Large-scale experiments into the tsunamigenic potential of different iceberg calving mechanisms

Heller, Valentin; Chen, Fan; Br�hl, Markus; Gabl, Roman; Chen, Xuexue; Wolters, Guido; Fuchs, Helge

Abstract

Mass balance analysis of ice sheets is a key component to understand the effects of global warming. A significant component of ice sheet and shelf mass balance is iceberg calving, which can generate large tsunamis endangering human beings and coastal infrastructure. Such iceberg-tsunamis have reached amplitudes of 50 m and destroyed harbours. Calving icebergs interact with the surrounding water through different mechanisms and we investigate five; A: capsizing, B: gravity-dominated fall, C: buoyancy-dominated fall, D: gravity-dominated overturning and E: buoyancy-dominated overturning. Gravity-dominated icebergs essentially fall into the water body whereas buoyancy-dominated icebergs rise to the water surface. We find with unique large-scale laboratory experiments that iceberg-tsunami heights from gravity-dominated mechanisms (B and D) are roughly an order of magnitude larger than from A, C and E. A theoretical model for released iceberg energy supports this finding and the measured wave periods upscaled to Greenlandic outlet glaciers agree with field observations. Whilst existing empirical equations for landslide-tsunamis establish estimates of an upper envelope of the maximum iceberg-tsunami heights, they fail to capture the physics of most iceberg-tsunami mechanisms.

Citation

Heller, V., Chen, F., Brühl, M., Gabl, R., Chen, X., Wolters, G., & Fuchs, H. (2019). Large-scale experiments into the tsunamigenic potential of different iceberg calving mechanisms. Scientific Reports, 9(1), Article 861. https://doi.org/10.1038/s41598-018-36634-3

• Journal Article Type: Article
• Acceptance Date: Nov 25, 2018
• Online Publication Date: Jan 29, 2019
• Publication Date: Jan 29, 2019
• Deposit Date: Jan 30, 2019
• Publicly Available Date: Jan 30, 2019
• Journal: Scientific Reports
• Print ISSN: 2045-2322
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 1
• Article Number: 861
• DOI: https://doi.org/10.1038/s41598-018-36634-3
• Keywords: Multidisciplinary
• Public URL: https://nottingham-repository.worktribe.com/output/1506210
• Publisher URL: https://www.nature.com/articles/s41598-018-36634-3