Articles | Volume 15, issue 12
https://doi.org/10.5194/tc-15-5675-2021
© 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-15-5675-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Dec 2021
Research article |
| 17 Dec 2021
| 17 Dec 2021
Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow
Anna Derkacheva
CORRESPONDING AUTHOR
Institute of Environmental Geosciences, Université Grenoble Alpes, CNRS, IRD, INP, 38400 Grenoble, Isère, France
Fabien Gillet-Chaulet
Institute of Environmental Geosciences, Université Grenoble Alpes, CNRS, IRD, INP, 38400 Grenoble, Isère, France
Jeremie Mouginot
Institute of Environmental Geosciences, Université Grenoble Alpes, CNRS, IRD, INP, 38400 Grenoble, Isère, France
Department of Earth System Science, University of California, Irvine, 92697 CA, USA
Eliot Jager
Institute of Environmental Geosciences, Université Grenoble Alpes, CNRS, IRD, INP, 38400 Grenoble, Isère, France
Nathan Maier
Institute of Environmental Geosciences, Université Grenoble Alpes, CNRS, IRD, INP, 38400 Grenoble, Isère, France
Samuel Cook
Institute of Environmental Geosciences, Université Grenoble Alpes, CNRS, IRD, INP, 38400 Grenoble, Isère, France
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Samuel J. Cook, Poul Christoffersen, Joe Todd, Donald Slater, and Nolwenn Chauché
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The Cryosphere, 13, 2673–2691, https://doi.org/10.5194/tc-13-2673-2019, https://doi.org/10.5194/tc-13-2673-2019, 2019
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Lionel Favier, Nicolas C. Jourdain, Adrian Jenkins, Nacho Merino, Gaël Durand, Olivier Gagliardini, Fabien Gillet-Chaulet, and Pierre Mathiot
Geosci. Model Dev., 12, 2255–2283, https://doi.org/10.5194/gmd-12-2255-2019, https://doi.org/10.5194/gmd-12-2255-2019, 2019
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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
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Denis Cohen, Fabien Gillet-Chaulet, Wilfried Haeberli, Horst Machguth, and Urs H. Fischer
The Cryosphere, 12, 2515–2544, https://doi.org/10.5194/tc-12-2515-2018, https://doi.org/10.5194/tc-12-2515-2018, 2018
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Olivier Passalacqua, Marie Cavitte, Olivier Gagliardini, Fabien Gillet-Chaulet, Frédéric Parrenin, Catherine Ritz, and Duncan Young
The Cryosphere, 12, 2167–2174, https://doi.org/10.5194/tc-12-2167-2018, https://doi.org/10.5194/tc-12-2167-2018, 2018
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Heiko Goelzer, Sophie Nowicki, Tamsin Edwards, Matthew Beckley, Ayako Abe-Ouchi, Andy Aschwanden, Reinhard Calov, Olivier Gagliardini, Fabien Gillet-Chaulet, Nicholas R. Golledge, Jonathan Gregory, Ralf Greve, Angelika Humbert, Philippe Huybrechts, Joseph H. Kennedy, Eric Larour, William H. Lipscomb, Sébastien Le clec'h, Victoria Lee, Mathieu Morlighem, Frank Pattyn, Antony J. Payne, Christian Rodehacke, Martin Rückamp, Fuyuki Saito, Nicole Schlegel, Helene Seroussi, Andrew Shepherd, Sainan Sun, Roderik van de Wal, and Florian A. Ziemen
The Cryosphere, 12, 1433–1460, https://doi.org/10.5194/tc-12-1433-2018, https://doi.org/10.5194/tc-12-1433-2018, 2018
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We have compared a wide spectrum of different initialisation techniques used in the ice sheet modelling community to define the modelled present-day Greenland ice sheet state as a starting point for physically based future-sea-level-change projections. Compared to earlier community-wide comparisons, we find better agreement across different models, which implies overall improvement of our understanding of what is needed to produce such initial states.
Johannes Jakob Fürst, Fabien Gillet-Chaulet, Toby J. Benham, Julian A. Dowdeswell, Mariusz Grabiec, Francisco Navarro, Rickard Pettersson, Geir Moholdt, Christopher Nuth, Björn Sass, Kjetil Aas, Xavier Fettweis, Charlotte Lang, Thorsten Seehaus, and Matthias Braun
The Cryosphere, 11, 2003–2032, https://doi.org/10.5194/tc-11-2003-2017, https://doi.org/10.5194/tc-11-2003-2017, 2017
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For the large majority of glaciers and ice caps, there is no information on the thickness of the ice cover. Any attempt to predict glacier demise under climatic warming and to estimate the future contribution to sea-level rise is limited as long as the glacier thickness is not well constrained. Here, we present a two-step mass-conservation approach for mapping ice thickness. Measurements are naturally reproduced. The reliability is readily assessible from a complementary map of error estimates.
O. Gagliardini, J. Brondex, F. Gillet-Chaulet, L. Tavard, V. Peyaud, and G. Durand
The Cryosphere, 10, 307–312, https://doi.org/10.5194/tc-10-307-2016, https://doi.org/10.5194/tc-10-307-2016, 2016
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In this paper it is shown that the sensitivity to the mesh resolution is not
improved for a vanishing friction at the grounding line (GL). For a discontinuous friction at the GL, we further show that the results are moreover very sensitive to the way the friction is interpolated in the close vicinity of the GL. In the light of these new insights, new results for the MISMIP3d experiments obtained for higher resolutions than previously published are made available for future comparisons.
T. L. Edwards, X. Fettweis, O. Gagliardini, F. Gillet-Chaulet, H. Goelzer, J. M. Gregory, M. Hoffman, P. Huybrechts, A. J. Payne, M. Perego, S. Price, A. Quiquet, and C. Ritz
The Cryosphere, 8, 181–194, https://doi.org/10.5194/tc-8-181-2014, https://doi.org/10.5194/tc-8-181-2014, 2014
T. L. Edwards, X. Fettweis, O. Gagliardini, F. Gillet-Chaulet, H. Goelzer, J. M. Gregory, M. Hoffman, P. Huybrechts, A. J. Payne, M. Perego, S. Price, A. Quiquet, and C. Ritz
The Cryosphere, 8, 195–208, https://doi.org/10.5194/tc-8-195-2014, https://doi.org/10.5194/tc-8-195-2014, 2014
F. Gillet-Chaulet, O. Gagliardini, H. Seddik, M. Nodet, G. Durand, C. Ritz, T. Zwinger, R. Greve, and D. G. Vaughan
The Cryosphere, 6, 1561–1576, https://doi.org/10.5194/tc-6-1561-2012, https://doi.org/10.5194/tc-6-1561-2012, 2012
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The Cryosphere, 18, 2939–2968, https://doi.org/10.5194/tc-18-2939-2024, https://doi.org/10.5194/tc-18-2939-2024, 2024
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We explore the interplay between surface runoff and subglacial conditions. We focus on Kongsvegen glacier in Svalbard. We drilled 350 m down to the glacier base to measure water pressure, till strength, seismic noise, and glacier surface velocity. In the low-melt season, the drainage system adapted gradually, while the high-melt season led to a transient response, exceeding drainage capacity and enhancing sliding. Our findings contribute to discussions on subglacial hydro-mechanical processes.
