Precursor Motion to Iceberg Calving at Jakobshavn Isbræ, Greenland, Observed with Terrestrial Radar Interferometry

• Main Authors: Xie, Surui, Dixon, Timothy H., Voytenko, Denis, Holland, David M., Zheng, Tiantian
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Digital Commons @ University of South Florida 2016
• Subjects: glacier calving; ice block rotation; Lagrangian coordinates; subsurface melting; terrestrial radar interferometry; Earth Sciences; Geology; Greenland; Jakobshavn Isbræ; glacier; Jakobshavn; Jakobshavn isbræ
• Online Access: https://digitalcommons.usf.edu/geo_facpub/1091; https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2091&context=geo_facpub

Time-varying elevations near the calving front of Jakobshavn Isbræ, Greenland were observed with a terrestrial radar interferometer (TRI) in June 2015. An ice block with surface dimensions of 1370 m × 290 m calved on 10 June. TRI-generated time series show that ice elevation near the calving front began to increase 65 h prior to the event, and can be fit with a simple block rotation model. We hypothesize that subsurface melting at the base of the floating terminus breaks the gravity-buoyancy equilibrium, leading to slow subsidence and rotation of the block, and its eventual failure.