Digital optical televiewing of ice boreholes

• Main Authors: Hubbard, Bryn, Roberson, Sam, Samyn, Denis, Merton-Lyn, Derek
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: Géologie et minéralogie; Journal of Glaciology
• Online Access: http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/167477; https://dipot.ulb.ac.be/dspace/bitstream/2013/167477/3/doi_151107.pdf

Digital optical televiewing, recently developed to log and map terrestrial boreholes, provides a complete orientated image of borehole walls at a resolution of 1 mm along hole and typically <1 mm around hole. Here we provide an overview of optical televiewer (OPTV) technology and operation, and outline the potential contributions of the technique to ice-mass research with reference to an OPTV log of a borehole ∼21 m deep drilled in the lower accumulation area of Glacier de Tsanfleuron, Switzerland. The OPTV image of this borehole successfully reveals a variety of visibly contrasting ice types. These ice types have been characterized and their orientation mapped and, on the basis of this information, interpreted as: (1) primary foliation; (2) summer/autumn erosion surfaces; and (3) incipient foliation. Importantly, unrolled OPTV images can be inverted to recreate a virtual image of the borehole core, potentially, for the first time, allowing ice cores to be orientated. SCOPUS: ar.j info:eu-repo/semantics/published