https://doi.org/10.5194/tc-2019-247 Preprint. Discussion started: 4 November 2019 c Author(s) 2019. CC BY 4.0 License. Quantifying iceberg calving fluxes with underwater noise 5 Oskar Glowacki1,2 and Grant B. Deane1 1Marine Physical Laboratory, Scripps Institution of Oceanography, La Jolla, USA 2Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland Correspondence to: Oskar Glowacki (
[email protected]) 10 Abstract. Accurate estimates of calving fluxes are essential to understand small-scale glacier dynamics and quantify the contribution of marine-terminating glaciers to both eustatic sea level rise and the freshwater budget of polar regions. Here we investigate the application of ambient noise oceanography to measure calving flux using the underwater sounds of iceberg- water impact. A combination of time-lapse photography and passive acoustics is used to determine the relationship between the mass and impact noise of 169 icebergs generated by subaerial calving events from Hans Glacier, Svalbard. The analysis 15 includes three major factors affecting the observed noise: 1. fluctuation of the thermohaline structure, 2. variability of the ocean depth along the waveguide, and 3. reflection of impact noise from the glacier terminus. A correlation of 0.76 is found between the (log-transformed) kinetic energy of the falling iceberg and the corresponding acoustic energy. An error-in- variables linear regression is applied to estimate the coefficients of this relationship. Energy conversion coefficients for non- transformed variables are 8 × 10−7 and 0.92, respectively for the multiplication factor and exponent of the power law. As 20 we demonstrate, this simple model can be used to measure solid ice discharge from Hans Glacier.