Bed topography; Dynamic component; Greenland; Greenland Ice Sheet; Ice sheet; Mass loss; Sea level rise; Geophysics; Earth and Planetary Sciences (all); General Earth and Planetary Sciences
Abstract :
[en] Greenland's outlet glaciers have been a leading source of mass loss and accompanying sea-level rise from the Greenland Ice Sheet (GrIS) over the last 25 years. The dynamic component of outlet glacier mass loss depends on both the ice flux through the terminus and the inland extent of glacier thinning, initiated at the ice-ocean interface. Here, we find limits to the inland spread of thinning that initiates at glacier termini for 141 ocean-terminating outlet glaciers around the GrIS. Inland diffusion of thinning is limited by steep reaches of bed topography that we call "knickpoints." We show that knickpoints exist beneath the majority of outlet glaciers but they are less steep in regions of gentle bed topography, giving glaciers in gentle bed topography the potential to contribute to ongoing and future mass loss from the GrIS by allowing the diffusion of thinning far into the ice sheet interior.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Felikson, Denis ; Cryospheric Sciences Laboratory NASA Goddard Space Flight Center Greenbelt MD USA ; Goddard Earth Sciences Technology and Research Studies and Investigations Universities Space Research Association Columbia MD USA
A Catania, Ginny ; University of Texas Institute for Geophysics University of Texas at Austin Austin TX USA ; Department of Geological Sciences University of Texas at Austin Austin TX USA
Bartholomaus, Timothy C ; Department of Geological Sciences University of Idaho Moscow ID USA
Morlighem, Mathieu ; Department of Earth System Science University of California, Irvine Irvine CA USA
Noël, Brice ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie ; Institute for Marine and Atmospheric Research Utrecht Utrecht University Utrecht The Netherlands
Language :
English
Title :
Steep Glacier Bed Knickpoints Mitigate Inland Thinning in Greenland.
NASA - National Aeronautics and Space Administration [US-DC] [US-DC] NWO - Nederlandse Organisatie voor Wetenschappelijk Onderzoek [NL]
Funding text :
We wish to thank two anonymous reviewers of this manuscript for their particular attention to detail and constructive comments. This research was funded by NASA grant NNX12AP50G, the Gale White Fellowship at the University of Texas Institute for Geophysics, and the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by Universities Space Research Association under contract with NASA. B. P. Y. Noël was funded by NWO VENI grant VI.Veni.192.019. ArcticDEM was provided by the Polar Geospatial Center under NSF OPP awards 1043681, 1559691, and 1542736.
Bevan, S. L., Luckman, A. J., & Murray, T. (2012). Glacier dynamics over the last quarter of a century at Helheim, Kangerdlugssuaq and 14 other major Greenland outlet glaciers. The Cryosphere, 6(5), 923–937. http://dx.doi.org/10.5194/tc-6-923-2012
Bindschadler, R. A. (1997). Actively surging West Antarctic ice streams and their response characteristics. Annals of Glaciology, 24, 409–414. http://dx.doi.org/10.3189/s0260305500012520
Carr, J. R., Stokes, C., & Vieli, A. (2014). Recent retreat of major outlet glaciers on Novaya Zemlya, Russian Arctic, influenced by fjord geometry and sea-ice conditions. Journal of Glaciology, (60)(219), 155–170. http://dx.doi.org/10.3189/2014jog13j122
Catania, G. A., Stearns, L. A., Sutherland, D. A., Fried, M. J., Bartholomaus, T. C., Morlighem, M., Shroyer, E., & Nash, J. (2018). Geometric Controls on Tidewater Glacier Retreat in Central Western Greenland. Journal of Geophysical Research: Earth Surface, 123(8), 2024–2038. http://dx.doi.org/10.1029/2017jf004499
