Radio-echo soundings of sub-polar glaciers with low-frequency radar

Article English OPEN
Hagen, Jon Ove ; Sætrang, Arne (1991)
  • Publisher: Co-Action Publishing
  • Journal: Polar Research (issn: 1751-8369, eissn: 1751-8369)
  • Related identifiers: doi: 10.3402/polar.v9i1.6782

Air-borne radio-echo soundings of sub-polar glaciers in Svalbard have previously been carried out by Soviet scientists using high frequency radar units of 620 and 440 MHz. Later a British/Norwegian group made soundings with 60 MHz equipment. The high frequency radar units seemed to underestimate the ice thicknesses. The 60 MHz radar unit seemed to give more accurate results when compared to areas with gravity surveyed bed. However, both the Soviet and the British equipment seldom recorded bed-echoes in accumulation areas where firn soaking during summer and thus zero temperatures are likely to occur. A low-frequency impulse radar unit of 8 MHz, however, recorded bed echoes in these areas too. In the accumulation area of Kongsvegen depths down to 440 m were recorded. The glacier bed is thus close to sea level at approximately 12 km from the calving front. Soundings were carried out on Brøggerbreen. Lovenbreen and Kongsvegen. Subglacial maps were generated from the data. Internal reflections that were probably caused by englacial drainage channels could be observed. Frequent internal reflections close to the bed could be interpreted as an indication of temperate ice. However, we could not find any distinct upper level of these reflections.
  • References (16)
    16 references, page 1 of 2

    Bamber, J. L. 1987a: Radioecho sounding studies of Svalbard glaciers. Unpublished Ph.D. thesis, Jesus College. University of Cambridge.

    Bamber, J. L. 1987b: Internal reflecting horizons in Spitsbergen Glaciers. Annals og Glaciology 9, 5-10.

    Bamber, J. L. 1988: Enhanced radar scattering from water inclusions in ice. Journal of Glaciology 34(118). 293-296.

    Bamber, J. L. 1989: Ice/bed interface and englacial properties of Svalbard ice masses deduced from airborne radio-echo sounding data. Journal of Glaciology 35(119), 3C-37.

    Bjbrnsson. H. 1981: Radio-echo sounding maps of Storglaciaren, IsfAlsglaciaren og Rabots glaciar, northern Sweden. Geogr. Ann. 63 A (3-4),225-231.

    Bj~rnsson,H. 1986: Surface and bedrock topography of ice caps in Iceland mapped by radio-echo soundings. Annals of Glaciology 8 , 11-18.

    Dowdeswell, J. A , , Drewry, D. J., LiestQI. 0. & Orheim. 0. 1984a: Airborne radio echo sounding of sub-polar glaciers in Spitsbergen. Norsk Polarinsrirufr, Skrifter nr. 182. 41pp.

    Dowdeswell, J. A,, Drewry, D. J., Liestel, 0. & Orheim, 0. 1984b: Radio-echo sounding of Spitsbergen glaciers: problems in the interpretation of layer and bottom returns. Journal of Glaciology 30(104), 16-21.

    Haeberli, W. & Fisch, W. 1984: Electrical resistivity soundings of glacier beds: a test study on Grubengletscher, Wallis, Swiss Alps. Journal of Glaciology 30(106), 373-376.

    Liestbl, 0.1976: Pingos, springs and permafrost in Spitsbergen. Norsk Polarinstiturr Arbok 1975, 7-29.

  • Metrics
    No metrics available
Share - Bookmark