Alexander H. Jarosch, Eyjólfur Magnússon, Krista Hannesdóttir, Joaquín M. C. Belart, and Finnur Pálsson
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Geothermally active regions beneath glaciers not only influence local ice flow as well as the mass balance of glaciers but also control changes of subglacial water reservoirs and possible subsequent glacier lake outburst floods. In Iceland, such outburst floods impose danger to people and infrastructure and are therefore monitored. We present a novel computer-simulation-supported method to estimate the activity of such geothermal areas and to monitor its evolution.
Weiyang Bao and Carlos Moffat
The Cryosphere, 18, 187–203, https://doi.org/10.5194/tc-18-187-2024, https://doi.org/10.5194/tc-18-187-2024, 2024
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A shallow sill can promote the downward transport of the upper-layer freshwater outflow in proglacial fjords. This sill-driven transport reduces fjord temperature and stratification. The sill depth, freshwater discharge, fjord temperature, and stratification are key parameters that modulate the heat supply towards glaciers. Additionally, the relative depth of the plume outflow, the fjord, and the sill can be used to characterize distinct circulation and heat transport regimes in glacial fjords.
Marion A. McKenzie, Lauren E. Miller, Jacob S. Slawson, Emma J. MacKie, and Shujie Wang
The Cryosphere, 17, 2477–2486, https://doi.org/10.5194/tc-17-2477-2023, https://doi.org/10.5194/tc-17-2477-2023, 2023
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Topographic highs (“bumps”) across glaciated landscapes have the potential to affect glacial ice. Bumps in the deglaciated Puget Lowland are assessed for streamlined glacial features to provide insight on ice–bed interactions. We identify a general threshold in which bumps significantly disrupt ice flow and sedimentary processes in this location. However, not all bumps have the same degree of impact. The system assessed here has relevance to parts of the Greenland Ice Sheet and Thwaites Glacier.
Camilo Andrés Rada Giacaman and Christian Schoof
The Cryosphere, 17, 761–787, https://doi.org/10.5194/tc-17-761-2023, https://doi.org/10.5194/tc-17-761-2023, 2023
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Water flowing at the base of glaciers plays a crucial role in controlling the speed at which glaciers move and how glaciers react to climate. The processes happening below the glaciers are extremely hard to observe and remain only partially understood. Here we provide novel insight into the subglacial environment based on an extensive dataset with over 300 boreholes on an alpine glacier in the Yukon Territory. We highlight the importance of hydraulically disconnected regions of the glacier bed.
Alexander O. Hager, Matthew J. Hoffman, Stephen F. Price, and Dustin M. Schroeder
The Cryosphere, 16, 3575–3599, https://doi.org/10.5194/tc-16-3575-2022, https://doi.org/10.5194/tc-16-3575-2022, 2022
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The presence of water beneath glaciers is a control on glacier speed and ocean-caused melting, yet it has been unclear whether sizable volumes of water can exist beneath Antarctic glaciers or how this water may flow along the glacier bed. We use computer simulations, supported by observations, to show that enough water exists at the base of Thwaites Glacier, Antarctica, to form "rivers" beneath the glacier. These rivers likely moderate glacier speed and may influence its rate of retreat.
Amy Jenson, Jason M. Amundson, Jonathan Kingslake, and Eran Hood
The Cryosphere, 16, 333–347, https://doi.org/10.5194/tc-16-333-2022, https://doi.org/10.5194/tc-16-333-2022, 2022
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Outburst floods are sudden releases of water from glacial environments. As glaciers retreat, changes in glacier and basin geometry impact outburst flood characteristics. We combine a glacier flow model describing glacier retreat with an outburst flood model to explore how ice dam height, glacier length, and remnant ice in a basin influence outburst floods. We find storage capacity is the greatest indicator of flood magnitude, and the flood onset mechanism is a significant indicator of duration.
Andrew O. Hoffman, Knut Christianson, Daniel Shapero, Benjamin E. Smith, and Ian Joughin
The Cryosphere, 14, 4603–4609, https://doi.org/10.5194/tc-14-4603-2020, https://doi.org/10.5194/tc-14-4603-2020, 2020
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The West Antarctic Ice Sheet has long been considered geometrically prone to collapse, and Thwaites Glacier, the largest glacier in the Amundsen Sea, is likely in the early stages of disintegration. Using observations of Thwaites Glacier velocity and elevation change, we show that the transport of ~2 km3 of water beneath Thwaites Glacier has only a small and transient effect on glacier speed relative to ongoing thinning driven by ocean melt.
Andreas Alexander, Jaroslav Obu, Thomas V. Schuler, Andreas Kääb, and Hanne H. Christiansen
The Cryosphere, 14, 4217–4231, https://doi.org/10.5194/tc-14-4217-2020, https://doi.org/10.5194/tc-14-4217-2020, 2020
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In this study we present subglacial air, ice and sediment temperatures from within the basal drainage systems of two cold-based glaciers on Svalbard during late spring and the summer melt season. We put the data into the context of air temperature and rainfall at the glacier surface and show the importance of surface events on the subglacial thermal regime and erosion around basal drainage channels. Observed vertical erosion rates thereby reachup to 0.9 m d−1.
Ugo Nanni, Florent Gimbert, Christian Vincent, Dominik Gräff, Fabian Walter, Luc Piard, and Luc Moreau
The Cryosphere, 14, 1475–1496, https://doi.org/10.5194/tc-14-1475-2020, https://doi.org/10.5194/tc-14-1475-2020, 2020
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Our study addresses key questions on the subglacial drainage system physics through a novel observational approach that overcomes traditional limitations. We conducted, over 2 years, measurements of the subglacial water-flow-induced seismic noise and of glacier basal sliding speeds. We then inverted for the subglacial channel's hydraulic pressure gradient and hydraulic radius and investigated the links between the equilibrium state of subglacial channels and glacier basal sliding.