Csatho, B. M., Schenk, A. F., van der Veen, C. J., Babonis, G., Duncan, K., Rezvanbehbahani, S., van den Broeke, M. R., Simonsen, S. B., Nagarajan, S., & van Angelen, J. H. (2014). Laser altimetry reveals complex pattern of Greenland Ice Sheet dynamics. Proceedings of the National Academy of Sciences, 111(52), 18478–18483. http://dx.doi.org/10.1073/pnas.1411680112
Felikson, D., Bartholomaus, T. C., Catania, G. A., Korsgaard, N. J., Kjær, K. H., Morlighem, M., Noël, B., van den Broeke, M., Stearns, L. A., Shroyer, E. L., Sutherland, D. A., & Nash, J. D. (2017). Inland thinning on the Greenland ice sheet controlled by outlet glacier geometry. Nature Geoscience, 10(5), 366–369. http://dx.doi.org/10.1038/ngeo2934
Gudmundsson, G. H., Krug, J., Durand, G., Favier, L., & Gagliardini, O. (2012). The stability of grounding lines on retrograde slopes. The Cryosphere, 6(6), 1497–1505. http://dx.doi.org/10.5194/tc-6-1497-2012
Bernard, H. (1979). A Theoretical Model of Glacial Abrasion. Journal of Glaciology, 23(89), 39–50. http://dx.doi.org/10.3189/s0022143000029725
Herman, F., Beyssac, O., Brughelli, M., Lane, S. N., Leprince, S., Adatte, T., Lin, J. Y. Y., Avouac, J.-P., & Cox, S. C. (2015). Erosion by an Alpine glacier. Science, 350(6257), 193–195. http://dx.doi.org/10.1126/science.aab2386
Holland, D. M., Thomas, R. H., de Young, B., Ribergaard, M. H., & Lyberth, B. (2008). Acceleration of Jakobshavn Isbræ triggered by warm subsurface ocean waters. Nature Geoscience, 1(10), 659–664. http://dx.doi.org/10.1038/ngeo316
Howat, I. M., Negrete, A., & Smith, B. E. (2014). The Greenland Ice Mapping Project (GIMP) land classification and surface elevation data sets. The Cryosphere, 8(4), 1509–1518. http://dx.doi.org/10.5194/tc-8-1509-2014
Jamieson, S. S. R., Vieli, A., Cofaigh, C. Ó, Stokes, C. R., Livingstone, S. J., & Hillenbrand, C.-D. (2014). Understanding controls on rapid ice-stream retreat during the last deglaciation of Marguerite Bay, Antarctica, using a numerical model. Journal of Geophysical Research: Earth Surface, 119(2), 247–263. http://dx.doi.org/10.1002/2013jf002934
Jamieson, S. S. R., Vieli, A., Livingstone, S. J., Cofaigh, C. Ó, Stokes, C., Hillenbrand, C.-D., & Dowdeswell, J. A. (2012). Ice-stream stability on a reverse bed slope. Nature Geoscience, 5(11), 799–802. http://dx.doi.org/10.1038/ngeo1600
Joughin, I., Moon, T., Joughin, J., & Black, T. (2017). MEaSUREs Annual Greenland Outlet Glacier Terminus Positions from SAR Mosaics, Version 1. Boulder, CO: NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/DC0MLBOCL3EL421 https://doi.org/10.5067/DC0MLBOCL3EL
Kamb, B., & Echelmeyer, K. A. (1986). Stress-Gradient Coupling in Glacier Flow: I. Longitudinal Averaging of the Influence of Ice Thickness and Surface Slope. Journal of Glaciology, 32(111), 267–284. http://dx.doi.org/10.3189/s0022143000015604
Kessler, M. A., Anderson, R. S., & Briner, J. P. (2008). Fjord insertion into continental margins driven by topographic steering of ice. Nature Geoscience, 1(6), 365–369. http://dx.doi.org/10.1038/ngeo201
Khan, S. A., Kjær, K. H., Bevis, M., Bamber, J. L., Wahr, J., Kjeldsen, K. K., Bjørk, A. A., Korsgaard, N. J., Stearns, L. A., van den Broeke, M. R., Liu, L., Larsen, N. K., & Muresan, I. S. (2014). Sustained mass loss of the northeast Greenland ice sheet triggered by regional warming. Nature Climate Change, 4(4), 292–299. http://dx.doi.org/10.1038/nclimate2161
King, M. D., Howat, I. M., Candela, S. G., Noh, M. J., Jeong, S., Noël, B. P. Y., van den Broeke, M. R., Wouters, B., & Negrete, A. (2020). Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat. Communications Earth & Environment, 1(1). http://dx.doi.org/10.1038/s43247-020-0001-2
Kjaer, K. H., Khan, S. A., Korsgaard, N. J., Wahr, J., Bamber, J. L., Hurkmans, R., van den Broeke, M., Timm, L. H., Kjeldsen, K. K., Bjork, A. A., Larsen, N. K., Jorgensen, L. T., Faerch-Jensen, A., & Willerslev, E. (2012). Aerial Photographs Reveal Late-20th-Century Dynamic Ice Loss in Northwestern Greenland. Science, 337(6094), 569–573. http://dx.doi.org/10.1126/science.1220614
