Abstract
As the global climate warms, increased surface meltwater production on ice shelves may trigger ice-shelf collapse and enhance global sea-level rise. The formation of surface rivers could help prevent ice-shelf collapse if they can efficiently evacuate meltwater. Here we present observations of the evolution of a surface river into an ice-shelf estuary atop the Petermann Ice Shelf in northwest Greenland and identify a second estuary at the nearby Ryder Ice Shelf. This surface-hydrology process can foster fracturing and enhance calving. At the Petermann estuary, sea ice was observed converging at the river mouth upstream, indicating a flow reversal. Seawater persists in the estuary after the surrounding icescape is frozen. Along the base of Petermann estuary, linear fractures were initiated at the calving front and propagated upstream along the channel. Similar fractures along estuary channels shaped past large rectilinear calving events at the Petermann and Ryder ice shelves. Increased surface melting in a warming world will enhance fluvial incision, promoting estuary development and longitudinal fracturing orthogonal to ice-shelf fronts, and increase rectilinear calving. Estuaries could develop in Antarctica within the next half-century, resulting in increased calving and accelerating both ice loss and global sea-level rise.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
Except for DigitalGlobe constellation data, all datasets used in this analysis are freely available. DigitalGlobe satellite imagery was provided by the PGC under National Science Foundation grant 1644869 and is available from the PGC upon request with eligible active research awards. Imagery-derived river widths and fracture length developed in this analysis are available at http://wonder.ldeo.columbia.edu/data/publicationData/Boghosian/Estuary/, along with MAR data used. Landsat data are available at https://earthexplorer.usgs.gov and the Landsat Image Mosaic of Antarctica is available at https://nimbus.cr.usgs.gov/landing/. OIB data are provided by the National Snow and Ice Data Center at https://nsidc.org/. The 1978 orthophotos are provided by the National Oceanic and Atmospheric Administration National Centers for Environmental Information at https://www.nodc.noaa.gov/archive/arc0088/0145405/1.1/data/0-data/G150AERODEM/Orthorectified/. Ice-shelf elevation data are available at https://sealevel.nasa.gov/data/dataset/?identifier=SLCP_ice_shelf_dhdt_v1_1. REMA data are available through the PGC at https://www.pgc.umn.edu/data/rema/.
Code availability
This analysis does not depend on specific code. All results can be reproduced through the equations and procedures outlined in the Methods section of this manuscript.
References
Paolo, F. S., Fricker, H. A. & Padman, L. Volume loss from Antarctic ice shelves is accelerating. Science 348, 327–331 (2015).
Rignot, E., Jacobs, S., Mouginot, J. & Scheuchl, B. Ice-shelf melting around Antarctica. Science 341, 266–270 (2013).
Banwell, A. F., MacAyeal, D. R. & Sergienko, O. V. Breakup of the Larsen B Ice Shelf triggered by chain reaction drainage of supraglacial lakes. Geophys. Res. Lett. 40, 5872–5876 (2013).
Banwell, A. F. & MacAyeal, D. R. Ice-shelf fracture due to viscoelastic flexure stress induced by fill/drain cycles of supraglacial lakes. Antarct. Sci. 27, 587–597 (2015).
MacAyeal, D. R., Sergienko, O. V. & Banwell, A. F. A model of viscoelastic ice-shelf flexure. J. Glaciol. 61, 635–645 (2015).
Scambos, T. et al. Ice shelf disintegration by plate bending and hydro-fracture: satellite observations and model results of the 2008 Wilkins Ice Shelf break-ups. Earth Planet. Sci. Lett. 280, 51–60 (2009).
Kingslake, J., Ely, J. C., Das, I. & Bell, R. E. Widespread movement of meltwater onto and across Antarctic ice shelves. Nature 544, 349–352 (2017).
Bell, R. E. et al. Antarctic ice shelf potentially stabilized by export of meltwater in surface river. Nature 544, 344–348 (2017).
Dow, C. F. et al. Basal channels drive active surface hydrology and transverse ice shelf fracture. Sci. Adv. 4, eaao7212 (2018).
DeConto, R. M. & Pollard, D. Contribution of Antarctica to past and future sea-level rise. Nature 531, 591–597 (2016).
Smith, L. C. et al. Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet. Proc. Natl Acad. Sci. USA 112, 1001–1006 (2015).
Trusel, L. D. et al. Divergent trajectories of Antarctic surface melt under two twenty-first-century climate scenarios. Nat. Geosci. 8, 927–932 (2015).
Dutrieux, P. et al. Basal terraces on melting ice shelves. Geophys. Res. Lett. 41, 5506–5513 (2014).
