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Roughness of a subglacial conduit under Hansbreen, Svalbard


Hydraulic roughness exerts an important but poorly understood control on water pressure in subglacial conduits. Where relative roughness values are <5%, hydraulic roughness can be related to relative roughness using empirically-derived equations such as the Colebrook–White equation. General relationships between hydraulic roughness and relative roughness do not exist for relative roughness >5%. Here we report the first quantitative assessment of roughness heights and hydraulic diameters in a subglacial conduit. We measured roughness heights in a 125 m long section of a subglacial conduit using structure-from-motion to produce a digital surface model, and hand-measurements of the b-axis of rocks. We found roughness heights from 0.07 to 0.22 m and cross-sectional areas of 1–2 m2, resulting in relative roughness of 3–12% and >5% for most locations. A simple geometric model of varying conduit diameter shows that when the conduit is small relative roughness is >30% and has large variability. Our results suggest that parameterizations of conduit hydraulic roughness in subglacial hydrological models will remain challenging until hydraulic diameters exceed roughness heights by a factor of 20, or the conduit radius is >1 m for the roughness elements observed here.

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This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (, which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
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Correspondence: Ken Mankoff <>
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Aberle J and Nikora V (2006) Statistical properties of armored gravel bed surfaces. Water Resour. Res., 42(11) (doi: 10.1029/2005WR004674)
Banwell AF, MacAyeal DR and Sergienko OV (2013) Break-up of the Larsen B ice shelf triggered by chain-reaction drainage of Supraglacial Lakes. Geophys. Res. Lett., 40(22), 58725876 (doi: 10.1002/2013GL057694)
Bertin S and Freidrich H (2014) Measurement of gravel-bed topography: evaluation study applying statistical roughness analysis. J. Hydraulic Eng., 140(3), 269279 (doi: 10.1061/(ASCE)HY.1943-7900.0000823)
Bindschadler RA (1983) The importance of pressurized subglacial water in separation and sliding at the glacier bed. J. Glaciol., 29(101), 319
Chikita KA, Kaminaga R, Kudo I, Wada T and Kim Y (2010) Parameters determining water temperature of a proglacial stream: the Phelan Creek and the Gulkana Glacier, Alaska. River Res. Appl., 26, 9951004
Covington MD, Luhmann AJ, Gabrovšek F, Saar MO and Wicks CM (2011) Mechanisms of heat exchange between water and rock in karst conduits. Water Resour. Res., 47(W10514) (doi: 10.1029/2011WR010683)
Crosby C and 6 others (2011) Points2Grid: A Local Gridding Method for DEM Generation from Lidar Point Cloud Data. [Software]
Cuffey KM and Paterson WSB (2010) The physics of glaciers, 4th edn. Academic Press
Curl RL (1974) Deducing flow velocity in cave conduits from scallops. Natl. Speleol. Soc. Bull., 36(2), 15, (Errata: ibid. Vol. 36, No. 3, p. 22)
Fonstad MA, Dietrich JT, Courville BC, Jensen JL and Carbonneau PE (2013) Topographic structure from motion: a new development in photogrammetric measurement. Earth Surf. Process. Landforms, 38, 421430 (doi: 10.1002/esp.3366)
Gulley JD (2009) Structural control of englacial conduits in the temperate Matanuska Glacier, Alaska, USA. J. Glaciol., 55(192), 681690
Gulley JD and 5 others (2012) The effect of discrete recharge by moulins and heterogeneity in flow-path efficiency at glacier beds on subglacial hydrology. J. Glaciol., 58(211), 926940 (doi: 10.3189/2012JoG11J189)
Gulley JD and 5 others (2014) Large values of hydraulic roughness in subglacial conduits during conduit enlargement: implications for modeling conduit evolution. Earth Surf. Process. Landforms, 39(3), 296310 (doi: 10.1002/esp.3447)
Hewitt IJ (2011) Modelling distributed and channelized subglacial drainage: the spacing of channels. J. Glaciol., 57(202)
Hodge RA, Brasington J and Richards K (2009) Analysing laser-scanned digital terrain models of gravel bed surfaces: linking morphology to sediment transport processes and hydraulics. Sedimentology, 56(7), 20242043 (doi: 10.1111/j.1365-3091.2009.01068.x)
Isenko E, Naruse R and Mavlyudov B (2005) Water temperature in englacial and supraglacial channels: change along the flow and contribution to ice melting on the channel wall. Cold Reg. Sci. Technol., 42, 5362 (doi: 10.1016/j.coldregions.2004.12.003)
James MR and Robson S (2012) Straightforward reconstruction of 3D surfaces and topography with a camera: accuracy and geoscience applications. J. Geophys. Res., 117(F03017) (doi: 10.1029/2011JF002289)
Jarrett RD (1984) Hydraulics of high-gradient streams. J. Hydraulic Eng., 110(11), 15191539 (doi: 10.1061/(ASCE)0733-9429(1984)110:11(1519))
Jezek KC, Wu X, Paden J and Leuschen C (2013) Radar mapping of Isunguata Sermia, Greenland. J. Glaciol., 59(218), 1135 (doi: 10.3189/2013JoG12J248)
Kolmogorov AN (1991) The local structure of turbulence in incompressible viscous fluid for very large Reynolds numbers. Proc. Math. Phys. Sci., 434(1890), 913.
