Substantial export of suspended sediment to the global oceans from glacial erosion in Greenland

Abstract

Limited measurements along Greenland’s remote coastline hamper quantification of the sediment and associated nutrients draining the Greenland ice sheet, despite the potential influence of river-transported suspended sediment on phytoplankton blooms and carbon sequestration. Here we calibrate satellite imagery to estimate suspended sediment concentration for 160 proglacial rivers across Greenland. Combining these suspended sediment reconstructions with numerical calculations of meltwater runoff, we quantify the amount and spatial pattern of sediment export from the ice sheet. We find that, although runoff from Greenland represents only 1.1% of the Earth’s freshwater flux, the Greenland ice sheet produces approximately 8% of the modern fluvial export of suspended sediment to the global ocean. Sediment loads are highly variable between rivers, consistent with observed differences in ice dynamics and thus with control by glacial erosion. Rivers that originate from deeply incised, fast-moving glacial tongues form distinct sediment-export hotspots: just 15% of Greenland’s rivers transport 80% of the total sediment load of the ice sheet. We conclude that future acceleration of melt and ice sheet flow may increase sediment delivery from Greenland to its fjords and the nearby ocean.

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Figure 1: Map of long-term proglacial riverine suspended sediment concentration (SSC) for 160 selected rivers along the Greenland ice sheet margin.
Figure 2: Maps of the mean suspended sediment concentration (SSC) derived from the Landsat7 image analysis over 1999–2014.
Figure 3: Glacial dynamics control variability in suspended sediment delivery.

References

  1. 1

    Walling, D. E. Human impact on land–ocean sediment transfer by the world’s rivers. Geomorphology 79, 192–216 (2006).

    Article  Google Scholar 

  2. 2

    Syvitski, J. P. M. & Kettner, A. J. Sediment flux and the Anthropocene. Phil. Trans. R. Soc. A. 369, 957–975 (2011).

    Article  Google Scholar 

  3. 3

    Syvitski, J. P. M., Kettner, A. J., Overeem, I., Brakenridge, R. & Cohen, S. Latitudinal Controls on Stratigraphic Models and Sedimentary Concepts (SEPM Special Publication, in the press, 2017).

    Google Scholar 

  4. 4

    Arrigo, K. R. Carbon cycle: marine manipulations. Nature 450, 491–492 (2007).

    Article  Google Scholar 

  5. 5

    Bhatia, M. P. et al. Greenland meltwater as a significant and potentially bioavailable source of iron to the ocean. Nat. Geosci. 6, 274–278 (2013).

    Article  Google Scholar 

  6. 6

    Sanders, R. et al. The biological carbon pump in the North Atlantic. Prog. Oceanogr. 129, 200–218 (2014).

    Article  Google Scholar 

  7. 7

    Hawkings, J. R. et al. The effect of warming climate on nutrient and solute export from the Greenland ice sheet. Geochem. Perspect. Lett. 1, 94–104 (2015).

    Article  Google Scholar 

  8. 8

    Hallet, B., Hunter, L. & Bogen, J. Rates of erosion and sediment evacuation by glaciers: a review of field data and their implications. Glob. Planet. Change 12, 213–235 (1996).

    Article  Google Scholar 

  9. 9

    Koppes, M. N. & Montgomery, D. The relative efficacy of fluvial and glacial erosion over modern to orogenic timescales. Nat. Geosci. 2, 644–647 (2009).

    Article  Google Scholar 

  10. 10

    Smith, R. W., Bianchi, T. S., Allison, M., Savage, C. & Galy, V. High rates of organic carbon burial in fjord sediments globally. Nat. Geosci. 8, 450–453 (2015).

    Article  Google Scholar 

  11. 11

    Shepherd, A. et al. Reconciled estimate of ice-sheet mass balance. Science 338, 1183–1189 (2015).

    Article  Google Scholar 

  12. 12

    Enderlin, E. et al. An improved mass balance for the Greenland ice sheet. Geophys. Res. Lett. 3, 866–872 (2014).

    Article  Google Scholar 

  13. 13

    Khan, S. et al. Sustained mass loss of the northeast Greenland ice sheet triggered by regional warming. Nat. Clim. Change 4, 292–299 (2015).

    Article  Google Scholar 

  14. 14

    Howat, I., Joughin, I. & Scambos, T. A. Rapid changes in ice discharge from Greenland outlet glaciers. Science 315, 1559–1561 (2007).

    Article  Google Scholar 

  15. 15

    Moon, T., Joughin, I., Smith, B. & Howat, I. 21st century evolution of Greenland outlet velocities. Science 336, 576–578 (2012).

