Skip to main content
×
×
Home

Glacier motion dominated by processes deep in underlying till

  • M. Truffer (a1), W. D. Harrison (a1) and K. A. Echelmeyer (a1)
Abstract

Black Rapids Glacier is a 40 km long surge-type glacier in the central Alaska Range. In spring 1997 a wireline drill rig was set up at a location where the measured surface velocities are high and seasonal and annual velocity variations are large. The drilling revealed a layer of subglacial “till”, up to 7 m thick, that is believed to be water-saturated. At one location a string of instruments, containing three dual-axis tiltmeters and one piezometer, was successfully introduced into the till. The tiltmeters monitored the inclination of the borehole at the ice–till interface and at 1 and 2 m into the till, for 410 days. They showed that no significant deformation occurred in the upper 2 m of the till layer, and no significant amount of the basal motion was due to sliding of the ice over the till. The measured surface velocity at the drill site is about 60 m a−1, of which 20–30 m a can be accounted for by ice deformation. Almost the entire amount of basal motion, 30–40 m a−1, was taken up at a depth of > 2 m in the till, possibly in discrete shear layers, or as sliding of till over the underlying bedrock. We propose that the large-scale mobilization of such till layers is a key factor in initiating glacier surges.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Glacier motion dominated by processes deep in underlying till
      Available formats
      ×
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Glacier motion dominated by processes deep in underlying till
      Available formats
      ×
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Glacier motion dominated by processes deep in underlying till
      Available formats
      ×
Copyright
References
Hide All
Alley, R. B. 1989. Water-pressure coupling of sliding and bed deformation: II. Velocity–depth profiles. J. Glaciol., 35(119), 119129.
Alley, R. B. 1991. Deforming-bed origin for southern Laurentide till sheets? J. Glaciol., 37(125), 6776.
Alley, R. B., Blankenship, D. D., Bentley, C. R. and Rooney, S. T.. 1986. Deformation of till beneath Ice Stream B, West Antarctica. Nature, 322(6074), 5759.
Astakhov, V. I., Kaplyanskaya, F. A. and Tarnogradskiy, V. D.. 1996. Pleistocene permafrost of west Siberia as a deformable glacier bed. Permafrost and Periglacial Processes, 7, 165191.
Bennett, M. R. and Glasser, N. F.. 1996. Glacial geology: ice sheets and landforms. Chichester, etc., John Wiley & Sons.
Blake, E. W. 1992. The deforming bed beneath a surge-type glacier: measurement of mechanical and electrical properties. (Ph. D. thesis, University of British Columbia.)
Blake, E., Clarke, G. K. C. and Gérin, M. C.. 1992. Tools for examining subglacial bed deformation. J. Glaciol., 38(130), 388396.
Blake, E. W., Fischer, U. H. and Clarke, G. K. C.. 1994. Direct measurement of sliding at the glacier bed. J. Glaciol., 40(136), 595599.
Blankenship, D. D., Bentley, C. R., Rooney, S. T. and Alley, R. B.. 1986. Seismic measurements reveal a saturated porous layer beneath an active Antarctic ice stream. Nature, 322(6074), 5457.
Boulton, G. S. and Hindmarsh, R. C. A.. 1987. Sediment deformation beneath glaciers: rheology and geological consequences. J. Geophys. Res., 92(B9), 90599082.
Boulton, G. S. and Jones, A. S.. 1979. Stability of temperate ice caps and ice sheets resting on beds of deformable sediment. J. Glaciol., 24(90), 2943.
Bowles, J. E. 1992. Engineering properties of soils and their measurement. Fourth edition. New York, McGraw-Hill Inc.
Brown, N. E., Hallet, B. and Booth, D. B.. 1987. Rapid soft bed sliding of the Puget glacial lobe. J. Geophys. Res., 92(B9), 89858997.
Brugman, M. M. 1986. Water flow at the base of a surging glacier. (Ph.D. thesis, California Institute of Technology, Pasadena, California.)
Clarke, G. K. C. 1987. Subglacial till: a physical framework for its properties and processes. J. Geophys. Res., 92(B9), 90239036.
Clarke, G. K. C., Collins, S. G. and Thompson, D. E.. 1984. Flow, thermal structure, and subglacial conditions of a surge-type glacier. Can. J. Earth Sa., 21(2), 232240.
Clayton, L., Mickelson, D. M. and Attig, J. W.. 1989. Evidence against pervasively deformed bed material beneath rapidly moving lobes of the southern Laurentide ice sheet. Sediment. Geol., 62(3–4), 203208.
