Ocean-bottom and surface seismometers reveal continuous glacial tremor and slip

• Published in: Nature Communications
• Main Authors: Podolskiy, Evgeny A., Murai, Yoshio, Kanna, Naoya, Sugiyama, Shin
• Other Authors: MEXT | Japan Society for the Promotion of Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: General Physics and Astronomy; General Biochemistry, Genetics and Molecular Biology; General Chemistry; greenlandic; Tidewater
• Online Access: http://dx.doi.org/10.1038/s41467-021-24142-4; http://www.nature.com/articles/s41467-021-24142-4.pdf; http://www.nature.com/articles/s41467-021-24142-4

Abstract Shearing along subduction zones, laboratory experiments on analogue faults, and sliding along glacier beds are all associated with aseismic and co-seismic slip. In this study, an ocean-bottom seismometer is deployed near the terminus of a Greenlandic tidewater glacier, effectively insulating the signal from the extremely noisy surface seismic wavefield. Continuous, tide-modulated tremor related to ice speed is recorded at the bed of the glacier. When noise interference (for example, due to strong winds) is low, the tremor is also confirmed via analysis of seismic waveforms from surface stations. The signal resembles the tectonic tremor commonly observed during slow-earthquake events in subduction zones. We propose that the glacier sliding velocity can be retrieved from the observed seismic noise. Our approach may open new opportunities for monitoring calving-front processes in one of the most difficult-to-access cryospheric environments.