    Article  Google Scholar 

  16. 16

    van der Broeke, M. et al. On the recent contribution of the Greenland ice sheet to sea level change. Cryosphere 10, 1933–1946 (2016).

    Article  Google Scholar 

  17. 17

    Hudson, B. et al. MODIS observed increase in duration and spatial extent of sediment plumes in Greenland fjords. Cryosphere 8, 1161–1176 (2014).

    Article  Google Scholar 

  18. 18

    Hasholt, B. et al. Sediment transport to the Arctic Ocean and adjoining cold oceans. Nord. Hydrol. 37, 413–432 (2006).

    Article  Google Scholar 

  19. 19

    Ettema, J. et al. Climate of the Greenland ice sheet using a high-resolution climate model—Part 1: evaluation. Cryosphere 4, 511–527 (2010).

    Article  Google Scholar 

  20. 20

    Noël, B. et al. Evaluation of the updated regional climate model RACMO2.3: summer snowfall impact on the Greenland ice sheet. Cryosphere 9, 1831–1844 (2015).

    Article  Google Scholar 

  21. 21

    Morlighem, M., Rignot, E. & Mouginot, J. Deeply incised submarine glacial valleys beneath the Greenland ice sheet. Nat. Geosci. 7, 18–22 (2014).

    Article  Google Scholar 

  22. 22

    Howat, I., Negrete, A. & Smith, B. The Greenland Ice Mapping Project (GIMP) land classification and surface elevation datasets. Cryosphere 8, 1509–1518 (2014).

    Article  Google Scholar 

  23. 23

    Joughin, I., Smith, B., Howat, I. M., Scambos, T. & Moon, T. Greenland flow variability from ice-sheet-wide velocity mapping. J. Glaciol. 56, 415–430 (2010).

    Article  Google Scholar 

  24. 24

    Escher, J. C. & Pulvertaft, T. C. R. Geological map of Greenland 1: 2500000 (Geological Survey of Denmark, 1995).

  25. 25

    Arrigo, K. R. et al. Melting glaciers stimulate large summer phytoplankton blooms in southwest Greenland waters. Geophys. Res. Lett. 44, 6278–6285 (2017).

    Article  Google Scholar 

  26. 26

    Meire, L. et al. Glacial meltwater and primary production are drivers of strong CO2 uptake in fjord and coastal waters adjacent to the Greenland ice sheet. Biogeosciences 12, 2347–2363 (2015).

    Article  Google Scholar 

  27. 27

    Petrenko, D., Podznyakov, D. J., Johannessen, J., Counillion, F. & Sychov, V. Satellite-derived multi-year trend in primary production in the Arctic Ocean. Int. J. Remote Sens. 34, 3903–3937 (2013).

    Article  Google Scholar 

  28. 28

    Sepulveda, J., Pantoja, S. & Hughen, K. A. Sources and distribution of organic matter in northern Patagonia fjords, Chile (44–46° S): a multi-tracer approach for carbon cycling. Cont. Shelf. Res. 31, 315–329 (2011).

    Article  Google Scholar 

  29. 29

    Dürr, H. H. et al. Worldwide typology of nearshore coastal systems: defining the estuarine filter of river inputs to the oceans. Estuar. Coast. 34, 441–458 (2011).

    Article  Google Scholar 

  30. 30

    Mankoff, K. D. et al. Structure and dynamics of a subglacial discharge plume in a Greenlandic fjord. J. Geophys. Res. 121, 8670–8688 (2016).

    Article  Google Scholar 

  31. 31

    Chu, V. W., Smith, L. C., Rennermalm, A., Forster, R. & Box, J. E. Hydrological controls on coastal suspended sediment plumes around the Greenland ice sheet. Cryosphere 6, 1–19 (2012).

    Article  Google Scholar 

  32. 32

    Hasholt, B., Mikkelsen, A. B., Nielsen, M. H. & Larsen, M. Observations of runoff and sediment and dissolved loads from the Greenland ice sheet at Kangerlussuaq, West Greenland, 2007 to 2010. Z. Geomorphol. 57 (suppl.), 3–27 (2013).

    Article  Google Scholar 

  33. 33

    Bartholomew, I. et al. Supraglacial forcing of subglacial drainage in the ablation zone of the Greenland ice sheet. Geophys. Res. Lett. 38, 1–5 (2011).

    Article  Google Scholar 

  34. 34

    Woodcock, C. E. et al. Free access to Landsat imagery. Science 320, 1011 (2008).

    Article  Google Scholar 

  35. 35

    Chander, G., Markham, B. L. & Helder, D. Summary of current radiometric calibration coefficients for Landsat MSS, TM, ETM +, and EO-1 ALI sensors. Remote Sens. Environ. 113, 893–903 (2009).

