and ice caps are currently the largest contributor to sea level rise. Global monitoring of these regions is a challenging task, and significant differences remain between current estimates. This study looks at glacier changes in High Mountain Asia and the Gulf of Alaska using a new technique, which for the first time makes the use of satellite radar altimetry for mapping ice mass loss over mountain glacier regions possible.
Leif S. Anderson, William H. Armstrong, Robert S. Anderson, and Pascal Buri
The Cryosphere, 15, 265–282, https://doi.org/10.5194/tc-15-265-2021, https://doi.org/10.5194/tc-15-265-2021, 2021
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Many glaciers are thinning rapidly beneath debris cover (loose rock) that reduces melt, including Kennicott Glacier in Alaska. This contradiction has been explained by melt hotspots, such as ice cliffs, scattered within the debris cover. However, at Kennicott Glacier declining ice flow explains the rapid thinning. Through this study, Kennicott Glacier is now the first glacier in Alaska, and the largest glacier globally, where melt across its debris-covered tongue has been rigorously quantified.
Lea Hartl, Lucia Felbauer, Gabriele Schwaizer, and Andrea Fischer
The Cryosphere, 14, 4063–4081, https://doi.org/10.5194/tc-14-4063-2020, https://doi.org/10.5194/tc-14-4063-2020, 2020
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When glaciers become snow-free in summer, darker glacier ice is exposed. The ice surface is darker than snow and absorbs more radiation, which increases ice melt. We measured how much radiation is reflected at different wavelengths in the ablation zone of Jamtalferner, Austria. Due to impurities and water on the ice surface there are large variations in reflectance. Landsat 8 and Sentinel-2 surface reflectance products do not capture the full range of reflectance found on the glacier.
Vincent Peyaud, Coline Bouchayer, Olivier Gagliardini, Christian Vincent, Fabien Gillet-Chaulet, Delphine Six, and Olivier Laarman
The Cryosphere, 14, 3979–3994, https://doi.org/10.5194/tc-14-3979-2020, https://doi.org/10.5194/tc-14-3979-2020, 2020
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Alpine glaciers are retreating at an accelerating rate in a warming climate. Numerical models allow us to study and anticipate these changes, but the performance of a model is difficult to evaluate. So we compared an ice flow model with the long dataset of observations obtained between 1979 and 2015 on Mer de Glace (Mont Blanc area). The model accurately reconstructs the past evolution of the glacier. We simulate the future evolution of Mer de Glace; it could retreat by 2 to 6 km by 2050.
Gregory Church, Melchior Grab, Cédric Schmelzbach, Andreas Bauder, and Hansruedi Maurer
The Cryosphere, 14, 3269–3286, https://doi.org/10.5194/tc-14-3269-2020, https://doi.org/10.5194/tc-14-3269-2020, 2020
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In this field study, we repeated ground-penetrating radar measurements over an active englacial channel network that transports meltwater through the glacier. We successfully imaged the englacial meltwater pathway and were able to delimitate the channel's shape. Meltwater from the glacier can impact the glacier's dynamics if it reaches the ice–bed interface, and therefore monitoring these englacial drainage networks is important to understand how these networks behave throughout a season.
Argha Banerjee, Disha Patil, and Ajinkya Jadhav
The Cryosphere, 14, 3235–3247, https://doi.org/10.5194/tc-14-3235-2020, https://doi.org/10.5194/tc-14-3235-2020, 2020
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Simple models of glacier dynamics based on volume–area scaling underestimate climate sensitivity and response time of glaciers. Consequently, they may predict a faster response and a smaller long-term glacier loss. These biases in scaling models are established theoretically and are analysed in detail by simulating the step response of a set of 703 Himalayan glaciers separately by three different models: a scaling model, a 2-D shallow-ice approximation model, and a linear-response model.
