Articles | Volume 16, issue 5
https://doi.org/10.5194/tc-16-2009-2022
© Author(s) 2022. 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-16-2009-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Can changes in deformation regimes be inferred from crystallographic preferred orientations in polar ice?
Maria-Gema Llorens
CORRESPONDING AUTHOR
Geosciencies Barcelona CSIC, Lluis Sole i Sabaris s/n, 08028
Barcelona, Spain
Albert Griera
Departament de Geologia, Universitat Autònoma de Barcelona, 08193
Cerdanyola del Vallès, Barcelona, Spain
Paul D. Bons
Department of Geosciences, Eberhard Karls University Tübingen,
Wilhemstr. 56, 72074 Tübingen, Germany
School of Earth Sciences and Resources, China University of Geosciences, Beijing, China
Ilka Weikusat
Department of Geosciences, Eberhard Karls University Tübingen,
Wilhemstr. 56, 72074 Tübingen, Germany
Alfred Wegener Institute Helmholtz Centre for Polar and Marine
Research, Bremerhaven, Germany
David J. Prior
Department of Geology, University of Otago, 362 Leith Street,
Dunedin 9016, New Zealand
Enrique Gomez-Rivas
Departament de Mineralogia, Petrologia i Geologia Aplicada,
Facultat de Ciències de la Terra, Universitat de Barcelona, Martí i
Franquès s/n, 08028 Barcelona, Spain
Tamara de Riese
Department of Geosciences, Eberhard Karls University Tübingen,
Wilhemstr. 56, 72074 Tübingen, Germany
Ivone Jimenez-Munt
Geosciencies Barcelona CSIC, Lluis Sole i Sabaris s/n, 08028
Barcelona, Spain
Daniel García-Castellanos
Geosciencies Barcelona CSIC, Lluis Sole i Sabaris s/n, 08028
Barcelona, Spain
Ricardo A. Lebensohn
Theoretical Division, Los Alamos National Laboratory, Los Alamos,
NM, 87545, USA
Related authors
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.
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.
Chao Qi, David J. Prior, Lisa Craw, Sheng Fan, Maria-Gema Llorens, Albert Griera, Marianne Negrini, Paul D. Bons, and David L. Goldsby
The Cryosphere, 13, 351–371, https://doi.org/10.5194/tc-13-351-2019, https://doi.org/10.5194/tc-13-351-2019, 2019
Short summary
Short summary
Ice deformed in nature develops crystallographic preferred orientations, CPOs, which induce an anisotropy in ice viscosity. Shear experiments of ice revealed a transition in CPO with changing temperature/strain, which is due to the change of dominant CPO-formation mechanism: strain-induced grain boundary migration dominates at higher temperatures and lower strains, while lattice rotation dominates at other conditions. Understanding these mechanisms aids the interpretation of CPOs in natural ice.
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.
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.
E. Gomez-Rivas, A. Griera, and M.-G. Llorens
Solid Earth, 6, 497–514, https://doi.org/10.5194/se-6-497-2015, https://doi.org/10.5194/se-6-497-2015, 2015
Konstantina Agiadi, Niklas Hohmann, Elsa Gliozzi, Danae Thivaiou, Francesca R. Bosellini, Marco Taviani, Giovanni Bianucci, Alberto Collareta, Laurent Londeix, Costanza Faranda, Francesca Bulian, Efterpi Koskeridou, Francesca Lozar, Alan Maria Mancini, Stefano Dominici, Pierre Moissette, Ildefonso Bajo Campos, Enrico Borghi, George Iliopoulos, Assimina Antonarakou, George Kontakiotis, Evangelia Besiou, Stergios D. Zarkogiannis, Mathias Harzhauser, Francisco Javier Sierro, Angelo Camerlenghi, and Daniel García-Castellanos
Earth Syst. Sci. Data, 16, 4767–4775, https://doi.org/10.5194/essd-16-4767-2024, https://doi.org/10.5194/essd-16-4767-2024, 2024
Short summary
Short summary
We present a dataset of 23032 fossil occurrences of marine organisms from the Late Miocene to the Early Pliocene (~11 to 3.6 million years ago) from the Mediterranean Sea. This dataset will allow us, for the first time, to quantify the biodiversity impact of the Messinian salinity crisis, a major geological event that possibly changed global and regional climate and biota.
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.
Steven Franke, Daniel Steinhage, Veit Helm, Alexandra M. Zuhr, Julien A. Bodart, Olaf Eisen, and Paul Bons
EGUsphere, https://doi.org/10.5194/egusphere-2024-2349, https://doi.org/10.5194/egusphere-2024-2349, 2024
Short summary
Short summary
We use radar technology to study the internal architecture of the ice sheet in western DML, East Antarctica. We identified and dated nine internal reflection horizons (IRHs), revealing important information about the ice sheet's history and dynamics. Some IRHs can be linked to past volcanic eruptions and are of similar age to IRHs detected in other parts of Antarctica. Our findings enhance our understanding of ice sheet behaviour and aid in developing better models for predicting future changes.
Montserrat Torne, Tiago Alves, Ivone Jiménez-Munt, Joao Carvalho, Conxi Ayala, Elsa Ramalho, Angela Gómez, Hugo Matias, Hanneke Heida, Abraham Balaguera, José Luis García-Lobón, and Jaume Vergés
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-210, https://doi.org/10.5194/essd-2024-210, 2024
Preprint under review for ESSD
Short summary
Short summary
Sediments are like history books for geologists and geophysicists. By studying sediments, we can learn about past environments, sea level and climate changes, and where the sediments came from. To aid in understanding the geology, georesources, and potential hazards in the Iberian Peninsula and surrounding seas, we present the SedDARE-IB sediments data repository. As an application in geothermal exploration, we investigate how sediments thickness affects the depth of the 150 °C isotherm.
Qinyu Wang, Sheng Fan, Daniel H. Richards, Rachel Worthington, David J. Prior, and Chao Qi
EGUsphere, https://doi.org/10.5194/egusphere-2024-331, https://doi.org/10.5194/egusphere-2024-331, 2024
Short summary
Short summary
To examine if the single cluster fabric in natural ice is formed due to high strains, we deformed synthetic ice to large strains using a unique technique. A shear strain of 6.2 was achieved in laboratory. We explored how the two mechanisms, which control microstructure and fabric evolution, evolve with strain, and established a fabric development model. These results will help understanding the fabrics in natural ice and further comprehending glacier and ice sheet flow dynamics.
Johanna Heeb, David Healy, Nicholas E. Timms, and Enrique Gomez-Rivas
Solid Earth, 14, 985–1003, https://doi.org/10.5194/se-14-985-2023, https://doi.org/10.5194/se-14-985-2023, 2023
Short summary
Short summary
Hydration of rocks is a key process in the Earth’s crust and mantle that is accompanied by changes in physical traits and mechanical behaviour of rocks. This study assesses the influence of stress on hydration reaction kinetics and mechanics in experiments on anhydrite. We show that hydration occurs readily under stress and results in localized hydration along fractures and mechanic weakening. New gypsum growth is selective and depends on the stress field and host anhydrite crystal orientation.
Sheng Fan, David J. Prior, Brent Pooley, Hamish Bowman, Lucy Davidson, David Wallis, Sandra Piazolo, Chao Qi, David L. Goldsby, and Travis F. Hager
The Cryosphere, 17, 3443–3459, https://doi.org/10.5194/tc-17-3443-2023, https://doi.org/10.5194/tc-17-3443-2023, 2023
Short summary
Short summary
The microstructure of ice controls the behaviour of polar ice flow. Grain growth can modify the microstructure of ice; however, its processes and kinetics are poorly understood. We conduct grain-growth experiments on synthetic and natural ice samples at 0 °C. Microstructural data show synthetic ice grows continuously with time. In contrast, natural ice does not grow within a month. The inhibition of grain growth in natural ice is largely contributed by bubble pinning at ice grain boundaries.
Eloi González-Esvertit, Juan Alcalde, and Enrique Gomez-Rivas
Earth Syst. Sci. Data, 15, 3131–3145, https://doi.org/10.5194/essd-15-3131-2023, https://doi.org/10.5194/essd-15-3131-2023, 2023
Short summary
Short summary
Evaporites are, scientifically and economically, key rocks due to their unique geological features and value for industrial purposes. To compile and normalise the vast amount of information of evaporite structures in the Iberian Peninsula, we present the IESDB – the first comprehensive database of evaporite structures and their surrounding rocks in Spain and Portugal. The IESDB is free to use, open access, and can be accessed and downloaded through the interactive IESDB webpage.
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.
Till Sachau, Haibin Yang, Justin Lang, Paul D. Bons, and Louis Moresi
Geosci. Model Dev., 15, 8749–8764, https://doi.org/10.5194/gmd-15-8749-2022, https://doi.org/10.5194/gmd-15-8749-2022, 2022
Short summary
Short summary
Knowledge of the internal structures of the major continental ice sheets is improving, thanks to new investigative techniques. These structures are an essential indication of the flow behavior and dynamics of ice transport, which in turn is important for understanding the actual impact of the vast amounts of water trapped in continental ice sheets on global sea-level rise. The software studied here is specifically designed to simulate such structures and their evolution.
