Natural and societal consequences of climate-forced changes of Jostedalsbreen Ice Cap
New measurements of ice thickness on Jostedalsbreen
by Mette Kusk Gillespie, April 26, 2023
After a winter cooped up in front of computers, processing and interpreting previous years radar measurements of ice and snow thickness, we have been looking forward to spring and the opportunity to further improve the data coverage on Jostedalsbreen.
Hence on 27 March in glorious weather, a small group of enthusiastic fieldworkers left for Tunsbergdalsbreen outlet glacier. The aim of the fieldwork was to re-survey the deepest regions of the glacier where the 5 MHz measurements from 2022 failed to detect a bed reflector. We brought the IceRadar system with 2.5 MHz antennas and the 500 MHz Malå snow radar. However, there was less snow compared to when we travelled this route last year, and unfortunately, we were unable to find a safe route for snow scooter travel through the heavily crevassed regions in the lower part of the glacier. After a long day of scouting, digging, pulling, and pushing we decided to postpone the glacier survey for another year with better snow conditions. We managed to measure a little bit in the lowermost region of Tunsbergdalsbreen on the way home, but the long outlay of the 2.5 MHz antennas proved too difficult to manoeuvre around the crevasses that exist in this region. As mentioned, the weather was great, so at least the pictures turned out well!
Pushing and pulling the scooter sledge towards a freshly dug out scooter (photo: Mette Gillespie).
Kåre Øst and Even Loe scouting for a safe route through the crevasses (photo: Mette Gillespie).
Fortunately, we had better luck on 20 April, when we conducted what will likely be the final helicopter measurements on Jostedalsbreen during the JOSTICE project. The fieldwork was made possible through a collaboration with the University in Bergen and Norsk BreMuseum and was funded by UH-nett Vest. In 1972 a small aircraft crashed above Bøyabreen and 49 years later pieces of this aircraft started appearing at the glacier front. With these new helicopter measurements, we want to improve our measurements of ice thickness below the crash site, in order to accurately model the glacier dynamics of Bøyabreen. This will ultimately contribute to an exhibition at Norsk BreMuseum about the aircraft and its journey through the ice.
Sigurd Daniel Nerhus and Torgeir Opeland Røthe working hard to set up the helicopter frame (photo: Mette Gillespie).
Ready to go! The four antenna arms of the 5 MHz system are each fastened along a pole that extends from the wooden frame (photo: Torgeir Opeland Røthe).