Koppes, M. N., & Montgomery, D. R. (2009). The relative efficacy of fluvial and glacial erosion over modern to orogenic timescales. Nature Geoscience, 2(9), 644–647. http://dx.doi.org/10.1038/ngeo616
Korsgaard, N. J., Nuth, C., Khan, S. A., Kjeldsen, K. K., Bjørk, A. A., Schomacker, A., & Kjær, K. H. (2016). Digital elevation model and orthophotographs of Greenland based on aerial photographs from 1978–1987. Scientific Data, 3(1). http://dx.doi.org/10.1038/sdata.2016.32
Larsen, S. H., Khan, S. A., Ahlstrøm, A. P., Hvidberg, C. S., Willis, M. J., & Andersen, S. B. (2016). Increased mass loss and asynchronous behavior of marine-terminating outlet glaciers at Upernavik Isstrøm, NW Greenland. Journal of Geophysical Research: Earth Surface, 121(2), 241–256. http://dx.doi.org/10.1002/2015jf003507
McFadden, E. M., Howat, I. M., Joughin, I., Smith, B. E., & Ahn, Y. (2011). Changes in the dynamics of marine terminating outlet glaciers in west Greenland (2000-2009). Journal of Geophysical Research: Earth Surface, 116(F2). http://dx.doi.org/10.1029/2010jf001757
McKerrow, W. S., Mac Niocaill, C., & Dewey, J. F. (2000). The Caledonian Orogeny redefined. Journal of the Geological Society, 157(6), 1149–1154. http://dx.doi.org/10.1144/jgs.157.6.1149
Moon, T., & Joughin, I. (2008). Changes in ice front position on Greenland's outlet glaciers from 1992 to 2007. Journal of Geophysical Research, 113(F2). http://dx.doi.org/10.1029/2007jf000927
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. Y., 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., & Zinglersen, K. B. (2017). BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation. Geophysical Research Letters, 44(21), 11051–11061. http://dx.doi.org/10.1002/2017gl074954
Mouginot, J., Rignot, E., Bjørk, A. A., van den Broeke, M., Millan, R., Morlighem, M., Noël, B., Scheuchl, B., & Wood, M. (2019). Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018. Proceedings of the National Academy of Sciences, 116(19), 9239–9244. http://dx.doi.org/10.1073/pnas.1904242116
Nick, F. M., Vieli, A., Howat, I. M., & Joughin, I. (2009). Large-scale changes in Greenland outlet glacier dynamics triggered at the terminus. Nature Geoscience, 2(2), 110–114. http://dx.doi.org/10.1038/ngeo394
Noël, B., van de Berg, W. J., Lhermitte, S., & van den Broeke, M. R. (2019). Rapid ablation zone expansion amplifies north Greenland mass loss. Science Advances, 5(9), eaaw0123. http://dx.doi.org/10.1126/sciadv.aaw0123
Nye, J. F. (1960). The response of glaciers and ice-sheets to seasonal and climatic changes. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 256(1287), 559–584. http://dx.doi.org/10.1098/rspa.1960.0127
Payne, A. J., Vieli, A., Shepherd, A. P., Wingham, D. J., & Rignot, E. (2004). Recent dramatic thinning of largest West Antarctic ice stream triggered by oceans. Geophysical Research Letters, 31(23), L23401. http://dx.doi.org/10.1029/2004gl021284
Porter, C., Morin, P., Howat, I., Noh, M.-J., Bates, B., Peterman, K., et al. (2018). ArcticDEM. Harvard Dataverse, V1. https://doi.org/10.7910/DVN/OHHUKH
Price, S. F., Payne, A. J., Howat, I. M., & Smith, B. E. (2011). Committed sea-level rise for the next century from Greenland ice sheet dynamics during the past decade. Proceedings of the National Academy of Sciences, 108(22), 8978–8983. http://dx.doi.org/10.1073/pnas.1017313108
Rignot, E., & Mouginot, J. (2012). Ice flow in Greenland for the International Polar Year 2008-2009. Geophysical Research Letters, 39(11), n/a–n/a. http://dx.doi.org/10.1029/2012gl051634
Robel, A. A., Schoof, C., & Tziperman, E. (2016). Persistence and variability of ice-stream grounding lines on retrograde bed slopes. The Cryosphere, 10(4), 1883–1896. http://dx.doi.org/10.5194/tc-10-1883-2016
Roberts, G. G., & White, N. (2010). Estimating uplift rate histories from river profiles using African examples. Journal of Geophysical Research, 115(B2). http://dx.doi.org/10.1029/2009jb006692
