Articles | Volume 15, issue 7
https://doi.org/10.5194/tc-15-3507-2021
© 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-15-3507-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
28 Jul 2021
Research article |
| 28 Jul 2021
| 28 Jul 2021
Acoustic velocity measurements for detecting the crystal orientation fabrics of a temperate ice core
Sebastian Hellmann
CORRESPONDING AUTHOR
Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland
Institute of Geophysics, ETH Zurich, Zurich, Switzerland
Melchior Grab
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
GZG Computational Geoscience, Georg-August University, Göttingen, Germany
Henning Löwe
WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
Andreas Bauder
Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland
Ilka Weikusat
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Department of Geosciences, Eberhard Karls University, Tübingen, Germany
Hansruedi Maurer
Institute of Geophysics, ETH Zurich, Zurich, Switzerland
Related authors
Sebastian Hellmann, Melchior Grab, Cedric Patzer, Andreas Bauder, and Hansruedi Maurer
Solid Earth, 14, 805–821, https://doi.org/10.5194/se-14-805-2023, https://doi.org/10.5194/se-14-805-2023, 2023
Short summary
Short summary
Acoustic waves are suitable to analyse the physical properties of the subsurface. For this purpose, boreholes are quite useful to deploy a source and receivers in the target area to get a comprehensive high-resolution dataset. However, when conducting such experiments in a subsurface such as glaciers that continuously move, the boreholes get deformed. In our study, we therefore developed a method that allows an analysis of the ice while considering deformations.
Sebastian Hellmann, Johanna Kerch, Ilka Weikusat, Andreas Bauder, Melchior Grab, Guillaume Jouvet, Margit Schwikowski, and Hansruedi Maurer
The Cryosphere, 15, 677–694, https://doi.org/10.5194/tc-15-677-2021, https://doi.org/10.5194/tc-15-677-2021, 2021
Short summary
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.
Kathrin Behnen, Marian Hertrich, Hansruedi Maurer, Alexis Shakas, Kai Bröker, Claire Epiney, María Blanch Jover, and Domenico Giardini
Solid Earth, 16, 333–350, https://doi.org/10.5194/se-16-333-2025, https://doi.org/10.5194/se-16-333-2025, 2025
Short summary
Short summary
Several cross-hole seismic surveys in the undisturbed Rotondo granite are used to analyze the seismic anisotropy in the Bedretto Lab, Switzerland. The P and S1 waves show a clear trend of faster velocities in the NE–SW direction and slower velocities perpendicular to it, indicating a tilted transverse isotropic velocity model. The symmetry plane is mostly aligned with the direction of maximum stress, but also the orientation of fractures is expected to influence the velocities.
Florian Painer, Sepp Kipfstuhl, Martyn Drury, Tsutomu Uchida, Johannes Freitag, and Ilka Weikusat
EGUsphere, https://doi.org/10.5194/egusphere-2025-633, https://doi.org/10.5194/egusphere-2025-633, 2025
Short summary
Short summary
Air clathrate hydrates trap ancient air in the deeper part of ice sheets. We use digital microscopy and automated image analysis to investigate the evolution of number, size and shape of air clathrate hydrates from 1250 m depth to the bottom of the ice sheet. We confirm the previously found relation of changes in number and size with past climate and find a connection of their shape to changes in ice deformation. The results will help to better understand air clathrate hydrates in deep ice.
Paul Dirk Bons, Yuanbang Hu, Maria-Gema Llorens, Steven Franke, Nicolas Stoll, Ilka Weikusat, Julien Wetshoff, and Yu Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3817, https://doi.org/10.5194/egusphere-2024-3817, 2025
Short summary
Short summary
What causes folds in ice layers from the km-scale down to the scale visible in drill core? Classical buckle folding due to variations in viscosity between layers, or the effect of mechanical anisotropy of ice due to an alignment of the crystal-lattice planes? Comparison of power spectra of folds in ice, a biotite schist, and numerical simulations show that folding in ice is due to the mechanical anisotropy, as there is no characteristic fold scale that would result from buckle folding.
Nicolas Stoll, Ilka Weikusat, Daniela Jansen, Paul Bons, Kyra Darányi, Julien Westhoff, Mária-Gema Llorens, David Wallis, Jan Eichler, Tomotaka Saruya, Tomoyuki Homma, Martyn Drury, Frank Wilhelms, Sepp Kipfstuhl, Dorthe Dahl-Jensen, and Johanna Kerch
EGUsphere, https://doi.org/10.5194/egusphere-2024-2653, https://doi.org/10.5194/egusphere-2024-2653, 2024
Short summary
Short summary
A better understanding of ice flow requires more observational data. The EastGRIP core is the first ice core through an active ice stream. We discuss crystal orientation data to determine the present deformation regimes. A comparison with other deep ice cores shows the unique properties of EastGRIP and that deep ice originates from the Eemian. We further show that the overall plug flow of NEGIS is characterised by many small-scale variations, which remain to be considered in ice-flow models.
Julien Westhoff, Johannes Freitag, Anaïs Orsi, Patricia Martinerie, Ilka Weikusat, Michael Dyonisius, Xavier Faïn, Kevin Fourteau, and Thomas Blunier
The Cryosphere, 18, 4379–4397, https://doi.org/10.5194/tc-18-4379-2024, https://doi.org/10.5194/tc-18-4379-2024, 2024
Short summary
Short summary
We study the EastGRIP area, Greenland, in detail with traditional and novel techniques. Due to the compaction of the ice, at a certain depth, atmospheric gases can no longer exchange, and the atmosphere is trapped in air bubbles in the ice. We find this depth by pumping air from a borehole, modeling, and using a new technique based on the optical appearance of the ice. Our results suggest that the close-off depth lies at around 58–61 m depth and more precisely at 58.3 m depth.
Benjamin Walter, Hagen Weigel, Sonja Wahl, and Henning Löwe
The Cryosphere, 18, 3633–3652, https://doi.org/10.5194/tc-18-3633-2024, https://doi.org/10.5194/tc-18-3633-2024, 2024
Short summary
Short summary
The topmost layer of a snowpack forms the interface to the atmosphere and is critical for the reflectance of solar radiation and avalanche formation. The effect of wind on the surface snow microstructure during precipitation events is poorly understood and quantified. We performed controlled lab experiments in a ring wind tunnel to systematically quantify the snow microstructure for different wind speeds, temperatures and precipitation intensities and to identify the relevant processes.
Kévin Fourteau, Johannes Freitag, Mika Malinen, and Henning Löwe
The Cryosphere, 18, 2831–2846, https://doi.org/10.5194/tc-18-2831-2024, https://doi.org/10.5194/tc-18-2831-2024, 2024
Short summary
Short summary
Understanding the settling of snow under its own weight has applications from avalanche forecasts to ice core interpretations. We study how this settling can be modeled using 3D images of the internal structure of snow and ice deformation mechanics. We found that classical ice mechanics, as used, for instance, in glacier flow, explain the compaction of dense polar snow but not that of lighter seasonal snow. How, exactly, the ice deforms during light snow compaction thus remains an open question.
Julien Meloche, Melody Sandells, Henning Löwe, Nick Rutter, Richard Essery, Ghislain Picard, Randall K. Scharien, Alexandre Langlois, Matthias Jaggi, Josh King, Peter Toose, Jérôme Bouffard, Alessandro Di Bella, and Michele Scagliola
EGUsphere, https://doi.org/10.5194/egusphere-2024-1583, https://doi.org/10.5194/egusphere-2024-1583, 2024
Preprint archived
Short summary
Short summary
Sea ice thickness is essential for climate studies. Radar altimetry has provided sea ice thickness measurement, but uncertainty arises from interaction of the signal with the snow cover. Therefore, modelling the signal interaction with the snow is necessary to improve retrieval. A radar model was used to simulate the radar signal from the snow-covered sea ice. This work paved the way to improved physical algorithm to retrieve snow depth and sea ice thickness for radar altimeter missions.