Liestøl O (1956) Glacier Dammed Lakes in Norway, vol. 81. Fabritius & Sønners Forlag, Oslo
Limerinos J (1970) Determination of the manning coefficient from measured bed roughness in natural channels. United States Government Printing Office, geological survey water-supply paper 1898-b edition, Washington, DC
Mankoff KD and Russo TA (2013) The Kinect: a low-cost, high-resolution, short-range, 3D camera. Earth Surf. Process. Landforms, 38(9), 926936 (doi: 10.1002/esp.3332)
Mankoff KD and 5 others (2016) Structure and dynamics of a subglacial discharge plume in a Greenlandic fjord. J. Geophys. Res.: Oceans, 121 (doi: 10.1002/2016JC011764)
Moody LF (1944) Friction factors for pipe flow. Trans. A.S.M.E., 66(8), 671684
Munson BR, Young DF, Okiishi TH and Heubsch WW (2009) Fundamentals of fluid mechanics, 6th edn. John Wiley & Sons, Inc.
Nienow PW, Sharp M and Willis IC (1998) Seasonal changes in the morphology of the subglacial drainage system, Haut Glacier d'Arolla, Switzerland. Earth Surf. Process. Landforms, 23(9), 825843 (doi: 10.1002/(SICI)1096-9837(199809)23:9<825::AID-ESP893>3.0.CO;2-2)
Nikora VI and Walsh J (2004) Water-worked gravel surfaces: high-order structure functions at the particle scale. Water Resour. Res., 40(12) (doi: 10.1029/2004WR003346)
Nikora VI, Goring DG and Biggs BJF (1998) On gravel-bed roughness characterization. Water Resour. Res., 34(3), 517527 (doi: 10.1029/97WR02886)
Nikuradse J (1950) Laws of flow in rough pipes. Technical Memorandum 1292, National Advisory Committee for Aeronautics (NACA), translation of ‘Strömungsgesetze in rauhen Rohren.’ 1933
Nye JF (1976) Water flow in glaciers: jökulhlaups, tunnels and veins. J. Glaciol., 17(76), 181207
Perol T, Rice JR, Platt JD and Suckale J (2015) Subglacial hydrology and ice stream margin locations. J. Geophys. Res.: Earth Surf., 120(7), 13521368 (doi: 10.1002/2015JF003542)
Powell M (2014) Flow resistance in gravel-bed rivers: progress in research. Earth-Sci. Rev., 136, 301338 (doi: 10.1016/j.earscirev.2014.06.001)
Röthlisberger H (1972) Water pressure in intra- and subglacial channels. J. Glaciol., 11(62), 177203
Rusu RB and Cousins S (2011) 3D is here: Point Cloud Library (PCL). In IEEE International Conference on Robotics and Automation (ICRA), Shanghai, China
Schoof CG (2010) Ice-sheet acceleration driven by melt supply variability. Nature, 468(7325), 803806 (doi: 10.1038/nature09618)
Shreve RL (1972) Movement of water in glaciers. J. Glaciol., 11(62), 205214
Smart G, Aberle J, Duncan M and Walsh J (2004) Measurement and analysis of alluvial bed roughness/mesure et analyse de la rugosité de lit d'alluvion. J. Hydraulic Res., 42(3), 227237 (doi: 10.1080/00221686.2004.9641191)
Smart GM, Duncan MJ and Walsh JM (2002) Relatively rough flow resistance equations. J. Hydraulic Eng., 128, 568578 (doi: 10.1061/(ASCE)0733-9429(2002)128:6(568))
Smith MW (2014) Roughness in the earth sciences. Earth-Sci. Rev., 136, 202225 (doi: 10.1016/j.earscirev.2014.05.016)
Westoby MJ, Brasington J, Glasser NF, Hambrey MJ and Reynolds JM (2012) ‘Structure-from-Motion’ photogrammetry: a low-cost, effective tool for geoscience applications. Geomorphology, 179, 300314 (doi: 10.1016/j.geomorph.2012.08.021)
Whelan T and 5 others (2012) Kintinuous: spatially extended KinectFusion. In RSS Workshop on RGB-D: Advanced Reasoning with Depth Cameras, Sydney, Australia
Wolman MG (1954) A method of sampling coarse river-bed material. Trans. Am. Geophys. Union, 35(6), 951956
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