Underwater acoustic signatures of glacier calving

• Published in: Geophysical research letters Vol. 42; no. 3; pp. 804 - 812
• Main Authors: Glowacki, O., Deane, G. B., Moskalik, M., Blondel, Ph, Tegowski, J., Blaszczyk, M.
• Format: Journal Article
• Language: English
• Published: Washington Blackwell Publishing Ltd 16.02.2015; John Wiley & Sons, Inc
• Subjects: Acoustic emission; Acoustics; calving event; Detaching; Geophysics; Glaciers; Ice; Quantitative analysis; Signatures; tidewater glacier; time-lapse photography; Underwater; underwater acoustics; PNE, Norway, Svalbard, Spitsbergen; PNE, Norway, Svalbard, Spitsbergen, Hornsund
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2014GL062859

Climate‐driven ice‐water interactions in the contact zone between marine‐terminating glaciers and the ocean surface show a dynamic and complex nature. Tidewater glaciers lose volume through the poorly understood process of calving. A detailed description of the mechanisms controlling the course of calving is essential for the reliable estimation and prediction of mass loss from glaciers. Here we present the potential of hydroacoustic methods to investigate different modes of ice detachments. High‐frequency underwater ambient noise recordings are combined with synchronized, high‐resolution, time‐lapse photography of the Hans Glacier cliff in Hornsund Fjord, Spitsbergen, to identify three types of calving events: typical subaerial, sliding subaerial, and submarine. A quantitative analysis of the data reveals a robust correlation between ice impact energy and acoustic emission at frequencies below 200 Hz for subaerial calving. We suggest that relatively inexpensive acoustic methods can be successfully used to provide quantitative descriptions of the various calving types. Key Points Underwater sound contains detailed information about different calving modes Poorly understood submarine detachments can be investigated acoustically Energy of impact is strongly correlated with acoustic emission below 200 Hz