Schoof, C. (2007). Ice sheet grounding line dynamics: Steady states, stability, and hysteresis. Journal of Geophysical Research, 112(F3). http://dx.doi.org/10.1029/2006jf000664
Steiger, N., Nisancioglu, K. H., Åkesson, H., de Fleurian, B., & Nick, F. M. (2018). Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry. The Cryosphere, 12(7), 2249–2266. http://dx.doi.org/10.5194/tc-12-2249-2018
van der Veen, C. J. (2001). Greenland ice sheet response to external forcing. Journal of Geophysical Research: Atmospheres, 106(D24), 34047–34058. http://dx.doi.org/10.1029/2001jd900032
Velicogna, I., Sutterley, T. C., & van den Broeke, M. R. (2014). Regional acceleration in ice mass loss from Greenland and Antarctica using GRACE time-variable gravity data. Geophysical Research Letters, 41(22), 8130–8137. http://dx.doi.org/10.1002/2014gl061052
Weertman, J. (1957). On the Sliding of Glaciers. Journal of Glaciology, 3(21), 33–38. http://dx.doi.org/10.3189/s0022143000024709
Willett, S. D., McCoy, S. W., Perron, J. T., Goren, L., & Chen, C.-Y. (2014). Dynamic Reorganization of River Basins. Science, 343(6175), 1248765. http://dx.doi.org/10.1126/science.1248765
Williams, C. R., Hindmarsh, R. C. A., & Arthern, R. J. (2012). Frequency response of ice streams. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 468(2147), 3285–3310. http://dx.doi.org/10.1098/rspa.2012.0180
Cuffey, K., & Paterson, W. S. B. (2010). The physics of glaciers (4th ed.). Academic Press.
Howat, I. M., & Eddy, A. (2011). Multi-decadal retreat of Greenland’s marine-terminating glaciers. Journal of Glaciology, 57(203), 389–396. https://doi.org/10.3189/002214311796905631
Hutter, K. (1983). Theoretical glaciology: Material science of ice and the mechanics of glaciers and ice sheets. Dordrecht, The Netherlands: Reidel Publishing.
Joughin, I., Smith, B., Howat, I., & Scambos, T. (2016). MEaSUREs Multi-year Greenland Ice Sheet Velocity Mosaic, Version 1. Boulder, CO: NASA National Snow and Ice Data Center Distributed Active Archive Center. https://dx.doi.org/10.5067/QUA5Q9SVMSJG
Joughin, I., Smith, B. E., & Howat, I. M. (2018). A complete map of Greenland ice velocity derived from satellite data collected over 20 years. Journal of Glaciology, 64(243), 1–11. https://doi.org/10.1017/jog.2017.73
Morlighem, M. (2017). IceBridge BedMachine Greenland, Version 3. Boulder, CO: NASA National Snow and Ice Data Center Distributed Active Archive Center. https://dx.doi.org/10.5067/2CIX82HUV88Y
Murray, T., Scharrer, K., Selmes, N., Booth, A. D., James, T. D., Bevan, S. L., et al. (2015). Extensive retreat of Greenland tidewater glaciers, 2000–2010. Arctic, Antarctic, and Alpine Research, 47(3), 427–447. http://dx.doi.org/10.1657/aaar0014-049
Noh, M. J., & Howat, I. M. (2015). Automated stereo-photogrammetric DEM generation at high latitudes: Surface Extraction with TIN-based Search-space Minimization (SETSM) validation and demonstration over glaciated regions. GIScience & Remote Sensing, 52(2), 198–217. https://doi.org/10.1080/15481603.2015.1008621
Rignot, E., Box, J. E., Burgess, E., & Hanna, E. (2008). Mass balance of the Greenland ice sheet from 1958 to 2007. Geophysical Research Letters, 35(20). https://doi.org/10.1029/2008gl035417
van As, D., Hasholt, B., Ahlstrøm, A. P., Box, J. E., Cappelen, J., Colgan, W. et al. (2018). Reconstructing Greenland Ice Sheet meltwater discharge through the Watson River (1949–2017). Arctic, Antarctic, and Alpine Research, 50(1), S100010. http://dx.doi.org/10.1080/15230430.2018.1433799
Wake, L.M., Lecavalier, B. S., & Bevis, M. (2016). Glacial Isostatic Adjustment (GIA) in Greenland: a Review. Current Climate Change Reports, 2, 101–111. https://doi.org/10.1007/s40641-016-0040-z
Zwally, H. J., Giovinetto, M. B., Beckley, M. A., & Saba, J. L. (2012). Antarctic and Greenland Drainage Systems, GSFC Cryospheric Sciences Laboratory. Retrieved from https://icesat4.gsfc.nasa.gov/cryo_data/ant_grn_drainage_systems.php
