Automated detection and analysis of surface calving waves with a terrestrial radar interferometer at the front of Eqip Sermia, Greenland

• Main Authors: Wehrlé, Adrien, Lüthi, Martin P., Walter, Andrea, Jouvet, Guillaume, Vieli, Andreas
• Format: Text
• Language: English
• Published: 2021
• Subjects: Greenland; Eqip Sermia; glacier; Ice Sheet
• Online Access: https://doi.org/10.5194/tc-2021-33; https://tc.copernicus.org/preprints/tc-2021-33/

Glacier calving is a key dynamical process of the Greenland ice sheet and a major driver of its increasing mass loss. Calving waves, generated by the sudden detachment of ice from the glacier terminus, can reach tens of meters of height and provide very valuable insights to quantify calving activity. In this study, we present a new method for the detection of source location, timing and magnitude of calving waves using a terrestrial radar interferometer. This method was applied to 11500 one-minute interval acquisitions from Eqip Sermia, West Greenland, in July 2018. During seven days, more than 2000 calving waves were detected, including waves generated by submarine calving which are difficult to observe with other methods. Quantitative assessment with a Wave Power Index (WPI) yields a higher wave activity (+49 %) and higher temporally cumulated WPI (+34 %) in deep water than under shallow conditions. Subglacial meltwater plumes, occurring 2.3 times more often in the deep sector, increase WPI and the number of waves by a factor 1.8 and 1.3 respectively in the deep and shallow sector. We therefore explain the higher calving activity in the deep sector by a combination of more frequent meltwater plumes and more efficient calving enhancement linked with better connections to warm deep ocean water.