Junfeng Liu, Rensheng Chen, and Chuntan Han
The Cryosphere, 14, 967–984, https://doi.org/10.5194/tc-14-967-2020, https://doi.org/10.5194/tc-14-967-2020, 2020
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Glacier surface roughness during melting season was observed by manual and automatic photogrammetry. Surface roughness was larger at the snow and ice transition zone than in fully snow- or ice-covered areas. Persistent snowfall and rainfall both reduce surface roughness. High or rising turbulent heat as a component of surface energy balance tended to produce a smooth ice surface; low or decreasing turbulent heat tended to produce a rougher surface.
Christian Vincent, Adrien Gilbert, Bruno Jourdain, Luc Piard, Patrick Ginot, Vladimir Mikhalenko, Philippe Possenti, Emmanuel Le Meur, Olivier Laarman, and Delphine Six
The Cryosphere, 14, 925–934, https://doi.org/10.5194/tc-14-925-2020, https://doi.org/10.5194/tc-14-925-2020, 2020
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We observed very low glacier thickness changes over the last decades at very-high-elevation glaciated areas on Mont Blanc. Conversely, measurements performed in deep boreholes since 1994 reveal strong changes in englacial temperature reaching 1.5 °C at a depth of 50 m. We conclude that at such very high elevations, current changes in climate do not lead to visible changes in glacier thickness but cause invisible changes within the glacier in terms of englacial temperatures.
Levan G. Tielidze, Tobias Bolch, Roger D. Wheate, Stanislav S. Kutuzov, Ivan I. Lavrentiev, and Michael Zemp
The Cryosphere, 14, 585–598, https://doi.org/10.5194/tc-14-585-2020, https://doi.org/10.5194/tc-14-585-2020, 2020
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We present data of supra-glacial debris cover for 659 glaciers across the Greater Caucasus based on satellite images from the years 1986, 2000 and 2014. We combined semi-automated methods for mapping the clean ice with manual digitization of debris-covered glacier parts and calculated supra-glacial debris-covered area as the residual between these two maps. The distribution of the supra-glacial debris cover differs between northern and southern and between western, central and eastern Caucasus.
Lisbeth Langhammer, Melchior Grab, Andreas Bauder, and Hansruedi Maurer
The Cryosphere, 13, 2189–2202, https://doi.org/10.5194/tc-13-2189-2019, https://doi.org/10.5194/tc-13-2189-2019, 2019
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We have developed a novel procedure for glacier thickness estimations that combines traditional glaciological modeling constraints with ground-truth data, for example, those obtained with ground-penetrating radar (GPR) measurements. This procedure is very useful for determining ice volume when only limited data are available. Furthermore, we outline a strategy for acquiring GPR data on glaciers, such that the cost/benefit ratio is optimized.
Nico Mölg, Tobias Bolch, Andrea Walter, and Andreas Vieli
The Cryosphere, 13, 1889–1909, https://doi.org/10.5194/tc-13-1889-2019, https://doi.org/10.5194/tc-13-1889-2019, 2019
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Debris can partly protect glaciers from melting. But many debris-covered glaciers change similar to debris-free glaciers. To better understand the debris influence we investigated 150 years of evolution of Zmutt Glacier in Switzerland. We found an increase in debris extent over time and a link to glacier flow velocity changes. We also found an influence of debris on the melt locally, but only a small volume change reduction over the whole glacier, also because of the influence of ice cliffs.
Harry Zekollari, Matthias Huss, and Daniel Farinotti
The Cryosphere, 13, 1125–1146, https://doi.org/10.5194/tc-13-1125-2019, https://doi.org/10.5194/tc-13-1125-2019, 2019
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Glaciers in the European Alps play an important role in the hydrological cycle, act as a source for hydroelectricity and have a large touristic importance. We model the future evolution of all glaciers in the Alps with a novel model that combines both ice flow and melt processes. We find that under a limited warming scenario about one-third of the present-day ice volume will still be present by the end of the century, while under strong warming more than 90 % of the volume will be lost by 2100.