Franz Lutz, David J. Prior, Holly Still, M. Hamish Bowman, Bia Boucinhas, Lisa Craw, Sheng Fan, Daeyeong Kim, Robert Mulvaney, Rilee E. Thomas, and Christina L. Hulbe
The Cryosphere, 16, 3313–3329, https://doi.org/10.5194/tc-16-3313-2022, https://doi.org/10.5194/tc-16-3313-2022, 2022
Short summary
Short summary
Ice crystal alignment in the sheared margins of fast-flowing polar ice is important as it may control the ice sheet flow rate, from land to the ocean. Sampling shear margins is difficult because of logistical and safety considerations. We show that crystal alignments in a glacier shear margin in Antarctica can be measured using sound waves. Results from a seismic experiment on the 50 m scale and from ultrasonic experiments on the decimetre scale match ice crystal measurements from an ice core.
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.
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.
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.
Sebastian Hellmann, Melchior Grab, Johanna Kerch, Henning Löwe, Andreas Bauder, Ilka Weikusat, and Hansruedi Maurer
The Cryosphere, 15, 3507–3521, https://doi.org/10.5194/tc-15-3507-2021, https://doi.org/10.5194/tc-15-3507-2021, 2021
Short summary
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.
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.
Morgan E. Monz, Peter J. Hudleston, David J. Prior, Zachary Michels, Sheng Fan, Marianne Negrini, Pat J. Langhorne, and Chao Qi
The Cryosphere, 15, 303–324, https://doi.org/10.5194/tc-15-303-2021, https://doi.org/10.5194/tc-15-303-2021, 2021
Short summary
Short summary
We present full crystallographic orientations of warm, coarse-grained ice deformed in a shear setting, enabling better characterization of how crystals in glacial ice preferentially align as ice flows. A commonly noted c-axis pattern, with several favored orientations, may result from bias due to overcounting large crystals with complex 3D shapes. A new sample preparation method effectively increases the sample size and reduces bias, resulting in a simpler pattern consistent with the ice flow.
Sheng Fan, Travis F. Hager, David J. Prior, Andrew J. Cross, David L. Goldsby, Chao Qi, Marianne Negrini, and John Wheeler
The Cryosphere, 14, 3875–3905, https://doi.org/10.5194/tc-14-3875-2020, https://doi.org/10.5194/tc-14-3875-2020, 2020
Short summary
Short summary
We performed uniaxial compression experiments on synthetic ice samples. We report ice microstructural evolution at –20 and –30 °C that has never been reported before. Microstructural data show the opening angle of c-axis cones decreases with increasing strain or with decreasing temperature, suggesting a more active grain rotation. CPO intensity weakens with temperature because CPO of small grains is weaker, and it can be explained by grain boundary sliding or nucleation with random orientations.
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.
Chao Qi, David J. Prior, Lisa Craw, Sheng Fan, Maria-Gema Llorens, Albert Griera, Marianne Negrini, Paul D. Bons, and David L. Goldsby
The Cryosphere, 13, 351–371, https://doi.org/10.5194/tc-13-351-2019, https://doi.org/10.5194/tc-13-351-2019, 2019
Short summary
Short summary
Ice deformed in nature develops crystallographic preferred orientations, CPOs, which induce an anisotropy in ice viscosity. Shear experiments of ice revealed a transition in CPO with changing temperature/strain, which is due to the change of dominant CPO-formation mechanism: strain-induced grain boundary migration dominates at higher temperatures and lower strains, while lattice rotation dominates at other conditions. Understanding these mechanisms aids the interpretation of CPOs in natural ice.
Steven B. Kidder, Virginia G. Toy, David J. Prior, Timothy A. Little, Ashfaq Khan, and Colin MacRae
Solid Earth, 9, 1123–1139, https://doi.org/10.5194/se-9-1123-2018, https://doi.org/10.5194/se-9-1123-2018, 2018
Short summary
Short summary
By quantifying trace concentrations of titanium in quartz (a known geologic “thermometer”), we constrain the temperature profile for the deep crust along the Alpine Fault. We show there is a sharp change from fairly uniform temperatures at deep levels to a very steep gradient in temperature in the upper kilometers of the crust.
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.
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.
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.
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.
Matthew J. Vaughan, Kasper van Wijk, David J. Prior, and M. Hamish Bowman
The Cryosphere, 10, 2821–2829, https://doi.org/10.5194/tc-10-2821-2016, https://doi.org/10.5194/tc-10-2821-2016, 2016
Short summary
Short summary
The physical properties of ice are of interest in the study of the dynamics of sea ice, glaciers, and ice sheets. We used resonant ultrasound spectroscopy to estimate the effects of temperature on the elastic and anelastic characteristics of polycrystalline ice, which control the propagation of sound waves. This information helps calibrate seismic data, in order to determine regional-scale ice properties, improving our ability to predict ice sheet behaviour in response to climate change.
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.
E. Gomez-Rivas, A. Griera, and M.-G. Llorens
Solid Earth, 6, 497–514, https://doi.org/10.5194/se-6-497-2015, https://doi.org/10.5194/se-6-497-2015, 2015
Z. Zhao, P. D. Bons, G. Wang, A. Soesoo, and Y. Liu
Solid Earth, 6, 457–473, https://doi.org/10.5194/se-6-457-2015, https://doi.org/10.5194/se-6-457-2015, 2015
Short summary
Short summary
The early Mesozoic tectonic history of the Qiangtang terrane in central Tibet is hotly debated. We argue that the north and south Qiangtang terranes were separated by an ocean (Paleo-Tethys) until the late Triassic. Subduction was mainly to the north, underneath the north Qiangtang terrane. The high-pressure rocks were exhumed in a lithospheric-scale core complex. Together with non-metamorphic sedimentary and ophiolitic mélange, these were finally thrust on top of the south Qiangtang.
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
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
Related subject area
Discipline: Ice sheets | Subject: Numerical Modelling
Antarctic sensitivity to oceanic melting parameterizations
Analytical solutions for the advective–diffusive ice column in the presence of strain heating
Ice viscosity governs hydraulic fracture that causes rapid drainage of supraglacial lakes
Biases in ice sheet models from missing noise-induced drift
Sensitivity of Future Projections of the Wilkes Subglacial Basin Ice Sheet to Grounding Line Melt Parameterizations
Modeling the timing of Patagonian Ice Sheet retreat in the Chilean Lake District from 22–10 ka
Using specularity content to evaluate eight geothermal heat flow maps of Totten Glacier
Surging of a Hudson Strait-scale ice stream: subglacial hydrology matters but the process details mostly do not
Coupling between ice flow and subglacial hydrology enhances marine ice-sheet retreat
Regularization and L-curves in ice sheet inverse models: a case study in the Filchner–Ronne catchment
Quantifying the uncertainty in the Eurasian ice-sheet geometry at the Penultimate Glacial Maximum (Marine Isotope Stage 6)
The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded
The stability of present-day Antarctic grounding lines – Part 1: No indication of marine ice sheet instability in the current geometry
Geothermal heat flux is the dominant source of uncertainty in englacial-temperature-based dating of ice rise formation
Improving interpretation of sea-level projections through a machine-learning-based local explanation approach
Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing
The predictive power of ice sheet models and the regional sensitivity of ice loss to basal sliding parameterisations: a case study of Pine Island and Thwaites glaciers, West Antarctica
Simulations of firn processes over the Greenland and Antarctic ice sheets: 1980–2021
Evaluation of six geothermal heat flux maps for the Antarctic Lambert–Amery glacial system
Impact of runoff temporal distribution on ice dynamics
Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet
Effective coefficient of diffusion and permeability of firn at Dome C and Lock In, Antarctica, and of various snow types – estimates over the 100–850 kg m−3 density range
The instantaneous impact of calving and thinning on the Larsen C Ice Shelf
Derivation of bedrock topography measurement requirements for the reduction of uncertainty in ice-sheet model projections of Thwaites Glacier
A comparison of the stability and performance of depth-integrated ice-dynamics solvers
A new vertically integrated MOno-Layer Higher-Order (MOLHO) ice flow model
On the contribution of grain boundary sliding type creep to firn densification – an assessment using an optimization approach
Marine ice sheet experiments with the Community Ice Sheet Model
The transferability of adjoint inversion products between different ice flow models
Inferring the basal sliding coefficient field for the Stokes ice sheet model under rheological uncertainty
The tipping points and early warning indicators for Pine Island Glacier, West Antarctica
Sensitivity of ice sheet surface velocity and elevation to variations in basal friction and topography in the full Stokes and shallow-shelf approximation frameworks using adjoint equations
Quantifying the effect of ocean bed properties on ice sheet geometry over 40 000 years with a full-Stokes model
Bayesian calibration of firn densification models
A kinematic formalism for tracking ice–ocean mass exchange on the Earth's surface and estimating sea-level change
Results of the third Marine Ice Sheet Model Intercomparison Project (MISMIP+)
Ocean-forced evolution of the Amundsen Sea catchment, West Antarctica, by 2100
Parameter sensitivity analysis of dynamic ice sheet models – numerical computations
Simulated retreat of Jakobshavn Isbræ during the 21st century
Development of physically based liquid water schemes for Greenland firn-densification models
Regional grid refinement in an Earth system model: impacts on the simulated Greenland surface mass balance
initMIP-Antarctica: an ice sheet model initialization experiment of ISMIP6
Modeling the response of northwest Greenland to enhanced ocean thermal forcing and subglacial discharge
Assessment of the Greenland ice sheet–atmosphere feedbacks for the next century with a regional atmospheric model coupled to an ice sheet model
Sensitivity of centennial mass loss projections of the Amundsen basin to the friction law
Retreat of Thwaites Glacier, West Antarctica, over the next 100 years using various ice flow models, ice shelf melt scenarios and basal friction laws
Comparison of four calving laws to model Greenland outlet glaciers
Neutral equilibrium and forcing feedbacks in marine ice sheet modelling
Representation of basal melting at the grounding line in ice flow models
Stopping the flood: could we use targeted geoengineering to mitigate sea level rise?