Fabian Lindner, Fabian Walter, Gabi Laske, and Florent Gimbert
The Cryosphere, 14, 287–308, https://doi.org/10.5194/tc-14-287-2020, https://doi.org/10.5194/tc-14-287-2020, 2020
Edyta Łokas, Agata Zaborska, Ireneusz Sobota, Paweł Gaca, J. Andrew Milton, Paweł Kocurek, and Anna Cwanek
The Cryosphere, 13, 2075–2086, https://doi.org/10.5194/tc-13-2075-2019, https://doi.org/10.5194/tc-13-2075-2019, 2019
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Cryoconite granules built of mineral particles, organic substances and living organisms significantly influence fluxes of energy and matter at glacier surfaces. They contribute to ice melting, give rise to an exceptional ecosystem, and effectively trap contaminants. This study evaluates contamination levels of radionuclides in cryoconite from Arctic glaciers and identifies sources of this contamination, proving that cryoconite is an excellent indicator of atmospheric contamination.
Benedict T. I. Reinardy, Adam D. Booth, Anna L. C. Hughes, Clare M. Boston, Henning Åkesson, Jostein Bakke, Atle Nesje, Rianne H. Giesen, and Danni M. Pearce
The Cryosphere, 13, 827–843, https://doi.org/10.5194/tc-13-827-2019, https://doi.org/10.5194/tc-13-827-2019, 2019
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Cold-ice processes may be widespread within temperate glacier systems but the role of cold-ice processes in temperate glacier systems is relatively unknown. Climate forcing is the main control on glacier mass balance but potential for heterogeneous thermal conditions at temperate glaciers calls for improved model assessments of future evolution of thermal conditions and impacts on glacier dynamics and mass balance. Cold-ice processes need to be included in temperate glacier land system models.
Cited articles
Ahlstrøm, A. P., Petersen, D., Langen, P. L., Citterio, M., and Box, J. E.: Abrupt shift in the observed runoff from the southwestern Greenland ice
sheet, Sci. Adv., 3, 1–8, https://doi.org/10.1126/sciadv.1701169, 2017. a
Altena, B. and Kääb, A.: Weekly glacier flow estimation from dense
satellite time series using adapted optical flow technology, Front. Earth Sci., 5, 1–12, https://doi.org/10.3389/feart.2017.00053, 2017. a
Arthern, R. J. and Gudmundsson, G. H.: Initialization of ice-sheet forecasts
viewed as an inverse Robin problem, J. Glaciol., 56, 527–533,
https://doi.org/10.3189/002214310792447699, 2010. a, b
Arthern, R. J., Hindmarsh, R. C. A., and Williams, C. R.: Flow speed within
the Antarctic ice sheet and its controls inferred from satellite observations, J. Geophys. Res.-Earth, 120, 1171–1188, https://doi.org/10.1002/2014JF003239, 2015. a
Bartholomew, I., Nienow, P., Mair, D., Hubbard, A., King, M. A., and Sole, A.: Seasonal evolution of subglacial drainage and acceleration in a Greenland
outlet glacier, Nat. Geosci., 3, 408–411, https://doi.org/10.1038/ngeo863, 2010. a, b, c
Bartholomew, I., Nienow, P., Sole, A., Mair, D., Cowton, T., and King, M. A.:
Short-term variability in Greenland Ice Sheet motion forced by time-varying
meltwater drainage: Implications for the relationship between subglacial
drainage system behavior and ice velocity, J. Geophys. Res.-Earth, 117, 1–17, https://doi.org/10.1029/2011JF002220, 2012. a
Booth, A. D., Clark, R. A., Kulessa, B., Murray, T., Carter, J., Doyle, S., and Hubbard, A.: Thin-layer effects in glaciological seismic
amplitude-versus-angle (AVA) analysis: implications for characterising a
subglacial till unit, Russell Glacier, West Greenland, The Cryosphere, 6,
909–922, https://doi.org/10.5194/tc-6-909-2012, 2012. a
Bougamont, M., Christoffersen, P., Hubbard, A. L., Fitzpatrick, A. A., Doyle,
S. H., and Carter, S. P.:Sensitive response of the Greenland Ice Sheet to
surface melt drainage over a soft bed, Nat. Commun., 5, 5052, https://doi.org/10.1038/ncomms6052, 2014. a, b, c, d
Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821–839, https://doi.org/10.5194/tc-6-821-2012, 2012. a
Brinkerhoff, D., Aschwanden, A., and Fahnestock, M.: Constraining subglacial
processes from surface velocity observations using surrogate-based Bayesian
inference, J. Glaciol., 67, 385–403, https://doi.org/10.1017/jog.2020.112, 2021. a, b
Budd, W. F., Keage, P., and Blundy, N.: Empirical study of ice sliding, J. Glaciol., 2, 157–170, https://doi.org/10.3189/S0022143000029804, 1979. a
Budd, W. F., Jenssen, D., and Smith, I. N.: A Three-Dimensional Time-Dependent Model of the West Antarctic Ice Sheet, Ann. Glaciol., 5, 29–36, https://doi.org/10.3189/1984AoG5-1-29-36, 1984. a
Cabral, B. and Leedom, L. C.: Imaging Vector Fields Using Line Integral
Convolution, in: Proceedings of ACM SIGGRAPH'93, Anaheim, 263–270, https://doi.org/10.1145/166117.166151, 1993. a
Christoffersen, P., Bougamont, M., Hubbard, A., Doyle, S. H., Grigsby, S., and Pettersson, R.: Cascading lake drainage on the Greenland Ice Sheet triggered by tensile shock and fracture, Nat. Commun., 9, 1064,
https://doi.org/10.1038/s41467-018-03420-8, 2018. a, b
Cleveland, W. S.: Robust locally weighted regression and smoothing
scatterplots, J. Am. Stat. Assoc., 74, 829–836, https://doi.org/10.1080/01621459.1979.10481038, 1979. a
Cleveland, W. S. and Devlin, S. J.: Locally weighted regression: An approach
to regression analysis by local fitting, J. Am. Stat. Assoc., 83, 596–610, https://doi.org/10.1080/01621459.1988.10478639, 1988. a