Rignot, E. & Steffen, K. Channelized bottom melting and stability of floating ice shelves. Geophys. Res. Lett. 35, L02503 (2008).
Hill, E. A., Carr, J. R. & Stokes, C. R. A review of recent changes in major marine-terminating outlet glaciers in northern Greenland. Front. Earth Sci. 4, 111 (2017).
Macdonald, G. J., Banwell, A. F. & MacAyeal, D. R. Seasonal evolution of supraglacial lakes on a floating ice tongue, Petermann Glacier, Greenland. Ann. Glaciol. 59, 56–65 (2018).
Korsgaard, N. J. et al. Digital elevation model and orthophotographs of Greenland based on aerial photographs from 1978–1987. Sci. Data 3, 160032 (2016).
Münchow, A., Padman, L. & Fricker, H. A. Interannual changes of the floating ice shelf of Petermann Gletscher, north Greenland, from 2000 to 2012. J. Glaciol. 60, 489–499 (2014).
Holland, P. G. et al. in Encyclopedia of Hydrology and Water Resources (ed. Herschy, W. R.) 244–248 (Springer, 1998).
Johnson, H. L., Münchow, A., Falkner, K. K. & Melling, H. Ocean circulation and properties in Petermann Fjord, Greenland. J. Geophys. Res. Oceans 116, C01003 (2011).
Hill, E. A., Carr, J. R., Stokes, C. R. & Gudmundsson, G. H. Dynamic changes in outlet glaciers in northern Greenland from 1948 to 2015. Cryosphere 12, 3243–3263 (2018).
Pitcher, L. H. & Smith, L. C. Supraglacial streams and rivers. Annu. Rev. Earth Planet. Sci. 47, 421–452 (2019).
Scambos, T. A., Hulbe, C. & Fahnestock, M. in Antarctic Peninsula Climate Variability: Historical and Paleoenvironmental Perspectives (eds Domack, E. et al.) 79–92 (American Geophysical Union, 2003).
Lazzara, M. A., Jezek, K. C., Scambos, T. A., MacAyeal, D. R. & van der Veen, C. J. On the recent calving of icebergs from the Ross Ice Shelf. Polar Geogr. 23, 201–212 (1999).
Doake, C. S. M., Corr, H. F. J., Rott, H., Skvarca, P. & Young, N. W. Breakup and conditions for stability of the northern Larsen Ice Shelf, Antarctica. Nature 391, 778–780 (1998).
Bassis, J. N. & Ma, Y. Evolution of basal crevasses links ice shelf stability to ocean forcing. Earth Planet. Sci. Lett. 409, 203–211 (2015).
Hill, E. A., Gudmundsson, G. H., Carr, J. R. & Stokes, C. R. Velocity response of Petermann Glacier, northwest Greenland, to past and future calving events. Cryosphere 12, 3907–3921 (2018).
Alley, K. E., Scambos, T. A., Siegfried, M. R. & Fricker, H. A. Impacts of warm water on Antarctic ice shelf stability through basal channel formation. Nat. Geosci. 9, 290–293 (2016).
Glasser, N. F. & Scambos, T. A. A structural glaciological analysis of the 2002 Larsen B ice-shelf collapse. J. Glaciol. 54, 3–16 (2008).
Trusel, L. D., Frey, K. E., Das, S. B., Munneke, P. K. & van den Broeke, M. R. Satellite-based estimates of Antarctic surface meltwater fluxes. Geophys. Res. Lett. 40, 6148–6153 (2013).
Scambos, T. A., Hulbe, C., Fahnestock, M. & Bohlander, J. The link between climate warming and break-up of ice shelves in the Antarctic Peninsula. J. Glaciol. 46, 516–530 (2000).
Rack, W. & Rott, H. Pattern of retreat and disintegration of the Larsen B Ice Shelf, Antarctic Peninsula. Ann. Glaciol. 39, 505–510 (2004).
Howat, I. M., Porter, C., Smith, B. E., Noh, M. J. & Morin, P. The reference elevation model of Antarctica. Cryosphere 13, 665–674 (2019).
Shepherd, A., Wingham, D., Payne, T. & Skvarca, P. Larsen Ice Shelf has progressively thinned. Science 302, 856–859 (2003).
Warm ocean explains Antarctic ice shelf collapse. University of Cambridge (30 October 2003); https://www.geog.cam.ac.uk/research/projects/larseniceshelf/pressrelease.pdf
MacFerrin, M. et al. Rapid expansion of Greenland’s low-permeability ice slabs. Nature 573, 403–407 (2019).