Antonio Juarez-Martinez, Javier Blasco, Alexander Robinson, Marisa Montoya, and Jorge Alvarez-Solas
The Cryosphere, 18, 4257–4283, https://doi.org/10.5194/tc-18-4257-2024, https://doi.org/10.5194/tc-18-4257-2024, 2024
Short summary
Short summary
We present sea level projections for Antarctica in the context of ISMIP6-2300 with several forcings but extend the simulations to 2500, showing that more than 3 m of sea level contribution could be reached. We also test the sensitivity on a basal melting parameter and determine the timing of the loss of ice in the west region. All the simulations were carried out with the ice sheet model Yelmo.
Daniel Moreno-Parada, Alexander Robinson, Marisa Montoya, and Jorge Alvarez-Solas
The Cryosphere, 18, 4215–4232, https://doi.org/10.5194/tc-18-4215-2024, https://doi.org/10.5194/tc-18-4215-2024, 2024
Short summary
Short summary
Our study tries to understand how the ice temperature evolves in a large mass as in the case of Antarctica. We found a relation that tells us the ice temperature at any point. These results are important because they also determine how the ice moves. In general, ice moves due to slow deformation (as if pouring honey from a jar). Nevertheless, in some regions the ice base warms enough and melts. The liquid water then serves as lubricant and the ice slides and its velocity increases rapidly.
Tim Hageman, Jessica Mejía, Ravindra Duddu, and Emilio Martínez-Pañeda
The Cryosphere, 18, 3991–4009, https://doi.org/10.5194/tc-18-3991-2024, https://doi.org/10.5194/tc-18-3991-2024, 2024
Short summary
Short summary
Due to surface melting, meltwater lakes seasonally form on the surface of glaciers. These lakes drive hydrofractures that rapidly transfer water to the base of ice sheets. This paper presents a computational method to capture the complicated hydrofracturing process. Our work reveals that viscous ice rheology has a great influence on the short-term propagation of fractures, enabling fast lake drainage, whereas thermal effects (frictional heating, conduction, and freezing) have little influence.
Alexander A. Robel, Vincent Verjans, and Aminat A. Ambelorun
The Cryosphere, 18, 2613–2623, https://doi.org/10.5194/tc-18-2613-2024, https://doi.org/10.5194/tc-18-2613-2024, 2024
Short summary
Short summary
The average size of many glaciers and ice sheets changes when noise is added to the system. The reasons for this drift in glacier state is intrinsic to the dynamics of how ice flows and the bumpiness of the Earth's surface. We argue that not including noise in projections of ice sheet evolution over coming decades and centuries is a pervasive source of bias in these computer models, and so realistic variability in glacier and climate processes must be included in models.
Yu Wang, Chen Zhao, Rupert Gladstone, Thomas Zwinger, Ben Galton-Fenzi, and Poul Christoffersen
EGUsphere, https://doi.org/10.5194/egusphere-2024-1005, https://doi.org/10.5194/egusphere-2024-1005, 2024
Short summary
Short summary
Our research delves into the future ice loss in Antarctica’s Wilkes Subglacial Basin (WSB) and its impact on sea level rise, focusing on how basal melt is implemented at the grounding line in ice flow models. According to our best model results, under high-emission scenarios, the WSB ice sheet could undergo massive and rapid retreat between 2200 and 2300, potentially raising global sea levels by up to 0.34 m by 2500.
Joshua Cuzzone, Matias Romero, and Shaun A. Marcott
The Cryosphere, 18, 1381–1398, https://doi.org/10.5194/tc-18-1381-2024, https://doi.org/10.5194/tc-18-1381-2024, 2024
Short summary
Short summary
We simulate the retreat history of the Patagonian Ice Sheet (PIS) across the Chilean Lake District from 22–10 ka. These results improve our understanding of the response of the PIS to deglacial warming and the patterns of deglacial ice margin retreat where gaps in the geologic record still exist, and they indicate that changes in large-scale precipitation during the last deglaciation played an important role in modulating the response of ice margin change across the PIS to deglacial warming.
Yan Huang, Liyun Zhao, Michael Wolovick, Yiliang Ma, and John C. Moore
The Cryosphere, 18, 103–119, https://doi.org/10.5194/tc-18-103-2024, https://doi.org/10.5194/tc-18-103-2024, 2024
Short summary
Short summary
Geothermal heat flux (GHF) is an important factor affecting the basal thermal environment of an ice sheet and crucial for its dynamics. But it is poorly defined for the Antarctic ice sheet. We simulate the basal temperature and basal melting rate with eight different GHF datasets. We use specularity content as a two-sided constraint to discriminate between local wet or dry basal conditions. Two medium-magnitude GHF distribution maps rank well, showing that most of the inland bed area is frozen.
Matthew Drew and Lev Tarasov
The Cryosphere, 17, 5391–5415, https://doi.org/10.5194/tc-17-5391-2023, https://doi.org/10.5194/tc-17-5391-2023, 2023
Short summary
Short summary
The interaction of fast-flowing regions of continental ice sheets with their beds governs how quickly they slide and therefore flow. The coupling of fast ice to its bed is controlled by the pressure of meltwater at its base. It is currently poorly understood how the physical details of these hydrologic systems affect ice speedup. Using numerical models we find, surprisingly, that they largely do not, except for the duration of the surge. This suggests that cheap models are sufficient.
George Lu and Jonathan Kingslake
EGUsphere, https://doi.org/10.5194/egusphere-2023-2794, https://doi.org/10.5194/egusphere-2023-2794, 2023
Short summary
Short summary
Water below ice sheets affects ice-sheet motion, while the evolution of ice sheets likewise affects the water below. We create a model that allows for water and ice to affect each other, and use it to see how this coupling or lack thereof may impact ice-sheet retreat. We find that coupling an evolving water system with the ice sheet results in more retreat than if we assume unchanging conditions under the ice, which indicates a need to better represent the effects of water in ice-sheet models.
Michael Wolovick, Angelika Humbert, Thomas Kleiner, and Martin Rückamp
The Cryosphere, 17, 5027–5060, https://doi.org/10.5194/tc-17-5027-2023, https://doi.org/10.5194/tc-17-5027-2023, 2023
Short summary
Short summary
The friction underneath ice sheets can be inferred from observed velocity at the top, but this inference requires smoothing. The selection of smoothing has been highly variable in the literature. Here we show how to rigorously select the best smoothing, and we show that the inferred friction converges towards the best knowable field as model resolution improves. We use this to learn about the best description of basal friction and to formulate recommended best practices for other modelers.
Oliver G. Pollard, Natasha L. M. Barlow, Lauren J. Gregoire, Natalya Gomez, Víctor Cartelle, Jeremy C. Ely, and Lachlan C. Astfalck
The Cryosphere, 17, 4751–4777, https://doi.org/10.5194/tc-17-4751-2023, https://doi.org/10.5194/tc-17-4751-2023, 2023
Short summary
Short summary
We use advanced statistical techniques and a simple ice-sheet model to produce an ensemble of plausible 3D shapes of the ice sheet that once stretched across northern Europe during the previous glacial maximum (140,000 years ago). This new reconstruction, equivalent in volume to 48 ± 8 m of global mean sea-level rise, will improve the interpretation of high sea levels recorded from the Last Interglacial period (120 000 years ago) that provide a useful perspective on the future.
Ronja Reese, Julius Garbe, Emily A. Hill, Benoît Urruty, Kaitlin A. Naughten, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, David Chandler, Petra M. Langebroek, and Ricarda Winkelmann
The Cryosphere, 17, 3761–3783, https://doi.org/10.5194/tc-17-3761-2023, https://doi.org/10.5194/tc-17-3761-2023, 2023
Short summary
Short summary
We use an ice sheet model to test where current climate conditions in Antarctica might lead. We find that present-day ocean and atmosphere conditions might commit an irreversible collapse of parts of West Antarctica which evolves over centuries to millennia. Importantly, this collapse is not irreversible yet.
Emily A. Hill, Benoît Urruty, Ronja Reese, Julius Garbe, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, Ricarda Winkelmann, Mondher Chekki, David Chandler, and Petra M. Langebroek
The Cryosphere, 17, 3739–3759, https://doi.org/10.5194/tc-17-3739-2023, https://doi.org/10.5194/tc-17-3739-2023, 2023
Short summary
Short summary
The grounding lines of the Antarctic Ice Sheet could enter phases of irreversible retreat or advance. We use three ice sheet models to show that the present-day locations of Antarctic grounding lines are reversible with respect to a small perturbation away from their current position. This indicates that present-day retreat of the grounding lines is not yet irreversible or self-enhancing.
Aleksandr Montelli and Jonathan Kingslake
The Cryosphere, 17, 195–210, https://doi.org/10.5194/tc-17-195-2023, https://doi.org/10.5194/tc-17-195-2023, 2023
Short summary
Short summary
Thermal modelling and Bayesian inversion techniques are used to evaluate the uncertainties inherent in inferences of ice-sheet evolution from borehole temperature measurements. We show that the same temperature profiles may result from a range of parameters, of which geothermal heat flux through underlying bedrock plays a key role. Careful model parameterisation and evaluation of heat flux are essential for inferring past ice-sheet evolution from englacial borehole thermometry.
Jeremy Rohmer, Remi Thieblemont, Goneri Le Cozannet, Heiko Goelzer, and Gael Durand
The Cryosphere, 16, 4637–4657, https://doi.org/10.5194/tc-16-4637-2022, https://doi.org/10.5194/tc-16-4637-2022, 2022
Short summary
Short summary
To improve the interpretability of process-based projections of the sea-level contribution from land ice components, we apply the machine-learning-based
SHapley Additive exPlanationsapproach to a subset of a multi-model ensemble study for the Greenland ice sheet. This allows us to quantify the influence of particular modelling decisions (related to numerical implementation, initial conditions, or parametrisation of ice-sheet processes) directly in terms of sea-level change contribution.
Elise Kazmierczak, Sainan Sun, Violaine Coulon, and Frank Pattyn
The Cryosphere, 16, 4537–4552, https://doi.org/10.5194/tc-16-4537-2022, https://doi.org/10.5194/tc-16-4537-2022, 2022
Short summary
Short summary
The water at the interface between ice sheets and underlying bedrock leads to lubrication between the ice and the bed. Due to a lack of direct observations, subglacial conditions beneath the Antarctic ice sheet are poorly understood. Here, we compare different approaches in which the subglacial water could influence sliding on the underlying bedrock and suggest that it modulates the Antarctic ice sheet response and increases uncertainties, especially in the context of global warming.
Jowan M. Barnes and G. Hilmar Gudmundsson
The Cryosphere, 16, 4291–4304, https://doi.org/10.5194/tc-16-4291-2022, https://doi.org/10.5194/tc-16-4291-2022, 2022
Short summary
Short summary
Models must represent how glaciers slide along the bed, but there are many ways to do so. In this paper, several sliding laws are tested and found to affect different regions of the Antarctic Ice Sheet in different ways and at different speeds. However, the variability in ice volume loss due to sliding-law choices is low compared to other factors, so limited empirical knowledge of sliding does not prevent us from making predictions of how an ice sheet will evolve.
Brooke Medley, Thomas A. Neumann, H. Jay Zwally, Benjamin E. Smith, and C. Max Stevens
The Cryosphere, 16, 3971–4011, https://doi.org/10.5194/tc-16-3971-2022, https://doi.org/10.5194/tc-16-3971-2022, 2022
Short summary
Short summary
Satellite altimeters measure the height or volume change over Earth's ice sheets, but in order to understand how that change translates into ice mass, we must account for various processes at the surface. Specifically, snowfall events generate large, transient increases in surface height, yet snow fall has a relatively low density, which means much of that height change is composed of air. This air signal must be removed from the observed height changes before we can assess ice mass change.
Haoran Kang, Liyun Zhao, Michael Wolovick, and John C. Moore
The Cryosphere, 16, 3619–3633, https://doi.org/10.5194/tc-16-3619-2022, https://doi.org/10.5194/tc-16-3619-2022, 2022
Short summary
Short summary
Basal thermal conditions are important to ice dynamics and sensitive to geothermal heat flux (GHF). We estimate basal thermal conditions of the Lambert–Amery Glacier system with six GHF maps. Recent GHFs inverted from aerial geomagnetic observations produce a larger warm-based area and match the observed subglacial lakes better than the other GHFs. The modelled basal melt rate is 10 to hundreds of millimetres per year in fast-flowing glaciers feeding the Amery Ice Shelf and smaller inland.
Basile de Fleurian, Richard Davy, and Petra M. Langebroek
The Cryosphere, 16, 2265–2283, https://doi.org/10.5194/tc-16-2265-2022, https://doi.org/10.5194/tc-16-2265-2022, 2022
Short summary
Short summary
As temperature increases, more snow and ice melt at the surface of ice sheets. Here we use an ice dynamics and subglacial hydrology model with simplified geometry and climate forcing to study the impact of variations in meltwater on ice dynamics. We focus on the variations in length and intensity of the melt season. Our results show that a longer melt season leads to faster glaciers, but a more intense melt season reduces glaciers' seasonal velocities, albeit leading to higher peak velocities.
Tanja Schlemm, Johannes Feldmann, Ricarda Winkelmann, and Anders Levermann
The Cryosphere, 16, 1979–1996, https://doi.org/10.5194/tc-16-1979-2022, https://doi.org/10.5194/tc-16-1979-2022, 2022
Short summary
Short summary
Marine cliff instability, if it exists, could dominate Antarctica's contribution to future sea-level rise. It is likely to speed up with ice thickness and thus would accelerate in most parts of Antarctica. Here, we investigate a possible mechanism that might stop cliff instability through cloaking by ice mélange. It is only a first step, but it shows that embayment geometry is, in principle, able to stop marine cliff instability in most parts of West Antarctica.
Neige Calonne, Alexis Burr, Armelle Philip, Frédéric Flin, and Christian Geindreau
The Cryosphere, 16, 967–980, https://doi.org/10.5194/tc-16-967-2022, https://doi.org/10.5194/tc-16-967-2022, 2022
Short summary
Short summary
Modeling gas transport in ice sheets from surface to close-off is key to interpreting climate archives. Estimates of the diffusion coefficient and permeability of snow and firn are required but remain a large source of uncertainty. We present a new dataset of diffusion coefficients and permeability from 20 to 120 m depth at two Antarctic sites. We suggest predictive formulas to estimate both properties over the entire 100–850 kg m3 density range, i.e., anywhere within the ice sheet column.
Tom Mitcham, G. Hilmar Gudmundsson, and Jonathan L. Bamber
The Cryosphere, 16, 883–901, https://doi.org/10.5194/tc-16-883-2022, https://doi.org/10.5194/tc-16-883-2022, 2022
Short summary
Short summary
We modelled the response of the Larsen C Ice Shelf (LCIS) and its tributary glaciers to the calving of the A68 iceberg and validated our results with observations. We found that the impact was limited, confirming that mostly passive ice was calved. Through further calving experiments we quantified the total buttressing provided by the LCIS and found that over 80 % of the buttressing capacity is generated in the first 5 km of the ice shelf downstream of the grounding line.
Blake A. Castleman, Nicole-Jeanne Schlegel, Lambert Caron, Eric Larour, and Ala Khazendar
The Cryosphere, 16, 761–778, https://doi.org/10.5194/tc-16-761-2022, https://doi.org/10.5194/tc-16-761-2022, 2022
Short summary
Short summary
In the described study, we derive an uncertainty range for global mean sea level rise (SLR) contribution from Thwaites Glacier in a 200-year period under an extreme ocean warming scenario. We derive the spatial and vertical resolutions needed for bedrock data acquisition missions in order to limit global mean SLR contribution from Thwaites Glacier to ±2 cm in a 200-year period. We conduct sensitivity experiments in order to present the locations of critical regions in need of accurate mapping.
Alexander Robinson, Daniel Goldberg, and William H. Lipscomb
The Cryosphere, 16, 689–709, https://doi.org/10.5194/tc-16-689-2022, https://doi.org/10.5194/tc-16-689-2022, 2022
Short summary
Short summary
Here we investigate the numerical stability of several commonly used methods in order to determine which of them are capable of resolving the complex physics of the ice flow and are also computationally efficient. We find that the so-called DIVA solver outperforms the others. Its representation of the physics is consistent with more complex methods, while it remains computationally efficient at high resolution.
Thiago Dias dos Santos, Mathieu Morlighem, and Douglas Brinkerhoff
The Cryosphere, 16, 179–195, https://doi.org/10.5194/tc-16-179-2022, https://doi.org/10.5194/tc-16-179-2022, 2022
Short summary
Short summary
Projecting the future evolution of Greenland and Antarctica and their potential contribution to sea level rise often relies on computer simulations carried out by numerical ice sheet models. Here we present a new vertically integrated ice sheet model and assess its performance using different benchmarks. The new model shows results comparable to a three-dimensional model at relatively lower computational cost, suggesting that it is an excellent alternative for long-term simulations.
Timm Schultz, Ralf Müller, Dietmar Gross, and Angelika Humbert
The Cryosphere, 16, 143–158, https://doi.org/10.5194/tc-16-143-2022, https://doi.org/10.5194/tc-16-143-2022, 2022
Short summary
Short summary
Firn is the interstage product between snow and ice. Simulations describing the process of firn densification are used in the context of estimating mass changes of the ice sheets and past climate reconstructions. The first stage of firn densification takes place in the upper few meters of the firn column. We investigate how well a material law describing the process of grain boundary sliding works for the numerical simulation of firn densification in this stage.
Gunter R. Leguy, William H. Lipscomb, and Xylar S. Asay-Davis
The Cryosphere, 15, 3229–3253, https://doi.org/10.5194/tc-15-3229-2021, https://doi.org/10.5194/tc-15-3229-2021, 2021
Short summary
Short summary
We present numerical features of the Community Ice Sheet Model in representing ocean termini glaciers. Using idealized test cases, we show that applying melt in a partly grounded cell is beneficial, in contrast to recent studies. We confirm that parameterizing partly grounded cells yields accurate ice sheet representation at a grid resolution of ~2 km (arguably 4 km), allowing ice sheet simulations at a continental scale. The choice of basal friction law also influences the ice flow.