Anna Braun, Kévin Fourteau, and Henning Löwe
The Cryosphere, 18, 1653–1668, https://doi.org/10.5194/tc-18-1653-2024, https://doi.org/10.5194/tc-18-1653-2024, 2024
Short summary
Short summary
The specific surface of snow dictates key physical properties and continuously evolves in natural snowpacks. This is referred to as metamorphism. This work develops a rigorous physical model for this evolution, which is able to reproduce X-ray tomography measurements without using unphysical tuning parameters. Our results emphasize that snow crystal growth at the micrometer scale ultimately controls the pace of metamorphism.
Kavitha Sundu, Johannes Freitag, Kévin Fourteau, and Henning Löwe
The Cryosphere, 18, 1579–1596, https://doi.org/10.5194/tc-18-1579-2024, https://doi.org/10.5194/tc-18-1579-2024, 2024
Short summary
Short summary
Ice crystals often show a rod-like, vertical orientation in snow and firn; they are said to be anisotropic. The stiffness in the vertical direction therefore differs from the horizontal, which, for example, impacts the propagation of seismic waves. To quantify this anisotropy, we conducted finite-element simulations of 391 snow, firn, and ice core microstructures obtained from X-ray tomography. We then derived a parameterization that may be employed for advanced seismic studies in polar regions.
Amy R. Macfarlane, Henning Löwe, Lucille Gimenes, David N. Wagner, Ruzica Dadic, Rafael Ottersberg, Stefan Hämmerle, and Martin Schneebeli
The Cryosphere, 17, 5417–5434, https://doi.org/10.5194/tc-17-5417-2023, https://doi.org/10.5194/tc-17-5417-2023, 2023
Short summary
Short summary
Snow acts as an insulating blanket on Arctic sea ice, keeping the underlying ice "warm", relative to the atmosphere. Knowing the snow's thermal conductivity is essential for understanding winter ice growth. During the MOSAiC expedition, we measured the thermal conductivity of snow. We found spatial and vertical variability to overpower any temporal variability or dependency on underlying ice type and the thermal resistance to be directly influenced by snow height.
Julien Brondex, Kévin Fourteau, Marie Dumont, Pascal Hagenmuller, Neige Calonne, François Tuzet, and Henning Löwe
Geosci. Model Dev., 16, 7075–7106, https://doi.org/10.5194/gmd-16-7075-2023, https://doi.org/10.5194/gmd-16-7075-2023, 2023
Short summary
Short summary
Vapor diffusion is one of the main processes governing snowpack evolution, and it must be accounted for in models. Recent attempts to represent vapor diffusion in numerical models have faced several difficulties regarding computational cost and mass and energy conservation. Here, we develop our own finite-element software to explore numerical approaches and enable us to overcome these difficulties. We illustrate the capability of these approaches on established numerical benchmarks.
Sebastian Hellmann, Melchior Grab, Cedric Patzer, Andreas Bauder, and Hansruedi Maurer
Solid Earth, 14, 805–821, https://doi.org/10.5194/se-14-805-2023, https://doi.org/10.5194/se-14-805-2023, 2023
Short summary
Short summary
Acoustic waves are suitable to analyse the physical properties of the subsurface. For this purpose, boreholes are quite useful to deploy a source and receivers in the target area to get a comprehensive high-resolution dataset. However, when conducting such experiments in a subsurface such as glaciers that continuously move, the boreholes get deformed. In our study, we therefore developed a method that allows an analysis of the ice while considering deformations.
Nicolas Stoll, Julien Westhoff, Pascal Bohleber, Anders Svensson, Dorthe Dahl-Jensen, Carlo Barbante, and Ilka Weikusat
The Cryosphere, 17, 2021–2043, https://doi.org/10.5194/tc-17-2021-2023, https://doi.org/10.5194/tc-17-2021-2023, 2023
Short summary
Short summary
Impurities in polar ice play a role regarding its climate signal and internal deformation. We bridge different scales using different methods to investigate ice from the Last Glacial Period derived from the EGRIP ice core in Greenland. We characterise different types of cloudy bands, i.e. frequently occurring milky layers in the ice, and analyse their chemistry with Raman spectroscopy and 2D imaging. We derive new insights into impurity localisation and deposition conditions.
Ole Zeising, Tamara Annina Gerber, Olaf Eisen, M. Reza Ershadi, Nicolas Stoll, Ilka Weikusat, and Angelika Humbert
The Cryosphere, 17, 1097–1105, https://doi.org/10.5194/tc-17-1097-2023, https://doi.org/10.5194/tc-17-1097-2023, 2023
Short summary
Short summary
The flow of glaciers and ice streams is influenced by crystal fabric orientation. Besides sparse ice cores, these can be investigated by radar measurements. Here, we present an improved method which allows us to infer the horizontal fabric asymmetry using polarimetric phase-sensitive radar data. A validation of the method on a deep ice core from the Greenland Ice Sheet shows an excellent agreement, which is a large improvement over previously used methods.
Ghislain Picard, Henning Löwe, and Christian Mätzler
The Cryosphere, 16, 3861–3866, https://doi.org/10.5194/tc-16-3861-2022, https://doi.org/10.5194/tc-16-3861-2022, 2022
Short summary
Short summary
Microwave satellite observations used to monitor the cryosphere require radiative transfer models for their interpretation. These models represent how microwaves are scattered by snow and ice. However no existing theory is suitable for all types of snow and ice found on Earth. We adapted a recently published generic scattering theory to snow and show how it may improve the representation of snows with intermediate densities (~500 kg/m3) and/or with coarse grains at high microwave frequencies.
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
Short summary
Short summary
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.
Lea Geibel, Matthias Huss, Claudia Kurzböck, Elias Hodel, Andreas Bauder, and Daniel Farinotti
Earth Syst. Sci. Data, 14, 3293–3312, https://doi.org/10.5194/essd-14-3293-2022, https://doi.org/10.5194/essd-14-3293-2022, 2022
Short summary
Short summary
Glacier monitoring in Switzerland started in the 19th century, providing exceptional data series documenting snow accumulation and ice melt. Raw point observations of surface mass balance have, however, never been systematically compiled so far, including complete metadata. Here, we present an extensive dataset with more than 60 000 point observations of surface mass balance covering 60 Swiss glaciers and almost 140 years, promoting a better understanding of the drivers of recent glacier change.
Maria-Gema Llorens, Albert Griera, Paul D. Bons, Ilka Weikusat, David J. Prior, Enrique Gomez-Rivas, Tamara de Riese, Ivone Jimenez-Munt, Daniel García-Castellanos, and Ricardo A. Lebensohn
The Cryosphere, 16, 2009–2024, https://doi.org/10.5194/tc-16-2009-2022, https://doi.org/10.5194/tc-16-2009-2022, 2022
Short summary
Short summary
Polar ice is formed by ice crystals, which form fabrics that are utilised to interpret how ice sheets flow. It is unclear whether fabrics result from the current flow regime or if they are inherited. To understand the extent to which ice crystals can be reoriented when ice flow conditions change, we simulate and evaluate multi-stage ice flow scenarios according to natural cases. We find that second deformation regimes normally overprint inherited fabrics, with a range of transitional fabrics.
