Skip to main content Accessibility help
×
Home

Investigating the ratio of basal drag and driving stress in relation to bedrock topography during a melt season on Storglaciären, Sweden, using force-budget analysis

  • Jim Hedfors (a1), Vincent Peyaud (a1), Veijio A. Pohjola (a1), Peter Jansson (a2) and Rickard Pettersson (a2)...

Abstract

We apply the force-budget technique using the isothermal block-flow model, on Storglaciaren, Sweden, to investigate the ratio between basal drag and driving stress in relation to a bedrock ridge in the bed topography during a peak melt season. The input data consist of glacier surface velocities collected using differential global positioning system surveying of a stake net and geometry from previous radar soundings and digitized ice surface maps. The study focuses on the effects of transverse bedrock ridges upon basal stress conditions. The pattern of the calculated ratio of basal drag and driving stress shows a rhythmical position of relatively high and low basal drags on the stoss and lee sides, respectively, of the bedrock thresholds. One of the zones of low basal drag corresponds to the location where the highest basal sliding rate has been measured previously by borehode deformation studies. This zone also aligns with the area where the drainage system is suggested to change from englacial to subglacial.

  • 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.

      Investigating the ratio of basal drag and driving stress in relation to bedrock topography during a melt season on Storglaciären, Sweden, using force-budget analysis
      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.

      Investigating the ratio of basal drag and driving stress in relation to bedrock topography during a melt season on Storglaciären, Sweden, using force-budget analysis
      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.

      Investigating the ratio of basal drag and driving stress in relation to bedrock topography during a melt season on Storglaciären, Sweden, using force-budget analysis
      Available formats
      ×

Copyright

References

Hide All
Andreasson, P.-G. and Gee, D. 1989. Bedrock geology and morphology of the Tarfala area. Geogr. Ann., 71A(3–4), 235–239.
Björnsson, H. 1981. Radio-echosounding maps of Storglaciaren, Isfallsglaciaren and Rabots glaciar, northern Sweden. Geogr. Ann., 63A(3–4), 225–231.
Eriksson, M., Björnsson, H., Herzfeld, U. C. and Holmlund, P. 1993. Thebottom topography of Storglaciären: a new map based on old and newice depth measurements, analyzed with geostatistical methods. Stockholm, Stockholm University. Department of Physical Geography. (Forskningsrapportserien STOU-NG 95.)
Hedfors, J. R. 2002. Investigations of ice flow in polar regions. (Licentiate thesis, Uppsala University.)
Holmlund, P. 1996. Maps of Storglaciaren and their use in glacier monitoring studies. Geogr. Ann., 78A(2–3), 193–196.
Holmlund, P. and Eriksson, M. 1989. The cold surface layer on Storglaciaren. Geog r. Ann., 71A(3–4), 241–244.
Hooke, R. Le, B. 1981. Flow law for polycrystalline ice in glaciers: comparison of theoretical predictions, laboratory data, and field measurements. Rev. Geophys. Space Phys., 19(4), 664–672.
Hooke, R. Le, B. 1998. Principles of glacier mechanics. Upper Saddle River, NJ, Prentice Hall.
Hooke, R. Le, B., Gould, J. E. and Brzozowski, J. 1983. Near-surface temperatures near and below the equilibrium line on polar and subpolar glaciers. Z. Gletscherkd. Glazialgeol.,19(1),1–25.
Hooke, R. Le, B., Holmlund, P. and Iverson, N. R. 1987. Extrusion flow demonstrated by bore-hole deformation measurements over a riegel, Storglaciaren, Sweden. J. Glaciol.,33(113),72–78.
Hooke, R. Le, B., Calla, P., Holmlund, P., Nilsson, M. and Stroeven, A. 1989. A 3 year record of seasonal variations in surface velocity, Storglaciaren, Sweden. J. Glaciol.,35(120), 235–247.
Hooke, R. Le, B., Pohjola, V.A., Jansson, P. and Kohler, J. 1992. Intra-seasonal changes in deformation profiles revealed by borehole studies, Storglaciaren, Sweden. J. Glaciol.,38(130),348–358.
Høydal, Ø. A. 1996. A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica. J. Glaciol.,42(142), 413–425.
Iverson, N.R., Hanson, B., Le, R. Hooke, B. and Jansson, P. 1995. Flow mechanism of glaciers on soft beds. Science,267(5194),80–81.
Jansson, P. 1995. Water pressure and basal sliding on Storglaciaren, northern Sweden. J. Glaciol.,41(138), 232–240.
Jansson, P. 1996. Dynamics and hydrology of a small polythermal valley glacier. Geogr. Ann., 78A(2–3), 171–180.
Jansson, P. 1997. Longitudinal coupling in ice flow across a subglacial ridge. Ann. Glaciol., 24, 169–174.
Mair, D., Nienow, P., Willis, I. and Sharp, M. 2001. Spatial patterns of glacier motion during a high-velocity event: Haut Glacier d’Arolla, Switzerland. J. Glaciol.,47(156), 9–20.
Mayer, C. and Huybrechts, P. 1999. Ice-dynamic conditions across the grounding zone, Ekstromisen, East Antarctica. J. Glaciol.,45(150),384–393.
Pohjola, V. A. 1993. Ice dynamical studies on Storglaciaren. (Ph.D. thesis, Uppsala University.)
Pohjola, V. A. 1996. Simulation of particle paths and deformation of ice structures along a flow-line on Storglaciaren, Sweden. Geogr. Ann., 78A(2–3), 181–192.
Sandwell, D.T. 1987. Biharmonic spline interpolation of GEOS-3 and SEASAT altimeter data. Geophys. Res. Lett., 2, 139–142.
Van der Veen, C. J. and Whillans, I. M. 1989. Force budget: I. Theory and numerical methods. J. Glaciol.,35(119), 53–60.
Whillans, I. M. and van der Veen, C.J. 1997. The role of lateral drag in the dynamics of Ice Stream B, Antarctica. J. Glaciol.,43(144), 231–237.
Whillans, I. M., Chen, Y. H., vander Veen, C. J. and Hughes, T. J. 1989. Force budget: III. Application to three-dimensional flow of Byrd Glacier, Antarctica. J. Glaciol.,35(119), 68–80.

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