Cook, S. J., Christoffersen, P., Todd, J., Slater, D., and Chauché, N.: Coupled modelling of subglacial hydrology and calving-front melting at Store Glacier, West Greenland, The Cryosphere, 14, 905–924, https://doi.org/10.5194/tc-14-905-2020, 2020. a, b, c
Cook, S. J., Christoffersen, P., and Todd, J.: A fully-coupled 3D model of a
large Greenlandic outlet glacier with evolving subglacial hydrology, frontal
plume melting and calving, J. Glaciol., https://doi.org/10.1017/jog.2021.109, in press, 2021. a
Cowton, T., Sole, A., Nienow, P., Slater, D., Wilton, D., and Hanna, E.:
Controls on the transport of oceanic heat to Kangerdlugssuaq Glacier, East
Greenland, J. Glaciol., 62, 1167–1180, https://doi.org/10.1017/jog.2016.117, 2016. a
Csatho, B. M., Schenka, A. F., Van Der Veen, C. J., Babonis, G., Duncan, K.,
Rezvanbehbahani, S., Van Den Broeke, M. R., Simonsen, S. B., Nagarajan, S.,
and Van Angelen, J. H.: Laser altimetry reveals complex pattern of Greenland Ice Sheet dynamics, P. Natl. Acad. Sci. USA, 111, 18478–18483,
https://doi.org/10.1073/pnas.1411680112, 2014. a
Cuffey, K. and Paterson, W.: The physics of glaciers, Academic Press, Amsterdam, 2010. a
Dapogny, C., Dobrzynski, C., and Frey, P.: Three-dimensional adaptive domain
remeshing, implicit domain meshing, and applications to free and moving
boundary problems, J. Comput. Phys., 262, 358–378, https://doi.org/10.1016/j.jcp.2014.01.005, 2014. a
Davison, B. J., Sole, A. J., Livingstone, S. J., Cowton, T. R., and Nienow, P. W.: The Influence of Hydrology on the Dynamics of Land-Terminating
Sectors of the Greenland Ice Sheet, Front. Earth Sci., 7, 1–24,
https://doi.org/10.3389/feart.2019.00010, 2019. a, b, c, d
de Fleurian, B., Morlighem, M., Seroussi, H., Rignot, E., van den Broeke,
M. R., Kuipers Munneke, P., Mouginot, J., Smeets, P. C. J. P., and Tedstone, A. J.: A modeling study of the effect of runoff variability on the effective pressure beneath Russell Glacier, West Greenland, J. Geophys. Res.-Earth, 121, 1834–1848, https://doi.org/10.1002/2016JF003842, 2016. a, b, c, d, e
De Fleurian, B., Werder, M. A., Beyer, S., Brinkerhoff, D. J., Delaney, I.,
Dow, C. F., Downs, J., Gagliardini, O., Hoffman, M. J., Hooke, R. L.,
Seguinot, J., and Sommers, A. N.: SHMIP the subglacial hydrology model
intercomparison Project, J. Glaciology, 64, 897–916, https://doi.org/10.1017/jog.2018.78, 2018. a
Derkacheva, A., Mouginot, J., Millan, R., Maier, N., and Gillet-Chaulet, F.:
Data Reduction Using Statistical and Regression Approaches for Ice Velocity
Derived by Landsat-8, Sentinel-1 and Sentinel-2, Remote Sens., 12, 1935,
https://doi.org/10.3390/rs12121935, 2020. a, b, c
Derkacheva, A., Mouginot, J., and Millan, R.: Satellite-observed surface flow speed within Russell sector, West Greenland, bi-weekly average of 2015–2019 (1.0), Zenodo [data set], https://doi.org/10.5281/zenodo.5535532, 2021a. a
Derkacheva, A., Gillet-Chaulet, F., and Mouginot, J.: Seasonal evolution of basal conditions within Russell sector, West Greenland, inverted from satellite observations of surface flow (1.0), Zenodo [data set], https://doi.org/10.5281/zenodo.5535624, 2021b. a
Doyle, S. H., Hubbard, A., Van De Wal, R. S., Box, J. E., Van As, D., Scharrer, K., Meierbachtol, T. W., Smeets, P. C., Harper, J. T., Johansson, E., Mottram, R. H., Mikkelsen, A. B., Wilhelms, F., Patton, H., Christoffersen, P., and Hubbard, B.: Amplified melt and flow of the Greenland ice sheet driven by late-summer cyclonic rainfall, Nat. Geosci., 8, 647–653, https://doi.org/10.1038/ngeo2482, 2015. a
Edwards, T. L., Fettweis, X., Gagliardini, O., Gillet-Chaulet, F., Goelzer, H., Gregory, J. M., Hoffman, M., Huybrechts, P., Payne, A. J., Perego, M., Price, S., Quiquet, A., and Ritz, C.: Effect of uncertainty in surface mass
balance-elevation feedback on projections of the future sea level
contribution of the Greenland ice sheet, The Cryosphere, 8, 195–208,
https://doi.org/10.5194/tc-8-195-2014, 2014. a
Elmer/Ice: Open Source Finite Element Software for Ice Sheet, Glaciers and Ice Flow Modelling, Elmer/Ice [code], http://elmerice.elmerfem.org/, last access: 21 February 2020. a
Fahnestock, M., Scambos, T., Moon, T., Gardner, A., Haran, T., and Klinger, M.: Rapid large-area mapping of ice flow using Landsat 8, Remote Sens. Environ., 185, 84–94, https://doi.org/10.1016/j.rse.2015.11.023, 2016. a
Fettweis, X., Hofer, S., Krebs-Kanzow, U., Amory, C., Aoki, T., Berends, C. J., Born, A., Box, J. E., Delhasse, A., Fujita, K., Gierz, P., Goelzer, H., Hanna, E., Hashimoto, A., Huybrechts, P., Kapsch, M.-L., King, M. D., Kittel, C., Lang, C., Langen, P. L., Lenaerts, J. T. M., Liston, G. E., Lohmann, G., Mernild, S. H., Mikolajewicz, U., Modali, K., Mottram, R. H., Niwano, M., Noël, B., Ryan, J. C., Smith, A., Streffing, J., Tedesco, M., van de Berg, W. J., van den Broeke, M., van de Wal, R. S. W., van Kampenhout, L., Wilton, D., Wouters, B., Ziemen, F., and Zolles, T.: GrSMBMIP: intercomparison of the modelled 1980–2012 surface mass balance over the Greenland Ice Sheet, The Cryosphere, 14, 3935–3958, https://doi.org/10.5194/tc-14-3935-2020, 2020. a
Fitzpatrick, A. A., Hubbard, A., Joughin, I., Quincey, D. J., As, D. V.,
Mikkelsen, A. P., Doyle, S. H., Hasholt, B., and Jones, G. A.: Ice flow
dynamics and surface meltwater flux at a land-terminating sector of the