Cuffey, K. and Alley, R. B.. 1996. Is erosion by deforming subglacial sediments significant? (Toward till continuity.) Ann. Glaciol., 22, 1724.
De Marsily, G. 1986. Quantitative hydrogeology. San Diego, CA, Academic Press Inc.
Echelmeyer, K. and Zhongxiang, Wang. 1987. Direct observation of basal sliding and deformation of basal drift at sub-freezing temperatures. J. Glaciol, 33(113), 8398.
Engelhardt, H. and Kamb, B.. 1998. Basal sliding of Ice Stream B, West Antarctica. J. Glaciol., 44(147), 223230.
Engelhardt, H. F., Harrison, W. D. and Kamb, B.. 1978. Basal sliding and conditions at the glacier bed as revealed by bore-hole photography. J. Glaciol., 20(84), 469508.
Engelhardt, H., Humphrey, N., Kamb, B. and Fahnestock, M.. 1990. Physical conditions at the base of a fast moving Antarctic ice stream. Science, 248(4951), 5759.
Fischer, U. H. and Clarke, G. K. C.. 1994. Ploughing of subglacial sediment. J. Glaciol, 40(134), 97106.
Fischer, U. H., Iverson, N. R., Hanson, B., Hooke, R. LeB. and Jansson, P.. 1998. Estimation of hydraulic properties of subglacial till from ploughmeter measurements. J. Glaciol., 44(148), 517522.
Hallet, B., Hunter, L. E. and Bogen, J.. 1996. Rates of erosion and sediment evacuation by glaciers: a review of field data and their implications. Global and Planetary Change, 12(1–4), 213235.
Hamilton, G. S. and Dowdeswell, J. A.. 1996. Controls on glacier surging in Svalbard. J. Glaciol., 42(140), 157168.
Harrison, W. D. and Kamb, B.. 1973. Glacier bore-hole photography. J. Glaciol., 12(64), 129137.
Harrison, W. D., Kamb, B. and Engelhardt, H.. 1986. Morphology and motion at the bed of a surge-type glacier. Abstract. Eidg. Tech. Hochschule, Zürich. Versuchsanst. Wasserbau, Hydrol. Glaziol. Mitt. 90, 5556.
Harrison, W. D., Echelmeyer, K. A., Chacho, E. F., Raymond, C. F. and Benedict, R. J.. 1994. The 1987–88 surge of West Fork Glacier, Susitna Basin, Alaska, U.S.A. J. Glaciol., 40(135), 241254.
Heinrichs, T. A., Mayo, L. R., Echelmeyer, K. A. and Harrison, W. D.. 1996. Quiescent-phase evolution of a surge-type glacier: Black Rapids Glacier, Alaska, U.S.A. J. Glaciol, 42(140), 110122.
Hiemstra, J. F. and van der Meer, J. J. M.. 1997. Pore-water controlled grain fracturing as an indicator for subglacial shearing in tills. J. Glaciol., 43(145), 446454.
Hindmarsh, R. C. A. 1996. Sliding of till over bedrock: scratching, polishing, comminution and kinematic-wave theory. Ann. Glaciol., 22, 4147.
Hooke, R. LeB., Hanson, B., Iverson, N. R., Jansson, P. and Fischer, U. H.. 1997. Rheology of till beneath Storglaciären, Sweden. J. Glaciol., 43(143), 172179.
Humphrey, N. F. and Raymond, C. F.. 1994. Hydrology, erosion and sediment production in a surging glacier: Variegated Glacier, Alaska, 1982– 83. J. Glaciol., 40(136), 539552.
Iverson, N. R., Baker, R. W. and Hooyer, T. S.. 1997. A ring-shear device for the study of till deformation: tests on tills with contrasting clay contents. Quat. Sci. Rev., 16(9), 10571066.
Iverson, N. R., Hooyer, T. S. and Baker, R. W.. 1998. Ring-shear studies of till deformation: Coulomb-plastic behavior and distributed strain in glacier beds. J. Glaciol, 44(148), 634642.
Iverson, N. R., Baker, R. W., Hooke, R. LeB., Hanson, B. and Jansson, P.. 1999. Coupling between a glacier and a soft bed. I. A relation between effective pressure and local shear stress determined from till elasticity. J. Glaciol, 45(149), 3140.
Julien, P. Y. 1995. Erosion and sedimentation. Cambridge, Cambridge University Press.