Liu, H., Wang, L. & Jezek, K. C. Spatiotemporal variations of snowmelt in Antarctica derived from satellite scanning multichannel microwave radiometer and Special Sensor Microwave Imager data (1978–2004). J. Geophys. Res. Earth Surf. 111, F01003 (2006).
Bjørk, A. A., Kruse, L. M. & Michaelsen, P. B. Brief communication: Getting Greenland’s glaciers right—a new data set of all official Greenlandic glacier names. Cryosphere 9, 2215–2218 (2015).
Dominguez, R. IceBridge DMS L1B Geolocated and Orthorectified Images, Version 1 (NASA National Snow and Ice Data Center Distributed Active Archive Center, 2019); https://doi.org/10.5067/OZ6VNOPMPRJ0
Arvesen, J. C. & Dotson, R. C. Photogrammetric processing of IceBridge DMS imagery into high-resolution digital surface models (DEM and visible overlay). In: AGU Fall Meeting 2014 C21D–03 (AGU, 2014).
Dee, D. et al. The ERA-Interim Reanalysis: configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137, 553–597 (2011).
Lefebre, F., Gallée, H., van Ypersele, J.-P. & Greuell, W. Modeling of snow and ice melt at ETH Camp (West Greenland): a study of surface albedo. J. Geophys. Res. Atmos. 108, 4231 (2003).
Smith, L. C. et al. Direct measurements of meltwater runoff on the Greenland ice sheet surface. Proc. Natl Acad. Sci. USA 114, E10622–E10631 (2017).
Zuo, Z. & Oerlemans, J. Modelling albedo and specific balance of the Greenland ice sheet: calculations for the Søndre Strømfjord transect. J. Glaciol. 42, 305–317 (1996).
Forster, R. R. et al. Extensive liquid meltwater storage in firn within the Greenland ice sheet. Nat. Geosci. 7, 95–98 (2013).
Fettweis, X. et al. Reconstructions of the 1900–2015 Greenland ice sheet surface mass balance using the regional climate MAR model. Cryosphere 11, 1015–1033 (2017).
Förste, C. et al. The GeoForschungsZentrum Potsdam/Groupe de Recherche de Gèodésie Spatiale satellite-only and combined gravity field models: EIGEN-GL04S1 and EIGEN-GL04C. J. Geod. 82, 331–346 (2008).
Morlighem, M. et al. 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 (2017).
Washam, P., Nicholls, K. W., Münchow, A. & Padman, L. Summer surface melt thins Petermann Gletscher Ice Shelf by enhancing channelized basal melt. J. Glaciol. 65, 662–674 (2019).
Fountain, A. G. & Walder, J. S. Water flow through temperate glaciers. Rev. Geophys. 36, 299–328 (1998).
Vaughan, D. G. et al. Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica. J. Geophys. Res. Earth Surf. 117, F03012 (2012).
Martin, C. F. et al. Airborne Topographic Mapper Calibration Procedures and Accuracy Assessment Report No. NASA/TM–2012-215891 (NASA, 2012).
Irvine-Fynn, T. D. L., Hodson, A. J., Moorman, B. J., Vatne, G. & Hubbard, A. L. Polythermal glacier hydrology: a review. Rev. Geophys. 49, RG4002 (2011).
Cooper, M. G. et al. Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone. Cryosphere 12, 955–970 (2018).
Acknowledgements
We thank D. MacAyeal for helpful discussions about this manuscript. We also would like to acknowledge R. Fishman for providing imagery of the estuary, as well as M. Vogt of Volcano Heli, Iceland, for piloting the expedition to Petermann, enabling documentation of the estuary and providing imagery of the estuary. We also thank R. Boghosian for proofreading. We would have preferred to refer to the study site and features with Greenlandic/Indigenous names but were unable to find them; ‘Petermann’ was used as it is consistent with the literature39. Funding was provided by National Science Foundation grant 1644869 (A.L.B), the Old York Foundation (R.E.B.), the Heising-Simons Foundation grant PG009346_HSFOUND 2019-1160 (M.T.), the National Aeronautics and Space Administration Cryospheric Sciences Program grant 80NSSC19K0942 (L.C.S. and L.H.P.) and the National Aeronautics and Space Administration Modeling, Analysis and Prediction program award 16-MAP 16-0137 (P.M.A. and M.T.).
