EGU2020-10204
https://doi.org/10.5194/egusphere-egu2020-10204
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice

Michael Prior-Jones1, Elizabeth Bagshaw1, Jonathan Lees2, Lindsay Clare3, Stephen Burrow3, Jemma Wadham4, Mauro A Werder5, Nanna B Karlsson6, Dorthe Dahl-Jensen7, Poul Christoffersen8, and Bryn Hubbard9
Michael Prior-Jones et al.
  • 1School of Earth and Ocean Sciences, Cardiff University, Cardiff, UK (prior-jonesm@cardiff.ac.uk)
  • 2School of Engineering, Cardiff University, Cardiff, UK
  • 3Department of Aerospace Engineering, University of Bristol, Bristol, UK
  • 4School of Geographical Sciences, University of Bristol, Bristol, UK
  • 5Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zürich, Zürich, Switzerland
  • 6Geological Survey of Denmark and Greenland, Copenhagen, Denmark
  • 7Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
  • 8Scott Polar Research Institute, University of Cambridge, Cambridge, UK
  • 9Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK

Innovative technological solutions are required to access and observe subglacial hydrological systems beneath glaciers and ice sheets. Wireless sensing systems can be used to collect and return data without the risk of losing data from cable breakage, which is a major obstacle when studying fast flowing glaciers and other high-strain environments. However, the performance of wireless sensors in deep and fast-moving ice has yet to be evaluated formally. We report experimental results from Cryoegg: a spherical probe that can be deployed along an ice borehole and either remain fixed in place or potentially travel through the subglacial hydrological system. The probe makes measurements in-situ and sends them back to the surface via a wireless link. Cryoegg uses very high frequency (VHF) radio to transmit data through up to 1.3 km of cold ice to a surface receiving array. It measures temperature, pressure and electrical conductivity, returning all data in real time. This transmission uses Wireless M-Bus on 169 MHz; we present a simple “radio link budget” model for its performance in cold ice and confirm its validity experimentally. Power is supplied by an internal battery with sufficient capacity for two measurements per day for up to a year, although higher reporting rates are available at the expense of battery life. Field trials were conducted in 2019 at two locations in Greenland (the EastGRIP borehole and the RESPONDER project site on Sermeq Kujalleq/Store Glacier) and on the Rhone Glacier in Switzerland.  Our results from the field demonstrate Cryoegg’s utility in studying englacial channels and moulins, including estimating moulin discharge through salt dilution gauging with the instrument deployed deep within the moulin. Future iterations of the radio system will allow Cryoegg to transmit through up to 2.5 km of ice.

How to cite: Prior-Jones, M., Bagshaw, E., Lees, J., Clare, L., Burrow, S., Wadham, J., Werder, M. A., Karlsson, N. B., Dahl-Jensen, D., Christoffersen, P., and Hubbard, B.: Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10204, https://doi.org/10.5194/egusphere-egu2020-10204, 2020

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Presentation version 2 – uploaded on 19 May 2020 , no comments
Updated plot on slide 8 with correct scale.
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