Tobias Zolles, Fabien Maussion, Stephan Peter Galos, Wolfgang Gurgiser, and Lindsey Nicholson
The Cryosphere, 13, 469–489, https://doi.org/10.5194/tc-13-469-2019, https://doi.org/10.5194/tc-13-469-2019, 2019
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A mass and energy balance model was subjected to sensitivity and uncertainty analysis on two different Alpine glaciers. The global sensitivity analysis allowed for a mass balance measurement independent assessment of the model sensitivity and functioned as a reduction of the model free parameter space. A novel approach of a multi-objective optimization estimates the uncertainty of the simulated mass balance and the energy fluxes. The final model uncertainty is up to 1300 kg m−3 per year.
Matthew Olson and Summer Rupper
The Cryosphere, 13, 29–40, https://doi.org/10.5194/tc-13-29-2019, https://doi.org/10.5194/tc-13-29-2019, 2019
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Solar radiation is the largest energy input for most alpine glaciers. However, many models oversimplify the influence of topographic shading. Also, no systematic studies have explored the variable impact of shading on glacier ice. We find that shading can significantly impact modeled solar radiation, particularly at low elevations, at high latitudes, and for glaciers with a north/south orientation. Excluding the effects of shading will overestimate modeled solar radiation for alpine glaciers.
Michael Sigl, Nerilie J. Abram, Jacopo Gabrieli, Theo M. Jenk, Dimitri Osmont, and Margit Schwikowski
The Cryosphere, 12, 3311–3331, https://doi.org/10.5194/tc-12-3311-2018, https://doi.org/10.5194/tc-12-3311-2018, 2018
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The fast retreat of Alpine glaciers since the mid-19th century documented in photographs is used as a symbol for the human impact on global climate, yet the key driving forces remain elusive. Here we argue that not industrial soot but volcanic eruptions were responsible for an apparently accelerated deglaciation starting in the 1850s. Our findings support a negligible role of human activity in forcing glacier recession at the end of the Little Ice Age, highlighting the role of natural drivers.
Zhiyuan Cong, Shaopeng Gao, Wancang Zhao, Xin Wang, Guangming Wu, Yulan Zhang, Shichang Kang, Yongqin Liu, and Junfeng Ji
The Cryosphere, 12, 3177–3186, https://doi.org/10.5194/tc-12-3177-2018, https://doi.org/10.5194/tc-12-3177-2018, 2018
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Cryoconites from glaciers on the Tibetan Plateau and surrounding area were studied for iron oxides. We found that goethite is the predominant iron oxide form. Using the abundance, speciation and optical properties of iron oxides, the total light absorption was quantitatively attributed to goethite, hematite, black carbon and organic matter. Such findings are essential to understand the relative significance of anthropogenic and natural impacts.
Denis Cohen, Fabien Gillet-Chaulet, Wilfried Haeberli, Horst Machguth, and Urs H. Fischer
The Cryosphere, 12, 2515–2544, https://doi.org/10.5194/tc-12-2515-2018, https://doi.org/10.5194/tc-12-2515-2018, 2018
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As part of an integrative study about the safety of repositories for radioactive waste under ice age conditions in Switzerland, we modeled the flow of ice of the Rhine glacier at the Last Glacial Maximum to determine conditions at the ice–bed interface. Results indicate that portions of the ice lobes were at the melting temperature and ice was sliding, two conditions necessary for erosion by glacier. Conditions at the bed of the ice lobes were affected by climate and also by topography.
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Short summary
We analyse the orientation of ice crystals in an Alpine glacier and compare this orientation with the ice flow direction. We found that the crystals orient in the direction of the largest stress which is in the flow direction in the upper parts of the glacier and in the vertical direction for deeper zones of the glacier. The grains cluster around this maximum stress direction, in particular four-point maxima, most likely as a result of recrystallisation under relatively warm conditions.
We analyse the orientation of ice crystals in an Alpine glacier and compare this orientation...