Greenland ice sheet, J. Glaciol., 59, 687–696, https://doi.org/10.3189/2013JoG12J143, 2013. a, b
Flowers, G. E.: Modelling water flow under glaciers and ice sheets, P. Roy. Soc. A, 471, 20140907, https://doi.org/10.1098/rspa.2014.0907, 2015. a
Fountain, A. G. and Walder, J. S.: Water flow through temperate glaciers, Rev. Geophys., 36, 299–328, https://doi.org/10.1029/97RG03579, 1998. a
Fowler, A. C.: On the rheology of till, Ann. Glaciol., 37, 55–59,
https://doi.org/10.3189/172756403781815951, 2003. a
Gagliardini, O. and Meyssonnier, J.: Lateral boundary conditions for a local
anisotropic ice-flow model, Ann. Glaciol., 35, 503–509, https://doi.org/10.3189/172756402781817202, 2002. a
Gagliardini, O. and Werder, M. A.: Influence of increasing surface melt over
decadal timescales on land-terminating Greenland-type outlet glaciers, J. Glaciol., 64, 700–710, https://doi.org/10.1017/jog.2018.59, 2018. a, b, c, d
Gagliardini, O., Cohen, D., Råback, P., and Zwinger, T.: Finite-element
modeling of subglacial cavities and related friction law, J. Geophys. Res., 112, F02027, https://doi.org/10.1029/2006JF000576, 2007. a, b, c, d
Gagliardini, O., Zwinger, T., Gillet-Chaulet, F., Durand, G., Favier, L.,
de Fleurian, B., Greve, R., Malinen, M., Martín, C., Råback, P.,
Ruokolainen, J., Sacchettini, M., Schäfer, M., Seddik, H., and Thies, J.: Capabilities and performance of Elmer/Ice, a new-generation ice sheet model, Geosci. Model Dev., 6, 1299–1318, https://doi.org/10.5194/gmd-6-1299-2013, 2013. a, b, c
Gilbert, J. C. and Lemaréchal, C.: Some numerical experiments with
variable-storage quasi-Newton algorithms, Math. Program., 45, 407–435, https://doi.org/10.1007/BF01589113, 1989. a
Gillet-Chaulet, F., Gagliardini, O., Seddik, H., Nodet, M., Durand, G., Ritz,
C., Zwinger, T., Greve, R., and Vaughan, D. G.: Greenland ice sheet
contribution to sea-level rise from a new-generation ice-sheet model, The Cryosphere, 6, 1561–1576, https://doi.org/10.5194/tc-6-1561-2012, 2012. a
Gillet-Chaulet, F., Durand, G., Gagliardini, O., Mosbeux, C., Mouginot, J.,
Rémy, F., and Ritz, C.: Assimilation of surface velocities acquired
between 1996 and 2010 to constrain the form of the basal friction law under
Pine Island Glacier, Geophys. Res. Lett., 43, 10311–10321,
https://doi.org/10.1002/2016GL069937, 2016. a
Goelzer, H., Robinson, A., Seroussi, H., and van de Wal, R. S.: Recent
Progress in Greenland Ice Sheet Modelling, Curr. Clim. Change Rep., 3, 291–302, https://doi.org/10.1007/s40641-017-0073-y, 2017. a
Goelzer, H., Nowicki, S., Payne, A., Larour, E., Seroussi, H., Lipscomb, W. H., Gregory, J., Abe-Ouchi, A., Shepherd, A., Simon, E., Agosta, C., Alexander, P., Aschwanden, A., Barthel, A., Calov, R., Chambers, C., Choi, Y., Cuzzone, J., Dumas, C., Edwards, T., Felikson, D., Fettweis, X., Golledge, N. R., Greve, R., Humbert, A., Huybrechts, P., Le Clec'h, S., Lee, V., Leguy, G., Little, C., Lowry, D., Morlighem, M., Nias, I., Quiquet, A., Rückamp, M., Schlegel, N. J., Slater, D. A., Smith, R., Straneo, F., Tarasov, L., Van De Wal, R., and Van Den Broeke, M.: The future sea-level contribution of the Greenland ice sheet: A multi-model ensemble study of ISMIP6, The Cryosphere, 14, 3071–3096, https://doi.org/10.5194/tc-14-3071-2020, 2020. a, b
Greskowiak, J.: Tide-induced salt-fingering flow during submarine groundwater
discharge, Geophys. Res. Lett., 41, 6413–6419, https://doi.org/10.1002/2014GL061184, 2014. a, b, c
Habermann, M., Maxwell, D., and Truffer, M.: Reconstruction of basal properties in ice sheets using iterative inverse methods, J. Glaciol., 58, 795–807, https://doi.org/10.3189/2012JoG11J168, 2012. a
Habermann, M., Truffer, M., and Maxwell, D.: Error sources in basal yield
stress inversions for Jakobshavn Isbræ, Greenland, derived from residual
patterns of misfit to observations, J. Glaciol., 63, 999–1011,
https://doi.org/10.1017/jog.2017.61, 2017. a
Hansen, P. C.: The L-Curve and its Use in the Numerical Treatment of Inverse Problems, in: Computational Inverse Problems in Electrocardiology, edited by: Johnston, P., WIT Press, 119–142, 2001. a
Harper, J., Meierbachtol, T., Humphrey, N., Saito, J., and Stansberry, A.: Variability of Basal Meltwater Generation During Winter, Western Greenland Ice Sheet, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2021-179, in review, 2021. a
Harper, J. T., Humphrey, N. F., Meierbachtol, T. W., Graly, J. A., and Fischer, U. H.: Borehole measurements indicate hard bed conditions, Kangerlussuaq sector, western Greenland Ice Sheet, J. Geophys. Res.-Earth,
122, 1605–1618, https://doi.org/10.1002/2017JF004201, 2017. a, b, c, d
Harrington, J. A., Humphrey, N. F., and Harper, J. T.: Temperature distribution and thermal anomalies along a flowline of the Greenland ice
sheet, Ann. Glaciol., 56, 98–104, https://doi.org/10.3189/2015AoG70A945, 2015. a, b, c, d
Helanow, C., Iverson, N. R., Woodard, J. B., and Zoet, L. K.: A slip law for
hard-bedded glaciers derived from observed bed topography, Sci. Adv., 7, eabe7798, https://doi.org/10.1126/sciadv.abe7798, 2021. a
Helm, V., Humbert, A., and Miller, H.: Elevation and elevation change of
Greenland and Antarctica derived from CryoSat-2, The Cryosphere, 8, 1539–1559, https://doi.org/10.5194/tc-8-1539-2014, 2014. a
Hills, B. H., Harper, J. T., Humphrey, N. F., and Meierbachtol, T. W.:
Measured Horizontal Temperature Gradients Constrain Heat Transfer Mechanisms
in Greenland Ice, Geophys. Res. Lett., 44, 9778–9785, https://doi.org/10.1002/2017GL074917, 2017. a, b, c, d
Hoffman, M. J., Andrews, L. C., Price, S. A., Catania, G. A., Neumann, T. A.,
Lüthi, M. P., Gulley, J., Ryser, C., Hawley, R. L., and Morriss, B.:
Greenland subglacial drainage evolution regulated by weakly connected regions of the bed, Nat. Commun., 7, 13903, https://doi.org/10.1038/ncomms13903, 2016. a, b, c
Howat, I., Negrete, A., and Smith, B.: MEaSUREs Greenland Ice Mapping Project (GIMP) Digital Elevation Model (2.1), NASA National Snow and Ice Data Center Distributed Active Archive Center, Boulder, Colorado, USA, [data set], https://doi.org/10.5067/NV34YUIXLP9W, 2015. a
Howat, I. M., Negrete, A., and Smith, B. E.: The Greenland Ice Mapping Project (GIMP) land classification and surface elevation data sets, The Cryosphere, 8, 1509–1518, https://doi.org/10.5194/tc-8-1509-2014, 2014. a, b
Iken, A.: The effect of the subglacial water pressure on the sliding velocity
of a glacier in an idealized numerical model, J. Glaciol., 27, 407–421, https://doi.org/10.1017/S0022143000011448, 1981. a, b, c
Iverson, N. R.: Shear resistance and continuity of subglacial till: Hydrology
rules, J. Glaciol., 56, 1104–1114, https://doi.org/10.3189/002214311796406220, 2011. a
Iverson, N. R., Hooyer, T. S., and Baker, R. W.: Ring-shear studies of till
deformation: Coulomb-plastic behavior and distributed strain in glacier
beds, J. Glaciol., 44, 634–642, https://doi.org/10.1017/S0022143000002136, 1998. a, b
Jay-Allemand, M., Gillet-Chaulet, F., Gagliardini, O., and Nodet, M.:
Investigating changes in basal conditions of Variegated Glacier prior to and
during its 1982–1983 surge, The Cryosphere, 5, 659–672,
https://doi.org/10.5194/tc-5-659-2011, 2011. a, b, c
Joughin, I., MacAyeal, D. R., and Tulaczyk, S.: Basal shear stress of the Ross ice streams from control method inversions, J. Geophys. Res.-Solid, 109, 1–20, https://doi.org/10.1029/2003JB002960, 2004. a
Joughin, I., Das, S. B., King, M. A., Smith, B. E., and Howat, I. M.: Seasonal Speedup Along the Western Flank of the Greenland Ice Sheet, Science, 320, 781–783, 2008. a
Joughin, I., Smith, B. E., and Howat, I.: Greenland Ice Mapping Project: ice
flow velocity variation at sub-monthly to decadal timescales, The Cryosphere, 12, 2211–2227, https://doi.org/10.5194/tc-12-2211-2018, 2018. a
Joughin, I., Smith, B. E., and Schoof, C. G.: Regularized Coulomb Friction
Laws for Ice Sheet Sliding: Application to Pine Island Glacier, Antarctica,
Geophys. Res. Lett., 46, 4764–4771, https://doi.org/10.1029/2019GL082526, 2019. a, b
Kulessa, B., Hubbard, A. L., Booth, A. D., Bougamont, M., Dow, C. F., Doyle,
S. H., Christoffersen, P., Lindbäck, K., Pettersson, R., Fitzpatrick, A. A. W., and Jones, G. A.: Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow, Sci. Adv., 3, e1603071, https://doi.org/10.1126/sciadv.1603071, 2017. a, b, c
Larour, E., Utke, J., Csatho, B., Schenk, A., Seroussi, H., Morlighem, M.,
Rignot, E., Schlegel, N., and Khazendar, A.: Inferred basal friction and
surface mass balance of the Northeast Greenland Ice Stream using data
assimilation of ICESat (Ice Cloud and land Elevation Satellite) surface
altimetry and ISSM (Ice Sheet System Model), The Cryosphere, 8, 2335–2351,
https://doi.org/10.5194/tc-8-2335-2014, 2014. a
Le Clec'h, S., Charbit, S., Quiquet, A., Fettweis, X., Dumas, C., Kageyama,
M., Wyard, C., and Ritz, C.: Assessment of the Greenland ice sheet-atmosphere feedbacks for the next century with a regional atmospheric
model coupled to an ice sheet model, The Cryosphere, 13, 373–395,
https://doi.org/10.5194/tc-13-373-2019, 2019. a
Lemos, A., Shepherd, A., McMillan, M., and Hogg, A.: Seasonal Variations in
the Flow of Land-Terminating Glaciers in Central-West Greenland Using
Sentinel-1 Imagery, Remote Sens., 10, 1878, https://doi.org/10.3390/rs10121878, 2018. a, b
Lindbäck, K., Pettersson, R., Doyle, S. H., Helanow, C., Jansson, P.,
Kristensen, S. S., Stenseng, L., Forsberg, R., and Hubbard, A. L.: High-resolution ice thickness and bed topography of a land-terminating
section of the Greenland Ice Sheet, Earth Syst. Sci. Data, 6, 331–338,
https://doi.org/10.5194/essd-6-331-2014, 2014. a
MacAyeal, D. R.: A tutorial on the use of control methods in ice-sheet modeling, J. Glaciol., 39, 91–98, https://doi.org/10.1017/S0022143000015744, 1993. a
Maier, N., Humphrey, N., Meierbachtol, T., and Harper, J.: Deformation motion
tracks sliding changes through summer, western Greenland, J. Glaciol., https://doi.org/10.1017/jog.2021.87, in press, 2021b. a
Mangeney, A., Califano, F., and Castelnau, O.: Isothermal flow of an anisotropic ice sheet in the vicinity of an ice divide, J. Geophys. Res.-Solid, 101, 28189–28204, https://doi.org/10.1029/96jb01924, 1996. a
Meierbachtol, T., Harper, J., and Humphrey, N.: Basal drainage system response to increasing surface melt on the Greenland ice sheet, Science, 341,
777–779, https://doi.org/10.1126/science.1235905, 2013. a, b, c, d
Mikkelsen, A. B., Hubbard, A., Macferrin, M., Box, J. E., Doyle, S. H.,
Fitzpatrick, A., Hasholt, B., Bailey, H. L., Lindbäck, K., and Pettersson, R.: Extraordinary runoff from the Greenland ice sheet in 2012 amplified by hypsometry and depleted firn retention, The Cryosphere, 10,