Author information
Authors and Affiliations
Contributions
A.L.B. contributed to conceptualization and investigation of the project, methodology, data analysis and visualization, and wrote the manuscript. All authors contributed to the manuscript. L.H.P. contributed to conceptualization and investigation of the project, methodology and data analysis, and provided resources. L.C.S. contributed to the conceptualization and investigation of the project. E.K. contributed to data analysis and visualization. P.M.A. and M.T. contributed data resources and to data analysis. R.E.B. contributed to conceptualization and investigation of the project.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Peer review information Primary Handling Editor: Thomas Richardson, in collaboration with the Nature Geoscience team. Nature Geoscience thanks Knut Christianson and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data
Extended Data Fig. 1 Ocean water atop the Petermann Ice Shelf after the melt season.
a Modèle Atmosphérique Regional v. 3.9 (MAR) average daily ice-surface melt averaged across the Petermann Ice Shelf from 2010 to 2017. The red dotted lines show earliest indication of seawater in the channel after the melt season as identified in high resolution WorldView-1 and WorldView-2 satellite imagery (Extended Data Table 2). b The first evidence of water atop the ice shelf was collected by WorldView-1 in 2013 (top). Note that break in the shadow cast by the ice-shelf terminus at the Petermann river channel confirms a direct connection between the ice shelf and the ocean. Multispectral WorldView-2 images collected in 2014 (middle) and 2016 (bottom) show water in the channel directly connected to the ocean and an absence of surface meltwater elsewhere on the ice shelf. Credit: b, (2013, 2014, 2016) DigitalGlobe, Inc.
Extended Data Fig. 2 Modelled melt and snowfall on Petermann Ice Shelf.
Top: MAR simulation of daily surface melt (blue) and snowfall (gray) averaged across the Petermann Ice Shelf from 2010 to 2017. Melt and snowfall are reported in millimeters water equivalent (mmwe), which is used to represent snow or ice mass in terms of its equivalent water volume. Bottom: estuary wetted widths measured at 25 m from calving front as in Extended Data Fig. 3 from 2010 to 2017. This demonstrates the lack of correlation between estuary widening and surface runoff.
Extended Data Fig. 3 Evidence for change at the mouth of the estuary.
a Location of wetted width measurements at 1 km increments along the Petermann river set against pan-chromatic WorldView-2 image (30 August 2018). Blue line denotes the maximum extent of sea ice found in the channel, (24 July 2018). Purple line denotes the maximum extent of the longitudinal fracture (25 July 2017). Red box shows the location of Extended Data Fig. 3b. b The mouth of the Petermann estuary widened from 2012 (left) to 2018 (right). Left panel: 2012 image with river widths shown as colored lines at 25 m increments from the ice-shelf front (QuickBird image July 19th). Right panel: 2018 image with river widths at 25m increments as in left panel. The estuary is approximately three times wider in 2018. c Wetted width measurements along channel from 2010 to 2018. The channel widens at the mouth of the estuary and within 2 km from the ice-shelf front. Width measurements (points) and trendlines are colored by locations marked in Extended Data Fig. 3a,b. Fracture growth and flow reversal evidence are coincident with this widening as shown in a. Credit: a,b (left): (2012, 2018) DigitalGlobe, Inc.
Extended Data Fig. 4 Additional evidence for the Ryder Ice Shelf estuary.
(a) The Ryder estuary in a WorldView-2 image collected on 25 August 2014. Red boxes mark the location of (b) and (c), and gold star marks the approximate location of the 2019 estuary (Fig. 2c). (b) Detailed image of the downstream portion of the estuary shows water in the channel directly connected to the ocean and an absence of surface meltwater elsewhere on the ice shelf. (c) Detailed image of the upstream portion of the estuary shows water in the channel directly connected to ocean water in the rift and an absence of surface meltwater elsewhere on the ice shelf. Credit: (2014) DigitalGlobe, Inc.
Extended Data Fig. 5 Detail of longitudinal fractures at the Petermann estuary.
WorldView imagery at the Petermann estuary from which fractures were digitized (Fig. 2a). Red boxes show location of detail views. Fractures are identified as dark linear features along the bottom of the channel. Images collected on 14 July 2014; 17 July 2015; 15 July 2016; and 25 July 2017. Credit: (2014, 2015, 2016, 2017) DigitalGlobe Inc.
Supplementary information
Supplementary Data 1
MAR outputs of runoff, snowfall and melt in millimeters water equivalent (mmwe). Also available for download in .mat and NetCDF at: http://wonder.ldeo.columbia.edu/data/publicationData/Boghosian/Estuary/
Supplementary Data 2
Digitized river widths and fractures. All original shapefiles are available at: http://wonder.ldeo.columbia.edu/data/publicationData/Boghosian/Estuary/
Rights and permissions
About this article
Cite this article
Boghosian, A.L., Pitcher, L.H., Smith, L.C. et al. Development of ice-shelf estuaries promotes fractures and calving. Nat. Geosci. 14, 899–905 (2021). https://doi.org/10.1038/s41561-021-00837-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41561-021-00837-7