Jowan M. Barnes, Thiago Dias dos Santos, Daniel Goldberg, G. Hilmar Gudmundsson, Mathieu Morlighem, and Jan De Rydt
The Cryosphere, 15, 1975–2000, https://doi.org/10.5194/tc-15-1975-2021, https://doi.org/10.5194/tc-15-1975-2021, 2021
Short summary
Short summary
Some properties of ice flow models must be initialised using observed data before they can be used to produce reliable predictions of the future. Different models have different ways of doing this, and the process is generally seen as being specific to an individual model. We compare the methods used by three different models and show that they produce similar outputs. We also demonstrate that the outputs from one model can be used in other models without introducing large uncertainties.
Olalekan Babaniyi, Ruanui Nicholson, Umberto Villa, and Noémi Petra
The Cryosphere, 15, 1731–1750, https://doi.org/10.5194/tc-15-1731-2021, https://doi.org/10.5194/tc-15-1731-2021, 2021
Short summary
Short summary
We consider the problem of inferring unknown parameter fields under additional uncertainty for an ice sheet model from synthetic surface ice flow velocity measurements. Our results indicate that accounting for model uncertainty stemming from the presence of nuisance parameters is crucial. Namely our findings suggest that using nominal values for these parameters, as is often done in practice, without taking into account the resulting modeling error can lead to overconfident and biased results.
Sebastian H. R. Rosier, Ronja Reese, Jonathan F. Donges, Jan De Rydt, G. Hilmar Gudmundsson, and Ricarda Winkelmann
The Cryosphere, 15, 1501–1516, https://doi.org/10.5194/tc-15-1501-2021, https://doi.org/10.5194/tc-15-1501-2021, 2021
Short summary
Short summary
Pine Island Glacier has contributed more to sea-level rise over the past decades than any other glacier in Antarctica. Ice-flow modelling studies have shown that it can undergo periods of rapid mass loss, but no study has shown that these future changes could cross a tipping point and therefore be effectively irreversible. Here, we assess the stability of Pine Island Glacier, quantifying the changes in ocean temperatures required to cross future tipping points using statistical methods.
Gong Cheng, Nina Kirchner, and Per Lötstedt
The Cryosphere, 15, 715–742, https://doi.org/10.5194/tc-15-715-2021, https://doi.org/10.5194/tc-15-715-2021, 2021
Short summary
Short summary
We present an inverse modeling approach to improve the understanding of spatiotemporally variable processes at the inaccessible base of an ice sheet by determining the sensitivity of direct surface observations to perturbations of basal conditions. Time dependency is proved to be important in these types of problems. The effect of perturbations is analyzed based on analytical and numerical solutions.
Clemens Schannwell, Reinhard Drews, Todd A. Ehlers, Olaf Eisen, Christoph Mayer, Mika Malinen, Emma C. Smith, and Hannes Eisermann
The Cryosphere, 14, 3917–3934, https://doi.org/10.5194/tc-14-3917-2020, https://doi.org/10.5194/tc-14-3917-2020, 2020
Short summary
Short summary
To reduce uncertainties associated with sea level rise projections, an accurate representation of ice flow is paramount. Most ice sheet models rely on simplified versions of the underlying ice flow equations. Due to the high computational costs, ice sheet models based on the complete ice flow equations have been restricted to < 1000 years. Here, we present a new model setup that extends the applicability of such models by an order of magnitude, permitting simulations of 40 000 years.
Vincent Verjans, Amber A. Leeson, Christopher Nemeth, C. Max Stevens, Peter Kuipers Munneke, Brice Noël, and Jan Melchior van Wessem
The Cryosphere, 14, 3017–3032, https://doi.org/10.5194/tc-14-3017-2020, https://doi.org/10.5194/tc-14-3017-2020, 2020
Short summary
Short summary
Ice sheets are covered by a firn layer, which is the transition stage between fresh snow and ice. Accurate modelling of firn density properties is important in many glaciological aspects. Current models show disagreements, are mostly calibrated to match specific observations of firn density and lack thorough uncertainty analysis. We use a novel calibration method for firn models based on a Bayesian statistical framework, which results in improved model accuracy and in uncertainty evaluation.
Surendra Adhikari, Erik R. Ivins, Eric Larour, Lambert Caron, and Helene Seroussi
The Cryosphere, 14, 2819–2833, https://doi.org/10.5194/tc-14-2819-2020, https://doi.org/10.5194/tc-14-2819-2020, 2020
Short summary
Short summary
The mathematical formalism presented in this paper aims at simplifying computational strategies for tracking ice–ocean mass exchange in the Earth system. To this end, we define a set of generic, and quite simple, descriptions of evolving land, ocean and ice interfaces and present a unified method to compute the sea-level contribution of evolving ice sheets. The formalism can be applied to arbitrary geometries and at all timescales.
Stephen L. Cornford, Helene Seroussi, Xylar S. Asay-Davis, G. Hilmar Gudmundsson, Rob Arthern, Chris Borstad, Julia Christmann, Thiago Dias dos Santos, Johannes Feldmann, Daniel Goldberg, Matthew J. Hoffman, Angelika Humbert, Thomas Kleiner, Gunter Leguy, William H. Lipscomb, Nacho Merino, Gaël Durand, Mathieu Morlighem, David Pollard, Martin Rückamp, C. Rosie Williams, and Hongju Yu
The Cryosphere, 14, 2283–2301, https://doi.org/10.5194/tc-14-2283-2020, https://doi.org/10.5194/tc-14-2283-2020, 2020
Short summary
Short summary
We present the results of the third Marine Ice Sheet Intercomparison Project (MISMIP+). MISMIP+ is one in a series of exercises that test numerical models of ice sheet flow in simple situations. This particular exercise concentrates on the response of ice sheet models to the thinning of their floating ice shelves, which is of interest because numerical models are currently used to model the response to contemporary and near-future thinning in Antarctic ice shelves.
Alanna V. Alevropoulos-Borrill, Isabel J. Nias, Antony J. Payne, Nicholas R. Golledge, and Rory J. Bingham
The Cryosphere, 14, 1245–1258, https://doi.org/10.5194/tc-14-1245-2020, https://doi.org/10.5194/tc-14-1245-2020, 2020
Gong Cheng and Per Lötstedt
The Cryosphere, 14, 673–691, https://doi.org/10.5194/tc-14-673-2020, https://doi.org/10.5194/tc-14-673-2020, 2020
Short summary
Short summary
We present a time-dependent inverse method for ice sheet modeling. By investigating the sensitivity of the observations of the velocity and the height at the surface to the basal conditions of the ice, we show that if the basal parameters are time dependent, then time cannot be ignored in the inversion. By looking at the numerical features, we conclude that adding the height information of an ice sheet in the velocity inversion procedure could improve the robustness of the inference.
Xiaoran Guo, Liyun Zhao, Rupert M. Gladstone, Sainan Sun, and John C. Moore
The Cryosphere, 13, 3139–3153, https://doi.org/10.5194/tc-13-3139-2019, https://doi.org/10.5194/tc-13-3139-2019, 2019
Vincent Verjans, Amber A. Leeson, C. Max Stevens, Michael MacFerrin, Brice Noël, and Michiel R. van den Broeke
The Cryosphere, 13, 1819–1842, https://doi.org/10.5194/tc-13-1819-2019, https://doi.org/10.5194/tc-13-1819-2019, 2019
Short summary
Short summary
Firn models rely on empirical approaches for representing the percolation and refreezing of meltwater through the firn column. We develop liquid water schemes of different levels of complexity for firn models and compare their performances with respect to observations of density profiles from Greenland. Our results demonstrate that physically advanced water schemes do not lead to better agreement with density observations. Uncertainties in other processes contribute more to model discrepancy.
Leonardus van Kampenhout, Alan M. Rhoades, Adam R. Herrington, Colin M. Zarzycki, Jan T. M. Lenaerts, William J. Sacks, and Michiel R. van den Broeke
The Cryosphere, 13, 1547–1564, https://doi.org/10.5194/tc-13-1547-2019, https://doi.org/10.5194/tc-13-1547-2019, 2019
Short summary
Short summary
A new tool is evaluated in which the climate and surface mass balance (SMB) of the Greenland ice sheet are resolved at 55 and 28 km resolution, while the rest of the globe is modelled at ~110 km. The local refinement of resolution leads to improved accumulation (SMB > 0) compared to observations; however ablation (SMB < 0) is deteriorated in some regions. This is attributed to changes in cloud cover and a reduced effectiveness of a model-specific vertical downscaling technique.
Hélène Seroussi, Sophie Nowicki, Erika Simon, Ayako Abe-Ouchi, Torsten Albrecht, Julien Brondex, Stephen Cornford, Christophe Dumas, Fabien Gillet-Chaulet, Heiko Goelzer, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Thomas Kleiner, Eric Larour, Gunter Leguy, William H. Lipscomb, Daniel Lowry, Matthias Mengel, Mathieu Morlighem, Frank Pattyn, Anthony J. Payne, David Pollard, Stephen F. Price, Aurélien Quiquet, Thomas J. Reerink, Ronja Reese, Christian B. Rodehacke, Nicole-Jeanne Schlegel, Andrew Shepherd, Sainan Sun, Johannes Sutter, Jonas Van Breedam, Roderik S. W. van de Wal, Ricarda Winkelmann, and Tong Zhang
The Cryosphere, 13, 1441–1471, https://doi.org/10.5194/tc-13-1441-2019, https://doi.org/10.5194/tc-13-1441-2019, 2019
Short summary
Short summary
We compare a wide range of Antarctic ice sheet simulations with varying initialization techniques and model parameters to understand the role they play on the projected evolution of this ice sheet under simple scenarios. Results are improved compared to previous assessments and show that continued improvements in the representation of the floating ice around Antarctica are critical to reduce the uncertainty in the future ice sheet contribution to sea level rise.