    Article  Google Scholar 

  36. 36

    Lewis, S. M. & Smith, L. C. Hydrologic drainage of the Greenland ice sheet. Hydrol. Process. 23, 2004–2011 (2009).

    Article  Google Scholar 

  37. 37

    Cuffey, K. M. & Paterson, W. S. B. The Physics of Glaciers 4th edn, 693 (Elsevier, 2010).

    Google Scholar 

  38. 38

    Tarboton, D. A new method for the determination of flow directions and contributing areas in grid digital elevation models. Wat. Resour. Res. 33, 309–319 (1997).

    Article  Google Scholar 

  39. 39

    Yang, K., Smith, L. C., Chu, V., Gleason, C. & Li, M. A caution on the use of surface digital elevation models to simulate supraglacial hydrology of the Greenland ice sheet. IEEE J-STARS 8, 5212–5224 (2015).

    Google Scholar 

  40. 40

    Ettema, J., van den Broeke, M. R., van Meijgaard, E. & van den Berg, W. J. Climate of the Greenland ice sheet using a high-resolution climate model—Part 2: near-surface climate and energy balance. Cryosphere 4, 529–544 (2010).

    Article  Google Scholar 

  41. 41

    Noël, B. et al. Summer snowfall on the Greenland ice sheet: a study with the updated regional climate model RACMO2.3. Cryosphere 9, 1177–1208 (2015).

    Article  Google Scholar 

  42. 42

    Bamber, J., van den Broeke, J. M. R., Ettema, J., Lenaerts, J. & Rignot, E. Recent large increases in freshwater fluxes from Greenland into the North Atlantic. Geophys. Res. Lett. 39, L19501 (2012).

    Article  Google Scholar 

  43. 43

    Harper, J., Humphrey, N., Pfeffer, W. T., Brown, J. & Fettweis, X. Greenland ice-sheet contribution to sea-level rise buffered by meltwater storage in firn. Nature 491, 240–243 (2012).

    Article  Google Scholar 

  44. 44

    Janssens, I. & Huybrechts, P. The treatment of meltwater retention in massbalance parameterizations of the Greenland ice sheet. Ann. Glaciol. 31, 133–140 (2000).

    Article  Google Scholar 

  45. 45

    van Angelen, J., Lenaerts, J., van den Broeke, M. R., Fettweiss, X. & van Meijgaard, E. Rapid loss of firn pore space accelerates 21st century Greenland mass loss. Geophys. Res. Lett. 40, 2109–2113 (2013).

    Article  Google Scholar 

  46. 46

    Overeem, I. et al. River inundation suggests ice sheet runoff variations. J. Glaciol. 61, 776–788 (2015).

    Article  Google Scholar 

  47. 47

    Hallet, B. A theoretical model of glacial abrasion. J. Glaciol. 23, 39–50 (1979).

    Article  Google Scholar 

  48. 48

    Goudie, A. S. The Schmidt hammer in Geomorphological research. Prog. Phys. Geogr. 30, 703–718 (2006).

    Article  Google Scholar 

  49. 49

    Dowdeswell, J. A. & Murray, T. in Glacimarine Environments: Processes and Sediments Vol. 53 (eds Dowdeswell, J. A. & Scourse, J. D.) 1121–1137 (Geological Society Special Publication, 1990).

    Google Scholar 

  50. 50

    Andrews, J. T., Milliman, J. D., Jennings, A. E., Rynes, N. & Dwyer, J. Sediment thicknesses and holocene glacial marine sedimentation rates in three East Greenland Fjords (ca. 68° N). J. Geol. 102, 669–683 (1994).

    Article  Google Scholar 

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Acknowledgements

I.O. and B.H. were supported by NSF-OPP award ARC-0909349. M.R.v.d.B. and B.P.Y.N. received funding from NWO/NPP and the Netherlands Earth System Science Centre (NESSC). We thank I. Joughin and E. Enderlin for data sharing. S. Frye, NASA-GSFC, enabled acquisition of ALI imagery.

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I.O. and B.H. designed the study and implemented the analysis. J.P.M.S., B.H., A.B.M. M.R.v.d.B., M.M. and B.P.Y.N. contributed to data analysis. I.O. authored the manuscript, all co-authors contributed to the writing.

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Correspondence to I. Overeem.

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Overeem, I., Hudson, B., Syvitski, J. et al. Substantial export of suspended sediment to the global oceans from glacial erosion in Greenland. Nature Geosci 10, 859–863 (2017). https://doi.org/10.1038/ngeo3046

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