Self-sufficient seismic boxes for monitoring glacier seismology

• Main Authors: Nap, Ana, Walter, Fabian, Lüthi, Martin P, Wehrlé, Adrien Justin
• Format: Article in Journal/Newspaper
• Language: English
• Published: McGill University 2023
• Subjects: Institute of Geography; 910 Geography & travel; glacier; Greenland
• Online Access: https://www.zora.uzh.ch/id/eprint/231217/; https://www.zora.uzh.ch/id/eprint/231217/1/ZORA_341.pdf; https://doi.org/10.5167/uzh-231217; https://doi.org/10.26443/seismica.v2i1.245

Glacier seismology is a valuable tool for investigating ice flow dynamics, but sufficient data acquisition in remote and exposed glaciated terrain remains challenging. For data acquisition on a highly crevassed and remote outlet glacier in Greenland we developed self-sufficient and easily deployable seismic stations, "SG-boxes". The SG-boxes contain their own power supply via solar panel, a three-component omni-directional geophone and a GNSS receiver. The SG-boxes can be deployed and retrieved from a hovering helicopter, allowing for deployment in difficult terrain. To assess their performance we conducted a field test comparing the SG-boxes to established on-ice geophone installations at Gornergletscher in Switzerland. Moreover, data from a first SG-box deployment in Greenland were analyzed. The SG-boxes exhibit consistently higher noise levels relative to colocated conventional geophones and a correlation between noise levels, wind and air temperature is found. Despite their noise susceptibility, the SG-boxes detected a total of 13,114 Gornergletscher icequakes over 10 days, which is 30% of the total number of icequakes detected by conventional geophone stations. Hence, even in sub-optimal weather conditions and without additional noise reduction measures, the SG-boxes can provide unique and valuable data from challenging glaciated terrain where no conventional seismic installations are possible.