Julien Westhoff, Giulia Sinnl, Anders Svensson, Johannes Freitag, Helle Astrid Kjær, Paul Vallelonga, Bo Vinther, Sepp Kipfstuhl, Dorthe Dahl-Jensen, and Ilka Weikusat
Clim. Past, 18, 1011–1034, https://doi.org/10.5194/cp-18-1011-2022, https://doi.org/10.5194/cp-18-1011-2022, 2022
Short summary
Short summary
We present a melt event record from an ice core from central Greenland, which covers the past 10 000 years. Our record displays warm summer events, which can be used to enhance our understanding of the past climate. We compare our data to anomalies in tree ring width, which also represents summer temperatures, and find a good correlation. Furthermore, we investigate an outstandingly warm event in the year 986 AD or 991 AD, which has not been analyzed before.
Konstantin Schürholt, Julia Kowalski, and Henning Löwe
The Cryosphere, 16, 903–923, https://doi.org/10.5194/tc-16-903-2022, https://doi.org/10.5194/tc-16-903-2022, 2022
Short summary
Short summary
This companion paper deals with numerical particularities of partial differential equations underlying 1D snow models. In this first part we neglect mechanical settling and demonstrate that the nonlinear coupling between diffusive transport (heat and vapor), phase changes and ice mass conservation contains a wave instability that may be relevant for weak layer formation. Numerical requirements are discussed in view of the underlying homogenization scheme.
Nicolas Stoll, Maria Hörhold, Tobias Erhardt, Jan Eichler, Camilla Jensen, and Ilka Weikusat
The Cryosphere, 16, 667–688, https://doi.org/10.5194/tc-16-667-2022, https://doi.org/10.5194/tc-16-667-2022, 2022
Short summary
Short summary
We mapped and analysed solid inclusion in the upper 1340 m of the EGRIP ice core with Raman spectroscopy and microstructure mapping, based on bulk dust content derived via continuous flow analysis. We observe a large variety in mineralogy throughout the core and samples. The main minerals are sulfates, especially gypsum, and terrestrial dust minerals, such as quartz, mica, and feldspar. A change in mineralogy occurs around 900 m depth indicating a climate-related imprint.
Steven Franke, Daniela Jansen, Tobias Binder, John D. Paden, Nils Dörr, Tamara A. Gerber, Heinrich Miller, Dorthe Dahl-Jensen, Veit Helm, Daniel Steinhage, Ilka Weikusat, Frank Wilhelms, and Olaf Eisen
Earth Syst. Sci. Data, 14, 763–779, https://doi.org/10.5194/essd-14-763-2022, https://doi.org/10.5194/essd-14-763-2022, 2022
Short summary
Short summary
The Northeast Greenland Ice Stream (NEGIS) is the largest ice stream in Greenland. In order to better understand the past and future dynamics of the NEGIS, we present a high-resolution airborne radar data set (EGRIP-NOR-2018) for the onset region of the NEGIS. The survey area is centered at the location of the drill site of the East Greenland Ice-Core Project (EastGRIP), and radar profiles cover both shear margins and are aligned parallel to several flow lines.
Xiaodong Ma, Marian Hertrich, Florian Amann, Kai Bröker, Nima Gholizadeh Doonechaly, Valentin Gischig, Rebecca Hochreutener, Philipp Kästli, Hannes Krietsch, Michèle Marti, Barbara Nägeli, Morteza Nejati, Anne Obermann, Katrin Plenkers, Antonio P. Rinaldi, Alexis Shakas, Linus Villiger, Quinn Wenning, Alba Zappone, Falko Bethmann, Raymi Castilla, Francisco Seberto, Peter Meier, Thomas Driesner, Simon Loew, Hansruedi Maurer, Martin O. Saar, Stefan Wiemer, and Domenico Giardini
Solid Earth, 13, 301–322, https://doi.org/10.5194/se-13-301-2022, https://doi.org/10.5194/se-13-301-2022, 2022
Short summary
Short summary
Questions on issues such as anthropogenic earthquakes and deep geothermal energy developments require a better understanding of the fractured rock. Experiments conducted at reduced scales but with higher-resolution observations can shed some light. To this end, the BedrettoLab was recently established in an existing tunnel in Ticino, Switzerland, with preliminary efforts to characterize realistic rock mass behavior at the hectometer scale.
Nicolas Stoll, Jan Eichler, Maria Hörhold, Tobias Erhardt, Camilla Jensen, and Ilka Weikusat
The Cryosphere, 15, 5717–5737, https://doi.org/10.5194/tc-15-5717-2021, https://doi.org/10.5194/tc-15-5717-2021, 2021
Short summary
Short summary
We did a systematic analysis of the location of inclusions in the EGRIP ice core, the first ice core from an ice stream. We combine this with crystal orientation and grain size data, enabling the first overview about the microstructure of this unique ice core. Micro-inclusions show a strong spatial variability and patterns (clusters or horizontal layers); roughly one-third is located at grain boundaries. More holistic approaches are needed to understand deformation processes in the ice better.
Anna Simson, Henning Löwe, and Julia Kowalski
The Cryosphere, 15, 5423–5445, https://doi.org/10.5194/tc-15-5423-2021, https://doi.org/10.5194/tc-15-5423-2021, 2021
Short summary
Short summary
This companion paper deals with numerical particularities of partial differential equations underlying one-dimensional snow models. In this second part we include mechanical settling and develop a new hybrid (Eulerian–Lagrangian) method for solving the advection-dominated ice mass conservation on a moving mesh alongside Eulerian diffusion (heat and vapor) and phase changes. The scheme facilitates a modular and extendable solver strategy while retaining controls on numerical accuracy.
Gregory Church, Andreas Bauder, Melchior Grab, and Hansruedi Maurer
The Cryosphere, 15, 3975–3988, https://doi.org/10.5194/tc-15-3975-2021, https://doi.org/10.5194/tc-15-3975-2021, 2021
Short summary
Short summary
In this field study, we acquired a 3D radar survey over an active drainage network that transported meltwater through a Swiss glacier. We successfully imaged both englacial and subglacial pathways and were able to confirm long-standing glacier hydrology theory regarding meltwater pathways. The direction of these meltwater pathways directly impacts the glacier's velocity, and therefore more insightful field observations are needed in order to improve our understanding of this complex system.
Peter-Lasse Giertzuch, Joseph Doetsch, Alexis Shakas, Mohammadreza Jalali, Bernard Brixel, and Hansruedi Maurer
Solid Earth, 12, 1497–1513, https://doi.org/10.5194/se-12-1497-2021, https://doi.org/10.5194/se-12-1497-2021, 2021
Short summary
Short summary
Two time-lapse borehole ground penetrating radar (GPR) surveys were conducted during saline tracer experiments in weakly fractured crystalline rock with sub-millimeter fractures apertures, targeting electrical conductivity changes. The combination of time-lapse reflection and transmission GPR surveys from different boreholes allowed monitoring the tracer flow and reconstructing the flow path and its temporal evolution in 3D and provided a realistic visualization of the hydrological processes.
Paul D. Bons, Tamara de Riese, Steven Franke, Maria-Gema Llorens, Till Sachau, Nicolas Stoll, Ilka Weikusat, Julien Westhoff, and Yu Zhang
The Cryosphere, 15, 2251–2254, https://doi.org/10.5194/tc-15-2251-2021, https://doi.org/10.5194/tc-15-2251-2021, 2021
Short summary
Short summary
The modelling of Smith-Johnson et al. (The Cryosphere, 14, 841–854, 2020) suggests that a very large heat flux of more than 10 times the usual geothermal heat flux is required to have initiated or to control the huge Northeast Greenland Ice Stream. Our comparison with known hotspots, such as Iceland and Yellowstone, shows that such an exceptional heat flux would be unique in the world and is incompatible with known geological processes that can raise the heat flux.
Sebastian Hellmann, Johanna Kerch, Ilka Weikusat, Andreas Bauder, Melchior Grab, Guillaume Jouvet, Margit Schwikowski, and Hansruedi Maurer
The Cryosphere, 15, 677–694, https://doi.org/10.5194/tc-15-677-2021, https://doi.org/10.5194/tc-15-677-2021, 2021
Short summary
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.