Kamb, B. 1987. Glacier surge mechanism based on linked cavity configuration of the basal water conduit system. J. Geophys. Res, 92(B9), 90839100.
Kamb, B. 1991. Rheological nonlinearity and flow instability in the deforming bed mechanism of ice stream motion. J. Geophys. Res., 96(B10), 16,58516,595.
Kamb, B. and Echelmeyer, K. A.. 1986. Stress-gradient coupling in glacier flow: I. Longitudinal averaging of the influence of ice thickness and surface slope. J. Glaciol, 32(111), 267284.
Kamb, B. and 7 others. 1985. Glacier surge mechanism: 1982–1983 surge of Variegated Glacier, Alaska. Science, 227(4686), 469479.
Knight, P. G. 1999. Glaciers. Cheltenham, Stanley Thornes (Publishers) Ltd.
Krenke, A. N. and Rototayev, K. P.. 1973. A surge of the Kolka Glacier and its hydrometeorological consequences. International Association of Hydrological Sciences Publication 107 (Symposium at Banff 1972 — The Role of Snow and Ice in Hydrology), Vol. 2, 11601171.
Lambe, T. W. and Whitman, R. V.. 1979. Soil mechanics. New York, etc., John Wiley and Sons.
Mandl, G., dejong, L. N. J. and Maltha, A.. 1977. Shear zones in granular material — an experimental study of their structure and mechanical genesis. Rock Mech., 9, 95144.
Menzies, J. and Shilts, W. W.. 1996. Subglacial environments. In Menzies, J., ed. Past glacial environments — sediments, forms and techniques. Glacial environments. Vol. 2 . Oxford, etc., Butterworth-Heinemann, 15136.
Mickelson, D. M., Clayton, L., Fullerton, D. S. and Borns, H. W. Jr. 1983. The Late Wisconsin glacial record of the Laurentide ice sheet in the United States. In Wright, H. E. Jr, ed. Late-Quaternary environments of the United States. Vol. 1. Porter, S.C., ed. The Late Pleistocene. Minneapolis, MN, University of Minnesota Press, 337.
Nolan, M. and Echelmeyer, K.. 1999a. Seismic detection of transient changes beneath Black Rapids Glacier, Alaska, U.S.A.: I. Techniques andobservations. J. Glaciol., 45(149), 119131.
Nolan, M. and Echelmeyer, K.. 1999b. Seismic detection of transient changes beneath Black Rapids Glacier, Alaska, U.S.A.: II. Basal morphology and processes. J. Glaciol., 45(149), 132146.
Raymond, C. F. and Harrison, W. D.. 1988. Evolution of Variegated Glacier, Alaska, U.S.A., prior to its surge. J. Glaciol., 34(117), 154169.
Truffer, M., Motyka, R. J., Harrison, W. D., Echelmeyer, K. A., Fisk, B. and Tulaczyk, S.. 1999. Subglacial drilling at Black Rapids Glacier, Alaska, U.S.A.: drilling method and sample descriptions. J. Glaciol., 45(151), 495505.
Tulaczyk, S. 1999. Ice sliding over weak, fine-grained tills: dependence of ice–till interactions on till granulometry. In Mickelson, D. M. and Attig, J. V., eds. Glacial processes: past and present. Boulder, CO, Geological Society of America, 159177. (Special Paper 337.)
Tulaczyk, S. M., Kamb, B. and Engelhardt, H. F.. 2000. Basal mechanics of Ice Stream B, West Antarctica. I. Till mechanics. J. Geophys. Res, 105(B1), 463481.
Van der Wateren, F. M. 1995. Processes of glaciotectonism. In Menzies, J., ed. Modern glacial environments —processes, dynamics and sediments. Glacial environments. Vol. 1 . Oxford, etc., Butterworth-Heinemann, 309335.
Walder, J. S. and Fowler, A.. 1994. Channelized subglacial drainage over a deformable bed. J. Glaciol., 40(134), 315.
Wilbur, S. W. 1988. Surging versus non-surging glaciers: a comparison using morphometry andbalance. (M.Sc. thesis, University of Alaska Fairbanks.)
Willis, I. C. 1995. Intra-annual variations in glacier motion: a review. Prog. Phys. Geogr, 19(1), 61106.
Wood, D. M. 1990. Soil behaviour and critical state soil mechanics. Cambridge, Cambridge University Press.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Glaciology
  • ISSN: 0022-1430
  • EISSN: 1727-5652
  • URL: /core/journals/journal-of-glaciology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed