Glacier Calving Rates Due to Subglacial Discharge, Fjord Circulation, and Free Convection

• DOI: 10.1029/2017jf004520
• Publication Date: 2018-08-22T18:08:32Z
• Authors: K. M. Schild; C. E. Renshaw; D. I. Benn; A. Luckman; R. L. Hawley; P. How; L. Trusel; F. R. Cottier; A. Pramanik; N. R. J. Hulton
• Keywords: Meltwater; Tidewater; Fjord; Tidewater glacier cycle; Iceberg; Greenland ice sheet; Glacier ice accumulation

Abstract Tidewater glacier calving provides the most direct mechanism of ice transfer from land to ocean. However, physical melt processes influencing remain challenging constrain. In this study we focus on rates at Kongsbreen, a tidewater in Svalbard, due three mechanisms submarine melt: (1) free convection, (2) horizontal fjord circulation, and (3) meltwater discharge. To calculate an overall rate, measure velocity terminus change using Sentinel imagery. We discharge mooring data for mid‐fjord ocean temperature (30–80 m depth), reanalysis results runoff, georectified time‐lapse imagery track icebergs infer surface circulation. Results show that total rate is highly correlated with during 2016 season. When runoff was present, found subglacial accounted order magnitude greater than maximum assigned other two melting combined. Further, Kongsbreen more efficient inducing later season earlier season, implying increase temperatures, timing within and/or development discrete exit channels are critical components rates. As recent atmospheric warming trend subsequent expected continue, it essential understand contributing incorporate these into predictive models.