HR: 17:45h
AN: NS14A-08    [Abstracts]
TI: Mapping the course of an englacial channel using ground-penetrating radar at Hansbreen, Svalbard
AU: * Murray, T
EM: t.murray@swansea.ac.uk
AF: Swansea University, School of the Environment and Society, Singleton Park, Swansea, SA2 8PP, United Kingdom
AU: Benn, D
AF: University Centre in Svalbard, Department of Geology, Longyearbyen, 9171, Norway
AU: Maghami-Nick, F
AF: Durham University, Department of Geography, South Road, Durham, DH1 3LE, United Kingdom
AU: Adamek, A
AF: University of Silesia, Poland, Faculty of Earth Sciences, 60 Będzińska Str.60, Sosnowiec, 41-200, Poland
AB: A series of surface ground-penetrating radar profiles at 100 MHz have been collected over an englacial channel system 'Crystal Cave' on the tidewater glacier, Hansbreen, Svalbard. The aim of the surveys was assess radar as a method for determining the size and shape of the channel system and its fill, and to map inaccessible parts of the channel system. It is possible to descend into the main channels of the system from moulins along its course and a detailed map of the accessible regions has been made. This mapping allows ground-truthing of the radar interpretation. The channel system consists of multiple channels at different elevations. The channels generally have low gradient sections linked by near vertical shafts. In common with other channels in Svalbard glaciers, the channels probably initiated as a supraglacial features progressively downcutting into the ice and filling with compressed snow from above. We show that ground-penetrating radar can be successfully used to determine the depth, shape, and water content of englacial channels because of the strong contrast in electrical properties between water, ice, and air. This technique has exciting possibilities for the remote monitoring of inaccessible englacial channels. Members of the Polish Station at Hornsund are thanked for their hospitality and logistic support.
DE: 0720 Glaciers
DE: 0776 Glaciology (1621, 1827, 1863)
DE: 0794 Instruments and techniques
SC: Near-Surface Geophysics [NS]
MN: 2007 Fall Meeting