Alba Zappone, Antonio Pio Rinaldi, Melchior Grab, Quinn C. Wenning, Clément Roques, Claudio Madonna, Anne C. Obermann, Stefano M. Bernasconi, Matthias S. Brennwald, Rolf Kipfer, Florian Soom, Paul Cook, Yves Guglielmi, Christophe Nussbaum, Domenico Giardini, Marco Mazzotti, and Stefan Wiemer
Solid Earth, 12, 319–343, https://doi.org/10.5194/se-12-319-2021, https://doi.org/10.5194/se-12-319-2021, 2021
Short summary
Short summary
The success of the geological storage of carbon dioxide is linked to the availability at depth of a capable reservoir and an impermeable caprock. The sealing capacity of the caprock is a key parameter for long-term CO2 containment. Faults crosscutting the caprock might represent preferential pathways for CO2 to escape. A decameter-scale experiment on injection in a fault, monitored by an integrated network of multiparamerter sensors, sheds light on the mobility of fluids within the fault.
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
The Cryosphere, 15, 485–500, https://doi.org/10.5194/tc-15-485-2021, https://doi.org/10.5194/tc-15-485-2021, 2021
Short summary
Short summary
The dynamic mass loss of tidewater glaciers is strongly linked to glacier calving. We study calving mechanisms under a thinning regime, based on 5 years of field and remote-sensing data of Bowdoin Glacier. Our data suggest that Bowdoin Glacier ungrounded recently, and its calving behaviour changed from calving due to surface crevasses to buoyancy-induced calving resulting from basal crevasses. This change may be a precursor to glacier retreat.
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
Short summary
Short summary
We show that plutonium is an effective tracer to identify ice originating from the early 1960s at the surface of a mountain glacier after a long time within the ice flow, giving unique information on the long-term former ice motion. Combined with ice flow modelling, the dating can be extended to the entire glacier, and we show that an airplane which crash-landed on the Gauligletscher in 1946 will likely soon be released from the ice close to the place where pieces have emerged in recent years.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Neige Calonne, Bettina Richter, Henning Löwe, Cecilia Cetti, Judith ter Schure, Alec Van Herwijnen, Charles Fierz, Matthias Jaggi, and Martin Schneebeli
The Cryosphere, 14, 1829–1848, https://doi.org/10.5194/tc-14-1829-2020, https://doi.org/10.5194/tc-14-1829-2020, 2020
Short summary
Short summary
During winter 2015–2016, the standard program to monitor the structure and stability of the snowpack at Weissflujoch, Swiss Alps, was complemented by additional measurements to compare between various traditional and newly developed techniques. Snow micro-penetrometer measurements allowed monitoring of the evolution of the snowpack's internal structure at a daily resolution throughout the winter. We show the potential of such high-resolution data for detailed evaluations of snowpack models.
Silvan Leinss, Henning Löwe, Martin Proksch, and Anna Kontu
The Cryosphere, 14, 51–75, https://doi.org/10.5194/tc-14-51-2020, https://doi.org/10.5194/tc-14-51-2020, 2020
Short summary
Short summary
The anisotropy of the snow microstructure, given by horizontally aligned ice crystals and vertically interlinked crystal chains, is a key quantity to understand mechanical, dielectric, and thermodynamical properties of snow. We present a model which describes the temporal evolution of the anisotropy. The model is driven by snow temperature, temperature gradient, and the strain rate. The model is calibrated by polarimetric radar data (CPD) and validated by computer tomographic 3-D snow images.
Kévin Fourteau, Patricia Martinerie, Xavier Faïn, Christoph F. Schaller, Rebecca J. Tuckwell, Henning Löwe, Laurent Arnaud, Olivier Magand, Elizabeth R. Thomas, Johannes Freitag, Robert Mulvaney, Martin Schneebeli, and Vladimir Ya. Lipenkov
The Cryosphere, 13, 3383–3403, https://doi.org/10.5194/tc-13-3383-2019, https://doi.org/10.5194/tc-13-3383-2019, 2019
Short summary
Short summary
Understanding gas trapping in polar ice is essential to study the relationship between greenhouse gases and past climates. New data of bubble closure, used in a simple gas-trapping model, show inconsistency with the final air content in ice. This suggests gas trapping is not fully understood. We also use a combination of high-resolution measurements to investigate the effect of polar snow stratification on gas trapping and find that all strata have similar pores, but that some close in advance.
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
Short summary
Short summary
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.
Isabelle Gouttevin, Moritz Langer, Henning Löwe, Julia Boike, Martin Proksch, and Martin Schneebeli
The Cryosphere, 12, 3693–3717, https://doi.org/10.5194/tc-12-3693-2018, https://doi.org/10.5194/tc-12-3693-2018, 2018
Short summary
Short summary
Snow insulates the ground from the cold air in the Arctic winter, majorly affecting permafrost. This insulation depends on snow characteristics and is poorly quantified. Here, we characterize it at a carbon-rich permafrost site, using a recent technique that retrieves the 3-D structure of snow and its thermal properties. We adapt a snowpack model enabling the simulation of this insulation over a whole winter. We estimate that local snow variations induce up to a 6 °C spread in soil temperatures.
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
Short summary
Short summary
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.
Ghislain Picard, Melody Sandells, and Henning Löwe
Geosci. Model Dev., 11, 2763–2788, https://doi.org/10.5194/gmd-11-2763-2018, https://doi.org/10.5194/gmd-11-2763-2018, 2018
Short summary
Short summary
The Snow Microwave Radiative Transfer (SMRT) is a novel model developed to calculate how microwaves are scattered and emitted by snow. The model is built from separate, interconnecting modules to make it easy to compare different aspects of the theory. SMRT is the first model to allow a choice of how to represent the microstructure of the snow, which is extremely important, and has been used to unite multiple previous studies. This model will ultimately be used to observe snow from space.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Quirine Krol and Henning Löwe
The Cryosphere, 10, 2847–2863, https://doi.org/10.5194/tc-10-2847-2016, https://doi.org/10.5194/tc-10-2847-2016, 2016
Short summary
Short summary
Optical and microwave modelling of snow involve different metrics of "grain size" and existing, empirical relations between them are subject to considerable scatter. We introduce two objectively defined metrics of grain shape, derived from micro-computed tomography images, that lead to improved statistical models between the different grain metrics. Our results allow to assess the relevance of grain shape in both fields on common grounds.
Silvan Leinss, Henning Löwe, Martin Proksch, Juha Lemmetyinen, Andreas Wiesmann, and Irena Hajnsek
The Cryosphere, 10, 1771–1797, https://doi.org/10.5194/tc-10-1771-2016, https://doi.org/10.5194/tc-10-1771-2016, 2016
Short summary
Short summary
Four years of anisotropy measurements of seasonal snow are presented in the paper. The anisotropy was measured every 4 h with a ground-based polarimetric radar. An electromagnetic model has been developed to measured the anisotropy with radar instruments from ground and from space. The anisotropic permittivity was derived with Maxwell–Garnett-type mixing formulas which are shown to be equivalent to series expansions of the permittivity tensor based on spatial correlation function of snow.
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
Short summary
Short summary
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.
H. Löwe and G. Picard
The Cryosphere, 9, 2101–2117, https://doi.org/10.5194/tc-9-2101-2015, https://doi.org/10.5194/tc-9-2101-2015, 2015
Short summary
Short summary
The paper establishes a theoretical link between two widely used microwave models for snow. The scattering formulations from both models are unified by reformulating their microstructure models in a common framework. The results show that the scattering formulations can be considered equivalent, if exactly the same microstructure model is used. The paper also provides a method to measure a hitherto unknown input parameter for the microwave models from tomography images of snow.
M. Proksch, C. Mätzler, A. Wiesmann, J. Lemmetyinen, M. Schwank, H. Löwe, and M. Schneebeli
Geosci. Model Dev., 8, 2611–2626, https://doi.org/10.5194/gmd-8-2611-2015, https://doi.org/10.5194/gmd-8-2611-2015, 2015
Short summary
Short summary
The measurement of snow properties on global scale relies on microwave remote sensing data. The interpretation of the data is however challenging. Here we introduce MEMLS3&a, an extension of the snow emission model MEMLS, to include a backscatter model for active microwave remote sensing. In MEMLS3&a, snow input parameters can be derived by objective measurement methods, which avoids fitting the scattering efficiency of snow. The model is validated with combined active and passive measurements.
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
Short summary
Short summary
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.
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
S. Schleef, H. Löwe, and M. Schneebeli
The Cryosphere, 8, 1825–1838, https://doi.org/10.5194/tc-8-1825-2014, https://doi.org/10.5194/tc-8-1825-2014, 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
H. Löwe, F. Riche, and M. Schneebeli
The Cryosphere, 7, 1473–1480, https://doi.org/10.5194/tc-7-1473-2013, https://doi.org/10.5194/tc-7-1473-2013, 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: Ice Cores
Reconstruction of mass balance and firn stratigraphy during the 1996–2011 warm period at high-altitude on Mt. Ortles, Eastern Alps: a comparison of modelled and ice core results
Temporal markers in a temperate ice core: insights from 3H and 137Cs profiles from the Adamello Glacier
Review article: Melt-affected ice cores for polar research in a warming world
Impact of subsurface crevassing on the depth–age relationship of high-Alpine ice cores extracted at Col du Dôme between 1994 and 2012
Fifty years of firn evolution on Grigoriev ice cap, Tien Shan, Kyrgyzstan
Climate change is rapidly deteriorating the climatic signal in Svalbard glaciers
Identifying atmospheric processes favouring the formation of bubble-free layers in the Law Dome ice core, East Antarctica
Early Holocene ice on the Begguya plateau (Mt. Hunter, Alaska) revealed by ice core 14C age constraints
Chronostratigraphy of the Larsen blue-ice area in northern Victoria Land, East Antarctica, and its implications for paleoclimate
A quantitative method of resolving annual precipitation for the past millennia from Tibetan ice cores
Brief communication: New evidence further constraining Tibetan ice core chronologies to the Holocene
Giant dust particles at Nevado Illimani: a proxy of summertime deep convection over the Bolivian Altiplano
Physical properties of shallow ice cores from Antarctic and sub-Antarctic islands
Stable water isotopes and accumulation rates in the Union Glacier region, Ellsworth Mountains, West Antarctica, over the last 35 years
Apparent discrepancy of Tibetan ice core δ18O records may be attributed to misinterpretation of chronology
Age ranges of the Tibetan ice cores with emphasis on the Chongce ice cores, western Kunlun Mountains
Luca Carturan, Alexander C. Ihle, Federico Cazorzi, Tiziana Lazzarina Zendrini, Fabrizio De Blasi, Giancarlo Dalla Fontana, Giuliano Dreossi, Daniela Festi, Bryan Mark, Klaus Dieter Oeggl, Roberto Seppi, Barbara Stenni, and Paolo Gabrielli
EGUsphere, https://doi.org/10.5194/egusphere-2025-729, https://doi.org/10.5194/egusphere-2025-729, 2025
Short summary
Short summary
Paleoclimatic glacial archives in low-latitude mountains are increasingly affected by melt, causing heavy percolation and removing snow and firn accumulated across months, seasons or even years. Here we present a proxy system model that explicitly accounts for melt in ice and firn cores. Compared to traditional annual layer counting, the model significantly improved the interpretation and annual dating of the Mt. Ortles firn core, in the Italian Alps, that includes the very warm summer 2003.
Elena Di Stefano, Giovanni Baccolo, Massimiliano Clemenza, Barbara Delmonte, Deborah Fiorini, Roberto Garzonio, Margit Schwikowski, and Valter Maggi
The Cryosphere, 18, 2865–2874, https://doi.org/10.5194/tc-18-2865-2024, https://doi.org/10.5194/tc-18-2865-2024, 2024
Short summary
Short summary
Rising temperatures are impacting the reliability of glaciers as environmental archives. This study reports how meltwater percolation affects the distribution of tritium and cesium, which are commonly used as temporal markers in dating ice cores, in a temperate glacier. Our findings challenge the established application of radionuclides for dating mountain ice cores and indicate tritium as the best choice.
Dorothea Elisabeth Moser, Elizabeth R. Thomas, Christoph Nehrbass-Ahles, Anja Eichler, and Eric Wolff
The Cryosphere, 18, 2691–2718, https://doi.org/10.5194/tc-18-2691-2024, https://doi.org/10.5194/tc-18-2691-2024, 2024
Short summary
Short summary
Increasing temperatures worldwide lead to more melting of glaciers and ice caps, even in the polar regions. This is why ice-core scientists need to prepare to analyse records affected by melting and refreezing. In this paper, we present a summary of how near-surface melt forms, what structural imprints it leaves in snow, how various signatures used for ice-core climate reconstruction are altered, and how we can still extract valuable insights from melt-affected ice cores.
Susanne Preunkert, Pascal Bohleber, Michel Legrand, Adrien Gilbert, Tobias Erhardt, Roland Purtschert, Lars Zipf, Astrid Waldner, Joseph R. McConnell, and Hubertus Fischer
The Cryosphere, 18, 2177–2194, https://doi.org/10.5194/tc-18-2177-2024, https://doi.org/10.5194/tc-18-2177-2024, 2024
Short summary
Short summary
Ice cores from high-elevation Alpine glaciers are an important tool to reconstruct the past atmosphere. However, since crevasses are common at these glacier sites, rigorous investigations of glaciological conditions upstream of drill sites are needed before interpreting such ice cores. On the basis of three ice cores extracted at Col du Dôme (4250 m a.s.l; French Alps), an overall picture of a dynamic crevasse formation is drawn, which disturbs the depth–age relation of two of the three cores.
Horst Machguth, Anja Eichler, Margit Schwikowski, Sabina Brütsch, Enrico Mattea, Stanislav Kutuzov, Martin Heule, Ryskul Usubaliev, Sultan Belekov, Vladimir N. Mikhalenko, Martin Hoelzle, and Marlene Kronenberg
The Cryosphere, 18, 1633–1646, https://doi.org/10.5194/tc-18-1633-2024, https://doi.org/10.5194/tc-18-1633-2024, 2024
Short summary
Short summary
In 2018 we drilled an 18 m ice core on the summit of Grigoriev ice cap, located in the Tien Shan mountains of Kyrgyzstan. The core analysis reveals strong melting since the early 2000s. Regardless of this, we find that the structure and temperature of the ice have changed little since the 1980s. The probable cause of this apparent stability is (i) an increase in snowfall and (ii) the fact that meltwater nowadays leaves the glacier and thereby removes so-called latent heat.
Andrea Spolaor, Federico Scoto, Catherine Larose, Elena Barbaro, Francois Burgay, Mats P. Bjorkman, David Cappelletti, Federico Dallo, Fabrizio de Blasi, Dmitry Divine, Giuliano Dreossi, Jacopo Gabrieli, Elisabeth Isaksson, Jack Kohler, Tonu Martma, Louise S. Schmidt, Thomas V. Schuler, Barbara Stenni, Clara Turetta, Bartłomiej Luks, Mathieu Casado, and Jean-Charles Gallet
The Cryosphere, 18, 307–320, https://doi.org/10.5194/tc-18-307-2024, https://doi.org/10.5194/tc-18-307-2024, 2024
Short summary
Short summary
We evaluate the impact of the increased snowmelt on the preservation of the oxygen isotope (δ18O) signal in firn records recovered from the top of the Holtedahlfonna ice field located in the Svalbard archipelago. Thanks to a multidisciplinary approach we demonstrate a progressive deterioration of the isotope signal in the firn core. We link the degradation of the δ18O signal to the increased occurrence and intensity of melt events associated with the rapid warming occurring in the archipelago.
Lingwei Zhang, Tessa R. Vance, Alexander D. Fraser, Lenneke M. Jong, Sarah S. Thompson, Alison S. Criscitiello, and Nerilie J. Abram
The Cryosphere, 17, 5155–5173, https://doi.org/10.5194/tc-17-5155-2023, https://doi.org/10.5194/tc-17-5155-2023, 2023
Short summary
Short summary
Physical features in ice cores provide unique records of past variability. We identified 1–2 mm ice layers without bubbles in surface ice cores from Law Dome, East Antarctica, occurring on average five times per year. The origin of these bubble-free layers is unknown. In this study, we investigate whether they have the potential to record past atmospheric processes and circulation. We find that the bubble-free layers are linked to accumulation hiatus events and meridional moisture transport.
Ling Fang, Theo M. Jenk, Dominic Winski, Karl Kreutz, Hanna L. Brooks, Emma Erwin, Erich Osterberg, Seth Campbell, Cameron Wake, and Margit Schwikowski
The Cryosphere, 17, 4007–4020, https://doi.org/10.5194/tc-17-4007-2023, https://doi.org/10.5194/tc-17-4007-2023, 2023
Short summary
Short summary
Understanding the behavior of ocean–atmosphere teleconnections in the North Pacific during warm intervals can aid in predicting future warming scenarios. However, majority ice core records from Alaska–Yukon region only provide data for the last few centuries. This study introduces a continuous chronology for Denali ice core from Begguya, Alaska, using multiple dating methods. The early-Holocene-origin Denali ice core will facilitate future investigations of hydroclimate in the North Pacific.
Giyoon Lee, Jinho Ahn, Hyeontae Ju, Florian Ritterbusch, Ikumi Oyabu, Christo Buizert, Songyi Kim, Jangil Moon, Sambit Ghosh, Kenji Kawamura, Zheng-Tian Lu, Sangbum Hong, Chang Hee Han, Soon Do Hur, Wei Jiang, and Guo-Min Yang
The Cryosphere, 16, 2301–2324, https://doi.org/10.5194/tc-16-2301-2022, https://doi.org/10.5194/tc-16-2301-2022, 2022
Short summary
Short summary
Blue-ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the area hinders constraining the age. We applied state-of-the-art techniques and found that the ages cover the last deglaciation period. Our study demonstrates that the BIA in northern Victoria Land may help reconstruct the past climate during the termination of the last glacial period.
Wangbin Zhang, Shugui Hou, Shuang-Ye Wu, Hongxi Pang, Sharon B. Sneed, Elena V. Korotkikh, Paul A. Mayewski, Theo M. Jenk, and Margit Schwikowski
The Cryosphere, 16, 1997–2008, https://doi.org/10.5194/tc-16-1997-2022, https://doi.org/10.5194/tc-16-1997-2022, 2022
Short summary
Short summary
This study proposes a quantitative method to reconstruct annual precipitation records at the millennial timescale from the Tibetan ice cores through combining annual layer identification based on LA-ICP-MS measurement with an ice flow model. The reliability of this method is assessed by comparing our results with other reconstructed and modeled precipitation series for the Tibetan Plateau. The assessment shows that the method has a promising performance.
Shugui Hou, Wangbin Zhang, Ling Fang, Theo M. Jenk, Shuangye Wu, Hongxi Pang, and Margit Schwikowski
The Cryosphere, 15, 2109–2114, https://doi.org/10.5194/tc-15-2109-2021, https://doi.org/10.5194/tc-15-2109-2021, 2021
Short summary
Short summary
We present ages for two new ice cores reaching bedrock, from the Zangser Kangri (ZK) glacier in the northwestern Tibetan Plateau and the Shulenanshan (SLNS) glacier in the western Qilian Mountains. We estimated bottom ages of 8.90±0.57/0.56 ka and 7.46±1.46/1.79 ka for the ZK and SLNS ice core respectively, constraining the time range accessible by Tibetan ice cores to the Holocene.
Filipe G. L. Lindau, Jefferson C. Simões, Barbara Delmonte, Patrick Ginot, Giovanni Baccolo, Chiara I. Paleari, Elena Di Stefano, Elena Korotkikh, Douglas S. Introne, Valter Maggi, Eduardo Garzanti, and Sergio Andò
The Cryosphere, 15, 1383–1397, https://doi.org/10.5194/tc-15-1383-2021, https://doi.org/10.5194/tc-15-1383-2021, 2021
Short summary
Short summary
Information about the past climate variability in tropical South America is stored in the snow layers of the tropical Andean glaciers. Here we show evidence that the presence of very large aeolian mineral dust particles at Nevado Illimani (Bolivia) is strictly controlled by the occurrence of summer storms in the Bolivian Altiplano. Therefore, based on the snow dust content and its composition of stable water isotopes, we propose a new proxy for information on previous summer storms.
Elizabeth Ruth Thomas, Guisella Gacitúa, Joel B. Pedro, Amy Constance Faith King, Bradley Markle, Mariusz Potocki, and Dorothea Elisabeth Moser
The Cryosphere, 15, 1173–1186, https://doi.org/10.5194/tc-15-1173-2021, https://doi.org/10.5194/tc-15-1173-2021, 2021
Short summary
Short summary
Here we present the first-ever radar and ice core data from the sub-Antarctic islands of Bouvet Island, Peter I Island, and Young Island. These islands have the potential to record past climate in one of the most data-sparse regions on earth. Despite their northerly location, surface melting is generally low, and the upper layer of the ice at most sites is undisturbed. We estimate that a 100 m ice core drilled on these islands could capture climate over the past 100–200 years.
Kirstin Hoffmann, Francisco Fernandoy, Hanno Meyer, Elizabeth R. Thomas, Marcelo Aliaga, Dieter Tetzner, Johannes Freitag, Thomas Opel, Jorge Arigony-Neto, Christian Florian Göbel, Ricardo Jaña, Delia Rodríguez Oroz, Rebecca Tuckwell, Emily Ludlow, Joseph R. McConnell, and Christoph Schneider
The Cryosphere, 14, 881–904, https://doi.org/10.5194/tc-14-881-2020, https://doi.org/10.5194/tc-14-881-2020, 2020
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Cited articles
Aki, K. and Richards, P. G.: Quantitative Seismology,
Quantitative Seismology, edited by: Aki, K. and Richards, P. G..
University Science Books, 2nd Edn., ISBN 0-935702-96-2, 704pp, 2002. a
Alley, R. B.: Fabrics in Polar Ice Sheets: Development and Prediction, Science,
240, 493–495, 1988. a
Alley, R. B.: Flow-Law Hypotheses for Ice-Sheet Modeling, J.
Glaciol., 38, 245–256, 1992. a
Anandakrishnan, S., Fltzpatrick, J. J., Alley, R. B., Gow, A. J., and Meese,
D. A.: Shear-Wave Detection of Asymmetric c-Axis Fabrics in the GISP2 Ice
Core, Greenland, J. Glaciol., 40, 491–496,
https://doi.org/10.3189/S0022143000012363, 1994. a
Azuma, N.: A Flow Law for Anisotropic Ice and Its Application to Ice Sheets,
Earth Planet Sc. Lett., 128, 601–614,
https://doi.org/10.1016/0012-821X(94)90173-2, 1994. a
Azuma, N. and Higashi, A.: Mechanical Properties of Dye 3 Greenland
Deep Ice Cores, Ann. Glaciol., 5, 1–8, 1984. a
Bennett, H. F.: An Investigation into Velocity Anisotropy through Measurements
of Ultrasonica Wave Velocities in Snow and Ice Cores from Greenland and
Antarctica(Investigation into Velocity Anisotropy through
Measurements of Ultrasonic Wave Velocities in Snow and Ice Cores from
Greenland and Antarctica), PhD Thesis, University of
Wisconsin-Madison, 1968. a
Bentley, C. R.: Seismic-Wave Velocities in Anisotropic Ice: A Comparison of
Measured and Calculated Values in and around the Deep Drill Hole at Byrd
Station, Antarctica, J. Geophys. Res., 77,
4406–4420, https://doi.org/10.1029/JB077i023p04406, 1972. a, b
Bentley, C. R.: Advances in Geophysical Exploration of Ice Sheets and Glaciers,
J. Glaciol., 15, 113–135, https://doi.org/10.3189/S0022143000034328, 1975. a
Binder, T., Garbe, C. S., Wagenbach, D., Freitag, J., and Kipfstuhl, S.:
Extraction and Parametrization of Grain Boundary Networks in Glacier Ice,
Using a Dedicated Method of Automatic Image Analysis, J. Microsc.,
250, 130–141, https://doi.org/10.1111/jmi.12029, 2013. a
Blankenship, D. D. and Bentley, C. R.: The Crystalline Fabric of Polar Ice
Sheets Inferred from Seismic Anisotropy, IAHS Publ., 170, 17–28, 1987. a
Brisbourne, A. M., Martín, C., Smith, A. M., Baird, A. F., Kendall, J. M.,
and Kingslake, J.: Constraining Recent Ice Flow History at Korff Ice
Rise, West Antarctica, Using Radar and Seismic Measurements of
Ice Fabric, J. Geophys. Res.-Earth, 124/1, 175–194,
https://doi.org/10.1029/2018JF004776, 2019. a
Budd, W. F. and Jacka, T. H.: A Review of Ice Rheology for Ice Sheet Modelling,
Cold Reg. Sci. Technol., 16, 107–144,
https://doi.org/10.1016/0165-232X(89)90014-1, 1989. a
Cuffey, K. M. and Paterson, W. S. B.: The Physics of Glaciers, 4th Edn., Elsevier,
Amsterdam, 2010. a
Diez, A. and Eisen, O.: Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties, The Cryosphere, 9, 367–384, https://doi.org/10.5194/tc-9-367-2015, 2015. a, b, c
Diez, A., Eisen, O., Weikusat, I., Eichler, J., Hofstede, C., Bohleber, P.,
Bohlen, T., and Polom, U.: Influence of Ice Crystal Anisotropy on Seismic
Velocity Analysis, Ann. Glaciol., 55, 97–106,
https://doi.org/10.3189/2014AoG67A002, 2014. a
Diez, A., Eisen, O., Hofstede, C., Lambrecht, A., Mayer, C., Miller, H., Steinhage, D., Binder, T., and Weikusat, I.: Seismic wave propagation in anisotropic ice – Part 2: Effects of crystal anisotropy in geophysical data, The Cryosphere, 9, 385–398, https://doi.org/10.5194/tc-9-385-2015, 2015. a, b
Drews, R., Eisen, O., Steinhage, D., Weikusat, I., Kipfstuhl, S., and Wilhelms,
F.: Potential Mechanisms for Anisotropy in Ice-Penetrating Radar Data,
J. Glaciol., 58, 613–624, https://doi.org/10.3189/2012JoG11J114, 2012. a
Eichler, J.: C-Axis Analysis of the NEEM Ice Core – An
Approach Based on Digital Image Processing, Diploma Thesis, Freie
Universität Berlin, 2013. a
Faria, S. H., Weikusat, I., and Azuma, N.: The Microstructure of Polar Ice.
Part II: State of the Art, J. Struct. Geol., 61, 21–49,
https://doi.org/10.1016/j.jsg.2013.11.003, 2014. a, b
Fourteau, K., Martinerie, P., Faïn, X., Schaller, C. F., Tuckwell, R. J., Löwe, H., Arnaud, L., Magand, O., Thomas, E. R., Freitag, J., Mulvaney, R., Schneebeli, M., and Lipenkov, V. Ya.: Multi-tracer study of gas trapping in an East Antarctic ice core, The Cryosphere, 13, 3383–3403, https://doi.org/10.5194/tc-13-3383-2019, 2019. a
Freitag, J., Wilhelms, F., and Kipfstuhl, S.: Microstructure-Dependent
Densification of Polar Firn Derived from X-Ray Microtomography, J.
Glaciol., 50, 243–250, https://doi.org/10.3189/172756504781830123, 2004. a
Gerling, B., Löwe, H., and van Herwijnen, A.: Measuring the Elastic
Modulus of Snow, Geophys. Res. Lett., 44, 11088–11096,
https://doi.org/10.1002/2017GL075110, 2017. a, b
Gillet-Chaulet, F., Gagliardini, O., Meyssonnier, J., Montagnat, M., and
Castelnau, O.: A User-Friendly Anisotropic Flow Law for Ice-Sheet Modeling,
J. Glaciol., 51, 3–14, https://doi.org/10.3189/172756505781829584, 2005. a
Graham, F. S., Morlighem, M., Warner, R. C., and Treverrow, A.: Implementing an empirical scalar constitutive relation for ice with flow-induced polycrystalline anisotropy in large-scale ice sheet models, The Cryosphere, 12, 1047–1067, https://doi.org/10.5194/tc-12-1047-2018, 2018. a
Gusmeroli, A., Pettit, E. C., Kennedy, J. H., and Ritz, C.: The Crystal Fabric
of Ice from Full-Waveform Borehole Sonic Logging: Borehole sonic logging in
ice sheets, J. Geophys. Res.-Earth, 117, F03021,
https://doi.org/10.1029/2012JF002343, 2012. a, b
Hagenmuller, P., Chambon, G., Lesaffre, B., Flin, F., and Naaim, M.:
Energy-Based Binary Segmentation of Snow Microtomographic Images, J.
Glaciol., 59, 859–873, https://doi.org/10.3189/2013JoG13J035, 2013. a
Hellmann, S., Kerch, J., Eichler, J., Jansen, D., Weikusat, I., Schwikowski,
M., Bauder, A., and Maurer, H.: Crystal C-Axes Measurements (Fabric
Analyser G50) of Ice Core Samples Collected from the Temperate Alpine
Ice Core Rhone_2017, PANGAEA, https://doi.org/10.1594/PANGAEA.888518, 2018a. a
Hellmann, S., Kerch, J., Eichler, J., Jansen, D., Weikusat, I., Schwikowski,
M., Bauder, A., and Maurer, H.: Large Area Scan Macroscope Images of Ice
Core Samples Collected from the Temperate Alpine Ice Core
Rhone_2017, PANGAEA, https://doi.org/10.1594/PANGAEA.888517, 2018b. a
Hellmann, S., Grab, M., Jaggi, M., Löwe, H., and Bauder, A.: Acoustic
Ultrasound Measurements on Ice Core Samples from Rhonegletscher, ETH
Zurich, https://doi.org/10.3929/ethz-b-000453859, 2020. a
Hill, R.: The Elastic Behaviour of a Crystalline Aggregate, Proc. Phys. Soc. A, 65, 349–354,
https://doi.org/10.1088/0370-1298/65/5/307, 1952. a
Hooke, R. L. and Hudleston, P. J.: Ice Fabrics in a Vertical Flow
Plane, Barnes Ice Cap, Canada, J. Glaciol., 25, 195–214,
https://doi.org/10.3189/S0022143000010443, 1980. a, b
Jordan, T. M., Schroeder, D. M., Castelletti, D., Li, J., and Dall, J.: A
Polarimetric Coherence Method to Determine Ice Crystal Orientation
Fabric From Radar Sounding: Application to the NEEM Ice Core
Region, IEEE T. Geosci. Remote, 57, 8641–8657,
https://doi.org/10.1109/TGRS.2019.2921980, 2019. a
Kluskiewicz, D., Waddington, E. D., Anandakrishnan, S., Voigt, D. E., Matsuoka,
K., and McCarthy, M. P.: Sonic Methods for Measuring Crystal Orientation
Fabric in Ice, and Results from the West Antarctic Ice Sheet (WAIS)
Divide, J. Glaciol., 63, 603–617, https://doi.org/10.1017/jog.2017.20,
2017. a
Kohnen, H.: The Temperature Dependence of Seismic Waves in Ice, J.