Mathieu Morlighem, Michael Wood, Hélène Seroussi, Youngmin Choi, and Eric Rignot
The Cryosphere, 13, 723–734, https://doi.org/10.5194/tc-13-723-2019, https://doi.org/10.5194/tc-13-723-2019, 2019
Short summary
Short summary
Many glaciers along the coast of Greenland have been retreating. It has been suggested that this retreat is triggered by the presence of warm water in the fjords, and surface melt at the top of the ice sheet is exacerbating this problem. Here, we quantify the vulnerability of northwestern Greenland to further warming using a numerical model. We find that in current conditions, this sector alone will contribute more than 1 cm to sea rise level by 2100, and up to 3 cm in the most extreme scenario.
Sébastien Le clec'h, Sylvie Charbit, Aurélien Quiquet, Xavier Fettweis, Christophe Dumas, Masa Kageyama, Coraline Wyard, and Catherine Ritz
The Cryosphere, 13, 373–395, https://doi.org/10.5194/tc-13-373-2019, https://doi.org/10.5194/tc-13-373-2019, 2019
Short summary
Short summary
Quantifying the future contribution of the Greenland ice sheet (GrIS) to sea-level rise in response to atmospheric changes is important but remains challenging. For the first time a full representation of the feedbacks between a GrIS model and a regional atmospheric model was implemented. The authors highlight the fundamental need for representing the GrIS topography change feedbacks with respect to the atmospheric component face to the strong impact on the projected sea-level rise.
Julien Brondex, Fabien Gillet-Chaulet, and Olivier Gagliardini
The Cryosphere, 13, 177–195, https://doi.org/10.5194/tc-13-177-2019, https://doi.org/10.5194/tc-13-177-2019, 2019
Short summary
Short summary
Here, we apply a synthetic perturbation to the most active drainage basin of Antarctica and show that centennial mass loss projections obtained through ice flow models depend strongly on the implemented friction law, i.e. the mathematical relationship between basal drag and sliding velocities. In particular, the commonly used Weertman law considerably underestimates the sea-level contribution of this basin in comparison to two water pressure-dependent laws which rely on stronger physical bases.
Hongju Yu, Eric Rignot, Helene Seroussi, and Mathieu Morlighem
The Cryosphere, 12, 3861–3876, https://doi.org/10.5194/tc-12-3861-2018, https://doi.org/10.5194/tc-12-3861-2018, 2018
Short summary
Short summary
Thwaites Glacier, West Antarctica, has experienced rapid grounding line retreat and mass loss in the past decades. In this study, we simulate the evolution of Thwaites Glacier over the next century using different model configurations. Overall, we estimate a 5 mm contribution to global sea level rise from Thwaites Glacier in the next 30 years. However, a 300 % uncertainty is found over the next 100 years, ranging from 14 to 42 mm, depending on the model setup.
Youngmin Choi, Mathieu Morlighem, Michael Wood, and Johannes H. Bondzio
The Cryosphere, 12, 3735–3746, https://doi.org/10.5194/tc-12-3735-2018, https://doi.org/10.5194/tc-12-3735-2018, 2018
Short summary
Short summary
Calving is an important mechanism that controls the dynamics of Greenland outlet glaciers. We test and compare four calving laws and assess which calving law has better predictive abilities. Overall, the calving law based on von Mises stress is more satisfactory than other laws, but new parameterizations should be derived to better capture the detailed processes involved in calving.
Rupert M. Gladstone, Yuwei Xia, and John Moore
The Cryosphere, 12, 3605–3615, https://doi.org/10.5194/tc-12-3605-2018, https://doi.org/10.5194/tc-12-3605-2018, 2018
Short summary
Short summary
Computer models for the simulation of marine ice sheets (ice sheets resting on bedrock below sea level) historically show poor numerical convergence for grounding line (the boundary between grounded and floating parts of the ice sheet) movement. We have further characterised the nature of the numerical problems leading to poor convergence and highlighted implications for the design of computer experiments that test grounding line movement.
Hélène Seroussi and Mathieu Morlighem
The Cryosphere, 12, 3085–3096, https://doi.org/10.5194/tc-12-3085-2018, https://doi.org/10.5194/tc-12-3085-2018, 2018
Michael J. Wolovick and John C. Moore
The Cryosphere, 12, 2955–2967, https://doi.org/10.5194/tc-12-2955-2018, https://doi.org/10.5194/tc-12-2955-2018, 2018
Short summary
Short summary
In this paper, we explore the possibility of using locally targeted geoengineering to slow the rate of an ice sheet collapse. We find that an intervention as big as existing large civil engineering projects could have a 30 % probability of stopping an ice sheet collapse, while larger interventions have better odds of success. With more research to improve upon the simple designs we considered, it may be possible to perfect a design that was both achievable and had good odds of success.
Cited articles
Alley, R. B.: Fabrics in polar ice sheets: development and prediction,
Science, 240, 493–495, 1988.
Azuma, N., Wang, Y., Mori, K., Narita, H., Hondoh, T., Shoji, H., and
Watanabe, O.: Textures and fabrics in the Dome F (Antarctica) ice core,
Ann. Glaciol., 29, 163–168, 1999.
Bachmann, F., Hielscher, R., and Schaeben, H.: Grain detection from 2d and 3d
EBSD data – Specification of the MTEX algorithm, Ultramicroscopy, 111, 1720–1733, 2011.
Behn, M. D., Goldsby, D. L., and Hirth, G.: The role of grain size evolution in the rheology of ice: implications for reconciling laboratory creep data and the Glen flow law, The Cryosphere, 15, 4589–4605, https://doi.org/10.5194/tc-15-4589-2021, 2021.
Boneh, Y. and Skemer, P.: The effect of deformation history on the evolution
of olivine CPO, Earth Planet. Sc. Lett., 406, 213–222, 2014.
Bons, P. D., Koehn, D., and Jessell, M. W.: Microdynamic Simulation, Lecture
Notes in Earth Sciences 106, Springer, Berlin, 405 pp., 2008.
Bons, P. D., Kleiner, T., Llorens, M. G., Prior, D. J., Sachau, T., Weikusat,
I., and Jansen, D.: Greenland Ice Sheet: Higher nonlinearity of ice flow
significantly reduces estimated basal motion, Geophys. Res. Lett.,
45, 6542–6548, 2018.
Budd, W. and Jacka, T.: 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.
Budd, W. F., Warner, R. C., Jacka, T. H., Li, J., and Treverrow, A.: Ice flow
relations for stress and strain-rate components from combined shear and
compression laboratory experiments, J. Glaciol., 59, 374–392, 2013.
Castelnau, O., Shoji, H., Mangeney, A., Milsch, H., Duval, P., Miyamoto, A.,
Kawada, K., and Watanabe, O.: Anisotropic behavior of GRIP ices and flow in
central Greenland, Earth Planet. Sc. Lett., 154,
307–322, 1998.
Craw, L., Qi, C., Prior, D. J., Goldsby, D. L., and Kim, D.: Mechanics and
microstructure of deformed natural anisotropic ice, J. Struct. Geol., 115,
152–166, 2018.
Craw, L., Treverrow, A., Fan, S., Peternell, M., Cook, S., McCormack, F., and Roberts, J.: The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice, The Cryosphere, 15, 2235–2250, https://doi.org/10.5194/tc-15-2235-2021, 2021.
Cuffey, K. M. and Paterson, W. S. B.: The physics of glaciers, Academic Press, 4th Edn., ISBN 9780123694614, 2010.
Dahl-Jensen, D., Thorsteinsson, T., Alley, R., and Shoji, H.: Flow properties
of the ice from the Greenland Ice Core Project ice core: the reason for
folds?, J. Geophys. Res.-Oceans, 102, 26831–26840,
1997.
Di Leo, J. F., Walker, A. M., Li, Z. H., Wookey, J., Ribe, N. M., Kendall, J. M.,
and Tommasi, A.: Development of texture and seismic anisotropy during the
onset of subduction, Geochem. Geophy. Geosy., 15, 192–212, 2014.
Durand, G., Gillet-Chaulet, F., Svensson, A., Gagliardini, O., Kipfstuhl, S., Meyssonnier, J., Parrenin, F., Duval, P., and Dahl-Jensen, D.: Change in ice rheology during climate variations – implications for ice flow modelling and dating of the EPICA Dome C core, Clim. Past, 3, 155–167, https://doi.org/10.5194/cp-3-155-2007, 2007.
Duval, P. and Castelnau, O.: Dynamic recrystallization of ice in polar ice
sheets, J. Phys. IV, 5, 197–205, 1995.
Duval, P., Ashby, M. F., and Anderman, I.: Rate-controlling processes in the
creep of polycrystalline ice, J. Phys. Chem., 87,
4066–4074, 1983.
Edwards, T. L., Nowicki, S., Marzeion, B., Hock, R., Goelzer, H., Seroussi,
H., Jourdain, N. C., Slater, D. A., Turner, F. E., Smith, C. J., and McKenna,
C. M.: Projected land ice contributions to twenty-first-century sea level
rise, Nature, 593, 74–82, 2021.
ELLE International Consortium: ELLE Numerical Simulation Platform, https://git.code.sf.net/p/elle/gitelle-git (last access: 23 May 2022), 2018.