1147–1159, https://doi.org/10.5194/tc-10-1147-2016, 2016. a
Millan, R., Mouginot, J., Rabatel, A., Jeong, S., Cusicanqui, D., Derkacheva,
A., and Chekki, M.: Mapping surface flow velocity of glaciers at regional
scale using a multiple sensors approach, Remote Sens., 11, 1–21,
https://doi.org/10.3390/rs11212498, 2019. a
Minchew, B., Simons, M., Björnsson, H., Pálsson, F., Morlighem, M.,
Seroussi, H., Larour, E., and Hensley, S.: Plastic bed beneath Hofsjökull ice cap, central Iceland, and the sensitivity of ice flow to surface meltwater flux, J. Glaciol., 62, 147–158, https://doi.org/10.1017/jog.2016.26, 2016. a
Morlighem, M., Rignot, E., Seroussi, H., Larour, E., Ben Dhia, H., and Aubry,
D.: A mass conservation approach for mapping glacier ice thickness, Geophys. Res. Lett., 38, 1–6, https://doi.org/10.1029/2011GL048659, 2011. a
Morlighem, M., Rignot, E., Mouginot, J., Wu, X., Seroussi, H., Larour, E., and Paden, J.: High-resolution bed topography mapping of Russell Glacier,
Greenland, inferred from Operation IceBridge data, J. Glaciol., 59, 1015–1023, https://doi.org/10.3189/2013JoG12J235, 2013. a
Morlighem, M., Williams, C. N., Rignot, E., An, L., Arndt, J. E., Bamber, J. L., Catania, G., Chauché, N., Dowdeswell, J. A., Dorschel, B., Fenty, I., Hogan, K., Howat, I., Hubbard, A., Jakobsson, M., Jordan, T. M., Kjeldsen, K. K., Millan, R., Mayer, L., Mouginot, J., Noël, B. P., O'Cofaigh, C., Palmer, S., Rysgaard, S., Seroussi, H., Siegert, M. J., Slabon, P., Straneo, F., van den Broeke, M. R., Weinrebe, W., Wood, M., and Zinglersen, K. B.: BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation, Geophys. Res. Lett., 44, 11051–11061, https://doi.org/10.1002/2017GL074954, 2017. a, b, c, d, e
Mouginot, J., Rignot, E., Scheuchl, B., and Millan, R.: Comprehensive Annual
Ice Sheet Velocity Mapping Using Landsat-8, Sentinel-1, and RADARSAT-2 Data,
Remote Sen., 9, 1–20, https://doi.org/10.3390/rs9040364, 2017. a, b, c
Mouginot, J., Rignot, E., Bjørk, A. A., van den Broeke, M., Millan, R.,
Morlighem, M., Noël, B., Scheuchl, B., and Wood, M.: Forty-six years
of Greenland Ice Sheet mass balance from 1972 to 2018, P. Natl. Acad. Sci. USA, 116, 9239–9244, https://doi.org/10.1073/pnas.1904242116, 2019. a
Nienow, P. W., Sole, A. J., Slater, D. A., and Cowton, T. R.: Recent Advances in Our Understanding of the Role of Meltwater in the Greenland Ice Sheet
System, Curr. Clim. Change Rep., 3, 330–344, https://doi.org/10.1007/s40641-017-0083-9, 2017. a, b, c
Palmer, S., Shepherd, A., Nienow, P., and Joughin, I.: Seasonal speedup of the Greenland Ice Sheet linked to routing of surface water, Earth Planet. Sc. Lett., 302, 423–428, https://doi.org/10.1016/j.epsl.2010.12.037, 2011. a, b, c
Pimentel, S., Flowers, G. E., and Schoof, C. G.: A hydrologically coupled
higher-order flow-band model of ice dynamics with a Coulomb friction sliding
law, J. Geophys. Res.-Earth, 115, 1–16, https://doi.org/10.1029/2009JF001621, 2010. a
Poinar, K., Joughin, I., Das, S. B., Behn, M. D., Lenaerts, J. T., and Van Den Broeke, M. R.: Limits to future expansion of surface-melt-enhanced ice flow into the interior of western Greenland, Geophys. Res. Lett., 42,
1800–1807, https://doi.org/10.1002/2015GL063192, 2015. a
Price, S. F., Payne, A. J., Catania, G. A., and Neumann, T. A.: Seasonal
acceleration of inland ice via longitudinal coupling to marginal ice, J. Glaciol., 54, 213–219, https://doi.org/10.3189/002214308784886117, 2008. a
Rignot, E. and Mouginot, J.: Ice flow in Greenland for the International Polar Year 2008–2009, Geophys. Res. Lett., 39, 1–7, https://doi.org/10.1029/2012GL051634, 2012. a
Ryser, C., Lüthi, M. P., Andrews, L. C., Catania, G. A., Funk, M., and
Hawley, R.: Caterpillar-like ice motion in the ablation zone of the Greenland ice sheet, J. Geophys. Res.-Earth, 119, 2258–2271, https://doi.org/10.1002/2013JF003067, 2014a. a
Ryser, C., Luthi, M. P., Andrews, L. C., Hoffman, M. J., Catania, G. A.,
Hawley, R. L., Neumann, T. A., and Kristensen, S. S.: Sustained high basal
motion of the Greenland ice sheet revealed by borehole deformation, J. Glaciol., 60, 647–660, https://doi.org/10.3189/2014JoG13J196, 2014b. a, b
Scambos, T. A. and Haran, T.: An image-enhanced DEM of the Greenland ice
sheet, Ann. Glaciol., 34, 291–298, https://doi.org/10.3189/172756402781817969, 2002. a
Schäfer, M., Gillet-Chaulet, F., Gladstone, R., Pettersson, R., Pohjola,
V. A., Strozzi, T., and Zwinger, T.: Assessment of heat sources on the control of fast flow of Vestfonna ice cap, Svalbard, The Cryosphere, 8,
1951–1973, https://doi.org/10.5194/tc-8-1951-2014, 2014. a
Schoof, C.: The effect of cavitation on glacier sliding, P. Roy. Soc. A, 461,
609–627, https://doi.org/10.1098/rspa.2004.1350, 2005. a, b, c, d
Shapero, D. R., Joughin, I. R., Poinar, K., Morlighem, M., and Gillet-Chaulet, F.: Basal resistance for three of the largest Greenland outlet glaciers, J. Geophys. Res.-Earth, 121, 168–180,
https://doi.org/10.1002/2015JF003643, 2016. a
Smeets, C. J. P. P., Boot, W., Hubbard, A., Pettersson, R., Wilhelms, F., Van Den Broeke, M. R., and Van De Wal, R. S. W.: A wireless subglacial probe for deep ice applications, Instrum. Meth., 58, 841–848,
https://doi.org/10.3189/2012JoG11J130, 2012. a, b, c
