Calving event size measurements and statistics of Eqip Sermia, Greenland, from terrestrial radar interferometry

• Main Authors: Walter, Andrea, Lüthi, Martin P., Vieli, Andreas
• Format: Text
• Language: English
• Published: 2019
• Subjects: Eqip Sermia; Greenland; glacier; Ice Sheet
• Online Access: https://doi.org/10.5194/tc-2019-102; https://www.the-cryosphere-discuss.net/tc-2019-102/

Calving is a crucial process for the recently observed dynamic mass loss changes of the Greenland ice sheet. Despite its importance for global sea level change, major limitations in understanding the calving process remain. This study presents calving event data and statistics recorded with a terrestrial radar interferometer at the front of Eqip Sermia, a marine terminating outlet glacier in Greenland. The data with a spatial resolution of several meters recorded at one-minute intervals was processed to provide source areas and volumes of 1700 individual calving events during a 6 day period. The calving front can be divided into sectors ending in shallow and deep water with different calving statistics and style. For the shallow sector, characterised by an inclined and very high front, calving events are more frequent and larger than for the vertical ice cliff of the deep sector. We suggest that the calving volume missing in our observations of the deep sector is removed by oceanic melt and subaquatic calving, which implies that subaqueous mass loss must be substantial for this sector with a contribution of up to 75 % to the frontal mass loss. The size distribution of the deep sector follows a power law, while the shallow sector is likely represented by a log-normal model. Variations in calving activity and style within the sectors seem to be controlled by the bed topography and the front geometry. Within the short observation period no clear relationship between environmental forcings and calving frequency or event volume could be detected.