Fan, S., Hager, T. F., Prior, D. J., Cross, A. J., Goldsby, D. L., Qi, C., Negrini, M., and Wheeler, J.: Temperature and strain controls on ice deformation mechanisms: insights from the microstructures of samples deformed to progressively higher strains at −10, −20 and −30 ∘C, The Cryosphere, 14, 3875–3905, https://doi.org/10.5194/tc-14-3875-2020, 2020.
Fan, S., Cross, A. J., Prior, D. J., Goldsby, D. L., Hager, T. F., Negrini, M. and Qi, C.: Crystallographic Preferred Orientation (CPO) Development Governs Strain Weakening in Ice: Insights From High‐Temperature Deformation Experiments, J. Geophys. Res.-Sol. Ea., 126, e2021JB023173, https://doi.org/10.1029/2021JB023173, 2021.
Faria, S. H., Weikusat, I., and Azuma, N.: The microstructure of polar ice.
Part I: Highlights from ice core research, J. Struct. Geol., 61, 2–20,
https://doi.org/10.1016/j.jsg.2013.09.010, 2014.
Gerbi, C., Mills, S., Clavette, R., Campbell, S., Bernsen, S.,
Clemens-Sewall, D., Lee, I., Hawley, R., Kreutz, K., and Hruby, K.
Microstructures in a shear margin: Jarvis Glacier, Alaska, J.
Glaciol., 67, 1163–1176, 2021.
Golledge, N. R., Kowalewski, D. E., Naish, T. R., Levy, R. H., Fogwill, C.
J., and Gasson, E. G. W.: The multi-millennial Antarctic commitment to future
sea-level rise, Nature, 526, 421–425, https://doi.org/10.1038/nature15706, 2015.
Griera, A., Llorens, M. G., Gomez-Rivas, E., Bons, P. D., Jessell, M. W.,
Evans, L. A., and Lebensohn, R.: Numerical modelling of porphyroclast and
porphyroblast rotation in anisotropic rocks, Tectonophysics, 587, 4–29,
2013.
Gomez-Rivas, E., Griera, A., Llorens, M. G., Bons, P. D., Lebensohn, R. A., and
Piazolo, S.: Subgrain rotation recrystallization during shearing: insights
from full-field numerical simulations of halite polycrystals, J.
Geophys. Res.-Sol. Ea., 122, 8810–8827, 2017.
Gow, A. J., Meese, D. A., Alley, R. B., Fitzpatrick, J. J., Anandakrishnan, S.,
Woods, G. A., and Elder, B. C.: Physical and structural properties of the
Greenland Ice Sheet Project 2 ice core: A review, J. Geophys. Res.-Oceans, 102, 26559–26575,
1997.
Haefeli, R.: Contribution to the movement and the form of ice sheets in the
Arctic and Antarctic, J. Glaciol., 3, 1133–1151, 1961.
Hudleston, P. J.: Similar folds, recumbent folds, and gravity tectonics in ice and rocks, J. Geol., 85, 113–122, 1977.
Hudleston, P. J.: Structures and fabrics in glacial ice: a review, J.
Struct. Geol., 81, 1–27, 2015.
Jacka, T. H. and Maccagnan, M.: Ice crystallographic and strain rate changes
with strain in compression and extension, Cold Reg. Sci. Technol., 8, 269–286, 1984.
Jacka, T. H. and Li, J.: Flow rates and crystal orientation fabrics in compression of polycrystalline ice at low temperatures and stresses, in: International Symposium on Physics of Ice Core Records, edited by: Hondoh, T., Shikotsukohan, Hokkaido, Japan, 14–17 September 1998, 83–102, 2000.
Jackson, M. and Kamb, B.: The marginal shear stress of Ice Stream B, West
Antarctica, J. Glaciol., 43, 415–426, 1997.
Jansen, D., Llorens, M.-G., Westhoff, J., Steinbach, F., Kipfstuhl, S., Bons, P. D., Griera, A., and Weikusat, I.: Small-scale disturbances in the stratigraphy of the NEEM ice core: observations and numerical model simulations, The Cryosphere, 10, 359–370, https://doi.org/10.5194/tc-10-359-2016, 2016.
Jennings, S. J. A. and Hambrey, M. J.: Structures and deformation in
glaciers and ice sheets, Rev. Geophys., 59, e2021RG000743, https://doi.org/10.1029/2021RG000743, 2021.
Joughin, I. A. N., Smith, B. E., and Howat, I. M.: A complete map of Greenland ice
velocity derived from satellite data collected over 20 years, J.
Glaciol., 64, 1–11, 2018.
Journaux, B., Chauve, T., Montagnat, M., Tommasi, A., Barou, F., Mainprice, D., and Gest, L.: Recrystallization processes, microstructure and crystallographic preferred orientation evolution in polycrystalline ice during high-temperature simple shear, The Cryosphere, 13, 1495–1511, https://doi.org/10.5194/tc-13-1495-2019, 2019.
Jun, L. and Jacka, T. H.: Horizontal shear rate of ice initially exhibiting
vertical compression fabrics, J. Glaciol., 44, 670–672,
1998.
Kamb, W. B.: Experimental recrystallization of ice under stress, in: Flow and Fracture of Rocks, edited by: Heard, H. C., Borg, I. Y., Carter, N. L., and Rayleigh, C. B., American Geophysical Union, 211–242, 1972.
Kaminski, E., Ribe, N. M., and Browaeys, J. T.: D-Rex, a program for calculation
of seismic anisotropy due to crystal lattice preferred orientation in the
convective upper mantle, Geophys. J. Int., 158,
744-752, 2004.
Katayama, I. and Karato, S. I.: Effect of temperature on the B-to C-type
olivine fabric transition and implication for flow pattern in subduction
zones, Phys. Earth Planet. Int., 157, 33–45,
2006.
Kim, D., Prior, D. J., Han, Y., Qi, C., Han, H., and Ju, H. T.: Microstructures
and Fabric Transitions of Natural Ice from the Styx Glacier, Northern
Victoria Land, Antarctica, Minerals, 10, 892, https://doi.org/10.3390/min10100892, 2020.
Lebensohn, R. A. and Rollett, A. D.: Spectral methods for full-field
micromechanical modelling of polycrystalline materials, Comput.
Mater. Sci., 173, 109336, https://doi.org/10.1016/j.commatsci.2019.109336, 2020.
Li, Z. H., Di Leo, J. F., and Ribe, N. M.: Subduction-induced mantle flow,
finite strain, and seismic anisotropy: Numerical modeling, J.
Geophys. Res.-Sol. Ea., 119, 5052–5076, 2014.
Lipenkov, V. Y., Barkov, N. I., Duval, P. and Pimienta, P.: Crystalline texture of the 2083 m ice core at Vostok Station, Antarctica, J. Glaciol., 35, 392–398, 1989.
Llorens, M. G., Griera, A., Bons, P. D., Roessiger, J., Lebensohn, R.,
Evans, L., and Weikusat, I. Dynamic recrystallisation of ice aggregates
during co-axial viscoplastic deformation: a numerical approach, J.
Glaciol., 62, 359–377, 2016a.
Llorens, M. G., Griera, A., Bons, P. D., Lebensohn, R. A., Evans, L. A.,
Jansen, D., and Weikusat, I.: Full field predictions of ice dynamic
recrystallisation under simple shear conditions, Earth Planet. Sc.
Lett., 450, 233–242, 2016b.
Llorens, M. G., Griera, A., Steinbach, F., Bons, P. D., Gomez-Rivas, E.,
Jansen, D., Roessiger, J., Lebensohn, R. A., and Weikusat, I.: Dynamic
recrystallization during deformation of polycrystalline ice: insights from
numerical simulations, Philos. T. R. Soc. A, 375, 20150346, https://doi.org/10.1098/rsta.2015.0346, 2017.
Llorens, M. G., Griera, A., Bons, P. D., Gomez-Rivas, E., Weikusat, I., Prior,
D. J., Kerch, J., and Lebensohn, R. A.: Seismic anisotropy of temperate ice in
polar ice sheets, J. Geophys. Res.-Earth, 125, e2020JF005714, https://doi.org/10.1029/2020JF005714, 2020.
Llorens, M.-G., Griera, A., Bons, P. D., Weikusat, I., Prior, D. J., Gómez-Rivas, E., de Riese, T., Jimenez-Munt, I., García-Castellanos, D., and Lebensohn, R. A.: Full-field numerical simulations of ice
viscoplastic deformation during two deformation events, DIGITAL.CSIC [data set], https://doi.org/10.20350/digitalCSIC/14643, 2022.
LeDoux, C. M., Hulbe, C. L., Forbes, M. P., Scambos, T. A., and Alley, K.:
Structural provinces of the ross ice shelf, antarctica, Ann.
Glaciol., 58, 88–98, 2017.
Lilien, D. A., Rathmann, N. M., Hvidberg, C. S., and Dahl-Jensen, D.: Modeling
Ice-Crystal Fabric as a Proxy for Ice-Stream Stability, J.
Geophys. Res.-Earth, 126, e2021JF006306, https://doi.org/10.1029/2021JF006306, 2021.
Lipenkov, V. Y., Barkov, N. I., Duval, P., and Pimienta, P.: Crystalline Texture
of the 2083 m Ice Core at Vostok Station, Antarctica, J. Glaciol., 35,
392–398, 1989.