Smith, L. C., Chu, V. W., Yang, K., Gleason, C. J., Pitcher, L. H., Rennermalm, A. K., Legleiter, C. J., Behar, A. E., Overstreet, B. T., Moustafa, S. E., Tedesco, M., Forster, R. R., LeWinter, A. L., Finnegan, D. C., Sheng, Y., and Balog, J.: Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet, P. Natl. Acad. Sci. USA, 112, 1001–1006, https://doi.org/10.1073/pnas.1413024112, 2015. a
Sole, A., Nienow, P., Bartholomew, I., Mair, D., Cowton, T., Tedstone, A., and King, M. A.: Winter motion mediates dynamic response of the Greenland Ice
Sheet to warmer summers, Geophys. Res. Lett., 40, 3940–3944,
https://doi.org/10.1002/grl.50764, 2013. a, b
Stevens, L. A., Behn, M. D., Das, S. B., Joughin, I., Noël, B. P., van den Broeke, M. R., and Herring, T.: Greenland Ice Sheet flow response to
runoff variability, Geophys. Res. Lett., 43, 11295–11303,
https://doi.org/10.1002/2016GL070414, 2016. a, b
Sugiyama, S. and Gudmundsson, G. H.: Short-term variations in glacier flow
controlled by subglacial water pressure at Lauteraargletscher, Bernese Alps,
Switzerland, J. Glaciol., 50, 353–362, https://doi.org/10.3189/172756504781829846, 2004. a
Sundal, A. V., Shepherd, A., Nienow, P., Hanna, E., Palmer, S., and Huybrechts, P.: Melt-induced speed-up of Greenland ice sheet offset by efficient subglacial drainage, Nature, 469, 521–524, https://doi.org/10.1038/nature09740, 2011. a
Tedstone, A., Nienow, P. W., Gourmelen, N., Dehecq, A., Goldberg, D., and
Hanna, E.: Decadal slowdown of a land-terminating sector of the Greenland
Ice Sheet despite warming, Nature, 526, 692–695, https://doi.org/10.1038/nature15722,
2015. a, b
Tedstone, A. J., Nienow, P. W., Sole, A. J., Mair, D. W. F., Cowton, T. R.,
Bartholomew, I. D., and King, M. A.: Greenland ice sheet motion insensitive
to exceptional meltwater forcing, P. Natl. Acad. Sci. USA, 110, 19719–19724, https://doi.org/10.1073/pnas.1315843110, 2013. a
Tedstone, A. J., Nienow, P. W., Gourmelen, N., and Sole, A. J.: Greenland ice
sheet annual motion insensitive to spatial variations in subglacial hydraulic
structure, Geophys. Res. Lett., 41, 8910–8917, https://doi.org/10.1002/2014GL062386, 2014. a
Truffer, M., Harrison, W. D., and Echelmeyer, K. A.: Glacier motion dominated
by processes deep in underlying till, J. Glaciol., 46, 213–221,
https://doi.org/10.3189/172756500781832909, 2000. a
Trusel, L. D., Das, S. B., Osman, M. B., Evans, M. J., Smith, B. E., Fettweis, X., McConnell, J. R., Noël, B. P., and van den Broeke, M. R.:
Nonlinear rise in Greenland runoff in response to post-industrial Arctic
warming, Nature, 564, 104–108, https://doi.org/10.1038/s41586-018-0752-4, 2018. a
Van De Wal, R. S., Boot, W., Smeets, C. J., Snellen, H., Van Den Broeke, M. R., and Oerlemans, J.: Twenty-one years of mass balance observations along the K-transect, West Greenland, Earth Syst. Sci. Data, 4, 31–35,
https://doi.org/10.5194/essd-4-31-2012, 2012. a
Van De Wal, R. S., Smeets, C. J., Boot, W., Stoffelen, M., Van Kampen, R.,
Doyle, S. H., Wilhelms, F., Van Den Broeke, M. R., Reijmer, C. H., Oerlemans, J., and Hubbard, A.: Self-regulation of ice flow varies across the ablation area in south-west Greenland, The Cryosphere, 9, 603–611,
https://doi.org/10.5194/tc-9-603-2015, 2015. a, b, c, d, e, f
Van Tricht, K., Lhermitte, S., Lenaerts, J. T., Gorodetskaya, I. V., L'Ecuyer, T. S., Noël, B., Van Den Broeke, M. R., Turner, D. D., and
Van Lipzig, N. P.: Clouds enhance Greenland ice sheet meltwater runoff, Nat. Commun., 7, 10266, https://doi.org/10.1038/ncomms10266, 2016. a
Vijay, S., Khan, S. A., Kusk, A., Solgaard, A. M., Moon, T., and Bjørk,
A. A.: Resolving Seasonal Ice Velocity of 45 Greenlandic Glaciers With Very
High Temporal Details, Geophys. Res. Lett., 46, 1485–1495,
https://doi.org/10.1029/2018GL081503, 2019. a
Weertman, J.: On the sliding of glaciers, J. Glaciol., 3, 33–38, https://doi.org/10.1007/978-94-015-8705-1_19, 1957. a
Yang, Y., Li, F., Hwang, C., Ding, M., and Ran, J.: Space-Time Evolution of
Greenland Ice Sheet Elevation and Mass From Envisat and GRACE Data, J. Geophys. Res.-Earth, 124, 2079–2100, https://doi.org/10.1029/2018JF004765, 2019. a
Young, T. J., Christoffersen, P., Doyle, S. H., Nicholls, K. W., Stewart, C. L., Hubbard, B., Hubbard, A., Lok, L. B., Brennan, P. V., Benn, D. I., Luckman, A., and Bougamont, M.: Physical Conditions of Fast Glacier Flow:
3. Seasonally-Evolving Ice Deformation on Store Glacier, West Greenland, J. Geophys. Res.-Earth, 124, 245–267, https://doi.org/10.1029/2018JF004821, 2019.
a
Zoet, L. K. and Iverson, N. R.: A slip law for glaciers on deformable beds,
Science, 368, 76–78, https://doi.org/10.1126/science.aaz1183, 2020. a
Zwally, H. J., Abdalati, W., Herring, T., Larson, K., Saba, J., and Steffen,
K.: Surface melt-induced acceleration of Greenland ice-sheet flow, Science,
297, 218–222, https://doi.org/10.1126/science.1072708, 2002. a
Short summary
Along the edges of the Greenland Ice Sheet surface melt lubricates the bed and causes large seasonal fluctuations in ice speeds during summer. Accurately understanding how these ice speed changes occur is difficult due to the inaccessibility of the glacier bed. We show that by using surface velocity maps with high temporal resolution and numerical modelling we can infer the basal conditions that control seasonal fluctuations in ice speed and gain insight into seasonal dynamics over large areas.
Along the edges of the Greenland Ice Sheet surface melt lubricates the bed and causes large...