Glaciol., 13, 144–147, 1974. a
Krischke, A., Oechsner, U., and Kipfstuhl, S.: Rapid Microstructure
Analysis of Polar Ice Cores, Optik & Photonik, 10, 32–35,
https://doi.org/10.1002/opph.201500016, 2015. a
Langway, C. C., Shoji, H., and Azuma, N.: Crystal Size and Orientation
Patterns in the Wisconsin-Age Ice from Dye 3, Greenland,
Ann. Glaciol., 10, 109–115, https://doi.org/10.3189/S0260305500004262, 1988. a
Mainprice, D., Hielscher, R., and Schaeben, H.: Calculating Anisotropic
Physical Properties from Texture Data Using the MTEX Open-Source Package,
Geol. Soc. Spec. Publ., 360, 175–192,
https://doi.org/10.1144/SP360.10, 2011. a, b
Matsuoka, K., Furukawa, T., Fujita, S., Maeno, H., Uratsuka, S., Naruse, R.,
and Watanabe, O.: Crystal Orientation Fabrics within the Antarctic Ice
Sheet Revealed by a Multipolarization Plane and Dual-Frequency Radar Survey,
J. Geophys. Res.-Sol. Ea., 108, 2499,
https://doi.org/10.1029/2003JB002425, 2003. a
Maurel, A., Lund, F., and Montagnat, M.: Propagation of Elastic Waves through
Textured Polycrystals: Application to Ice, P. Roy. Soc. A, 471, 20140988,
https://doi.org/10.1098/rspa.2014.0988, 2015. a, b
Maurel, A., Mercier, J.-F., and Montagnat, M.: Critical investigation of calculation methods for the elastic velocities in anisotropic ice polycrystals, The Cryosphere, 10, 3063–3070, https://doi.org/10.5194/tc-10-3063-2016, 2016. a
Mikesell, T., van Wijk, K., Otheim, L., Marshall, H.-P., and Kurbatov, A.:
Laser Ultrasound Observations of Mechanical Property Variations in
Ice Cores, Geosciences, 7, 47, https://doi.org/10.3390/geosciences7030047, 2017. a
Monz, M. E., Hudleston, P. J., Prior, D. J., Michels, Z., Fan, S., Negrini, M., Langhorne, P. J., and Qi, C.: Full crystallographic orientation (c and a axes) of warm, coarse-grained ice in a shear-dominated setting: a case study, Storglaciären, Sweden, The Cryosphere, 15, 303–324, https://doi.org/10.5194/tc-15-303-2021, 2021. a, b, c
Nanthikesan, S. and Sunder, S.: Anisotropic Elasticity of Polycrystalline Ice
Ih, Cold Reg. Sci. Technol., 22, 149–169,
https://doi.org/10.1016/0165-232X(94)90026-4, 1994. a
Nguyen, X. V.: The Spherical K-Means Algorithm,
MATLAB Central File Exchange, available at:
https://ch.mathworks.com/matlabcentral/fileexchange/32987-the-spherical-k-means-algorithm, last access: 23 July 2020.
a
Peternell, M., Kohlmann, F., Wilson, C. J., Seiler, C., and Gleadow, A. J.: A
New Approach to Crystallographic Orientation Measurement for Apatite Fission
Track Analysis: Effects of Crystal Morphology and Implications for
Automation, Chem. Geol., 265, 527–539,
https://doi.org/10.1016/j.chemgeo.2009.05.021, 2009. a, b
Pettit, E. C., Thorsteinsson, T., Jacobson, H. P., and Waddington, E. D.: The
Role of Crystal Fabric in Flow near an Ice Divide, J. Glaciol., 53,
277–288, https://doi.org/10.3189/172756507782202766, 2007. a
Picotti, S., Vuan, A., Carcione, J. M., Horgan, H. J., and Anandakrishnan, S.:
Anisotropy and Crystalline Fabric of Whillans Ice Stream (West
Antarctica) Inferred from Multicomponent Seismic Data, J.
Geophys. Res.-Sol. Ea., 120, 4237–4262,
https://doi.org/10.1002/2014JB011591, 2015. a
Placidi, L., Greve, R., Seddik, H., and Faria, S. H.: Continuum-Mechanical,
Anisotropic Flow Model for Polar Ice Masses, Based on an Anisotropic
Flow Enhancement Factor, Continuum Mech. Therm., 22,
221–237, https://doi.org/10.1007/s00161-009-0126-0, 2010. a
Schwikowski, M., Jenk, T. M., Stampfli, D., and Stampfli, F.: A New Thermal
Drilling System for High-Altitude or Temperate Glaciers, Ann.
Glaciol., 55, 131–136, https://doi.org/10.3189/2014AoG68A024, 2014. a
Selvadurai, P. A.: Laboratory Insight Into Seismic Estimates of Energy
Partitioning During Dynamic Rupture: An Observable Scaling Breakdown,
J. Geophys. Res.-Sol. Ea., 124, 11350–11379,
https://doi.org/10.1029/2018JB017194, 2019. a
Torquato, S.: Random Heterogeneous Materials: Microstructure and Macroscopic
Properties, 16, in: Interdisciplinary Applied Mathematics, Springer,
New York, 2002. a
Voigt, W.: Lehrbuch Der Kristallphysik: Mit Ausschluss Der
Kristalloptik, vol. 12 of Bibliotheca Mathematica
Teubneriana, Teubner, Leipzig, Berlin, 1st Edn., 1910. a
Wallbrecher, E.: Tektonische Und Gefügeanalytische Arbeitsweisen:
Graphische, Rechnerische Und Statistische Verfahren, Enke, Stuttgart,
1986. a
Wilhelms, F.: Explaining the Dielectric Properties of Firn as a
Density-and-Conductivity Mixed Permittivity (DECOMP), Geophys.
Res. Lett, 32, L16501, https://doi.org/10.1029/2005GL022808, 2005. a
Wilhelms, F., Kipfstuhl, J., Miller, H., Heinloth, K., and Firestone, J.:
Precise Dielectric Profiling of Ice Cores: A New Device with Improved
Guarding and Its Theory, J. Glaciol., 44, 171–174,
https://doi.org/10.3189/S002214300000246X, 1998. a
Williamson, P. R. and Worthington, M. H.: Resolution Limits in Ray Tomography
Due to Wave Behavior: Numerical Experiments, Geophysics, 58, 727–735,
https://doi.org/10.1190/1.1443457, 1993. a
Short summary
In this study, we analyse whether ultrasonic measurements on ice core samples could be employed to derive information about the particular ice crystal orientation in these samples. We discuss if such ultrasonic scans of ice core samples could provide similarly detailed results as the established methods, which usually destroy the ice samples. Our geophysical approach is minimally invasive and could support the existing methods with additional and (semi-)continuous data points along the ice core.
In this study, we analyse whether ultrasonic measurements on ice core samples could be employed...