Llorens, M.-G., Griera, A., Bons, P. D., Weikusat, I., Prior, D. J., Gómez-Rivas, E., de Riese, T., Jimenez-Munt, I., García-Castellanos, D., and Lebensohn, R. A.: Full-field numerical simulations of ice viscoplastic deformation during two deformation events, DIGITAL.CSIC [data set], https://doi.org/10.20350/digitalCSIC/14643, 2022.
Lutz, F., Eccles, J., Prior, D. J., Craw, L., Fan, S., Hulbe, C., Forbes, M.,
Still, H., Pyne, A., and Mandeno, D.: Constraining Ice Shelf Anisotropy Using
Shear Wave Splitting Measurements from Active-Source Borehole Seismics,
J. Geophys. Res.-Earth, 125, e2020JF005707, https://doi.org/10.1029/2020JF005707,
2020.
Lutz, F., Prior, D. J., Still, H., Bowman, M. H., Boucinhas, B., Craw, L., Fan, S., Kim, D., Mulvaney, R., Thomas, R. E., and Hulbe, C. L.: Ultrasonic and seismic constraints on crystallographic preferred orientations of the Priestley Glacier shear margin, Antarctica, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2021-382, in review, 2022.
Millstein, J., Minchew, B., and Pegler, S. S.: Reassessing the flow law of
glacier ice using satellite observations, Commun. Earth Environ., 3, 1–7, https://doi.org/10.31223/X5D32X, 2021.
Montagnat, M., Blackford, J. R., Piazolo, S., Arnaud, L., and Lebensohn, R. A.:
Measurements and full-field predictions of deformation heterogeneities in
ice, Earth Planet. Sc. Lett., 305, 153–160, https://doi.org/10.1016/j.epsl.2011.02.050, 2011.
Montagnat, M., Buiron, D., Arnaud, L., Broquet, A., Schlitz, P., Jacob, R.,
and Kipfstuhl, S.: Measurements and numerical simulation of fabric evolution
along the Talos Dome ice core, Antarctica, Earth Planet. Sc. Lett., 357, 168–178, 2012.
Montagnat, M., Azuma, N., Dahl-Jensen, D., Eichler, J., Fujita, S., Gillet-Chaulet, F., Kipfstuhl, S., Samyn, D., Svensson, A., and Weikusat, I.: Fabric along the NEEM ice core, Greenland, and its comparison with GRIP and NGRIP ice cores, The Cryosphere, 8, 1129–1138, https://doi.org/10.5194/tc-8-1129-2014, 2014a.
Montagnat, M., Castelnau, O., Bons, P. D., Faria, S. H., Gagliardini, O.,
Gillet-Chaulet, F., Grennerat, F., Griera, A., Lebensohn, R. A., Moulinec,
H., Roessiger, J., and Suquet, P.: Multiscale modeling of ice deformation
behavior, J. Struct. Geol., 61, 78–108,
https://doi.org/10.1016/j.jsg.2013.05.002, 2014b.
Montagnat, M., Chauve, T., Barou, F., Tommasi, A., Beausir, B., and
Frassengeas, C.: Analysis of dynamic recrystallisation of ice from EBSD
orientation mapping, Front. Earth Sci., 3, 13, https://doi.org/10.3389/feart.2015.00081, 2015.
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.
Nerem, R. S., Beckley, B. D., Fasullo, J. T., Hamlington, B. D., Masters, D., and
Mitchum, G. T.: Climate-change–driven accelerated sea-level rise detected in
the altimeter era, P. Natl. Acad. Sci. USA, 115,
2022–2025, 2018.
Passchier, C. W.: Reconstruction of deformation and flow parameters from
deformed vein sets, Tectonophysics, 180, 185–199, 1990.
Peternell, M. and Wilson, C. J.: Effect of strain rate cycling on
microstructures and crystallographic preferred orientation during
high-temperature creep, Geology, 44, 279–282, 2016.
Piazolo, S., Bons, P. D., Griera, A., Llorens, M. G., Gomez-Rivas, E., Koehn,
D., Wheeler, J., Gardner, R., Godinho, J. R., Evans, L., and Lebensohn, R. A.: A
review of numerical modelling of the dynamics of microstructural development
in rocks and ice: Past, present and future, J. Struct. Geol.,
125, 111–123, 2019.
Qi, C., Goldsby, D. L., and Prior, D. J.: The down-stress transition from
cluster to cone fabrics in experimentally deformed ice, Earth Planet.
Sc. Lett., 471, 136–147, 2017.
Qi, C., Prior, D. J., Craw, L., Fan, S., Llorens, M.-G., Griera, A., Negrini, M., Bons, P. D., and Goldsby, D. L.: Crystallographic preferred orientations of ice deformed in direct-shear experiments at low temperatures, The Cryosphere, 13, 351–371, https://doi.org/10.5194/tc-13-351-2019, 2019.
Richards, D. H., Pegler, S. S., Piazolo, S., and Harlen, O. G.: The evolution of
ice fabrics: A continuum modelling approach validated against laboratory
experiments, Earth Planet. Sc. Lett., 556, 116718, https://doi.org/10.1016/j.epsl.2020.116718, 2021.
Skemer, P., Katayama, I., Jiang, Z., and Karato, S. I.: The misorientation
index: Development of a new method for calculating the strength of
lattice-preferred orientation, Tectonophysics, 411, 157–167, 2005.
Smith, E. C., Baird, A. F., Kendall, J. M., Martín, C., White, R. S., Brisbourne, A. M., and Smith, A. M.: Ice fabric in an Antarctic ice stream interpreted from seismic anisotropy, Geophys. Res. Lett., 44, 3710–3718, 2017.
Steinbach, F., Bons, P. D., Griera, A., Jansen, D., Llorens, M.-G., Roessiger, J., and Weikusat, I.: Strain localization and dynamic recrystallization in the ice–air aggregate: a numerical study, The Cryosphere, 10, 3071–3089, https://doi.org/10.5194/tc-10-3071-2016, 2016.
Thomas, R. E., Negrini, M., Prior, D. J., Mulvaney, R., Still, H., Bowman,
M. H., Craw, L., Fan, S., Hubbard, B., Hulbe, C., Kim, D., and Lutz, F.:
Microstructure and Crystallographic Preferred Orientations of an Azimuthally
Oriented Ice Core from a Lateral Shear Margin: Priestley Glacier,
Antarctica, Front. Earth Sci., 9, 1084, https://doi.org/10.3389/feart.2021.702213, 2021.
Thorsteinsson, T., Kipfstuhl, J., and Miller, H.: Textures and fabrics in the
GRIP ice core, J. Geophys. Res.-Ocean, 102, 26583–26599, 1997.
Thorsteinsson, T., Waddington, E. D., and Fletcher, R. C.: Spatial and temporal
scales of anisotropic effects in ice-sheet flow, Ann. Glaciol., 37, 40–48, 2003.
Treverrow, A., Budd, W. F., Jacka, T. H., amd Warner, R. C.: The tertiary creep of
polycrystalline ice: experimental evidence for stress dependent levels of
strain rate enhancement, J. Glaciol., 58, 301–314, https://doi.org/10.3189/2012JoG11J149, 2012.
Vaughan, M. J., Prior, D. J., Jefferd, M., Brantut, N., Mitchell, T. M., and
Seidemann, M.: Insights into anisotropy development and weakening of ice from
in situ P wave velocity monitoring during laboratory creep, J.
Geophys. Res.-Sol. Ea., 122, 7076–7089, 2017.
Voigt, D. E.: c-Axis Fabric of the South Pole Ice Core, SPC14, U.S. Antarctic
Program (USAP) Data Center [data set], https://doi.org/10.15784/601057, 2017.
Vollmer, F. W.: An application of eigenvalue methods to structural domain
analysis, Geol. Soc. Am. Bull., 102, 786–791, 1990.
Young, N. W. and Hyland, G.: Velocity and strain rates derived from InSAR
analysis over the Amery Ice Shelf, East Antarctica, Ann. Glaciol.,
34, 228–234, 2002.
Wang, Y., Thorsteinsson, T., Kipfstuhl, J., Miller, H., Dahl-Jensen, D., and Shoji, H.: A vertical girdle fabric in the NorthGRIP deep ice core, North Greenland, Ann. Glaciol., 35, 515–520, https://doi.org/10.3189/172756402781817301, 2002.
Weikusat, I., Jansen, D., Binder, T., Eichler, J., Faria, S. H., Wilhelms,
F., Kipfstuhl, S., Sheldon, S., Miller, H., Dahl-Jensen, D., and Kleiner, T.:
Physical analysis of an Antarctic ice core – towards an integration of
micro-and macrodynamics of polar ice, Philos. T.
R. Soc. A, 375, 20150347, https://doi.org/10.1098/rsta.2015.0347, 2017.
Wilson, C. J., Peternell, M., Hunter, N. J., and Luzin, V.: Deformation of
polycrystalline D2O ice: Its sensitivity to temperature and strain-rate as
an analogue for terrestrial ice, Earth Planet. Sc. Lett., 532,
115999, https://doi.org/10.1016/j.epsl.2019.115999, 2020.
Wilson, C. J. L.: Fabrics in polycrystalline ice deformed experimentally at
−108 ∘C, Cold Reg. Sci. Technol., 6, 149–161, 1982.
Wilson, C. J. L. and Peternell, M. A.: Ice deformed in compression and simple
shear: control of temperature and initial fabric, J. Glaciol., 58, 11–22, 2012.
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.
Polar ice is formed by ice crystals, which form fabrics that are utilised to interpret how ice...