Enhanced calving rates related to meltwater plume occurrence at Eqip Sermia, Greenland

Glacier calving plays a key role in the recently observed dynamic mass
loss of the Greenland ice sheet. Calving waves, generated by the
sudden detachment of ice from the glacier terminus, can reach tens of
meters of height and have devastating effects upon impact on
surrounding shores. In this study, we describe a new method for the
detection of source location and timing of calving waves, and the
analysis of their magnitude and spreading properties using a
terrestrial radar interferometer (TRI). This method was applied to
11,500 minute-interval TRI acquisitions from Eqip Sermia, Greenland.
More than 2,000 calving waves were detected within seven
days. Quantitative assessment with a Wave Power Index (WPI) showed
spatially distinctive patterns: the sector of the calving front ending
in deep water shows a higher wave activity (+49%) with higher
cumulative WPI (+34%) than the shallow sector. In combination with
a detection of meltwater plume locations, we highlighted a 2.3 times
higher occurrence of visible meltwater plumes in the deep sector than the
shallow one. We found both the cumulated WPI and the number of waves
to increase by more than 80% in the presence of a meltwater plume
in the deep sector while only by 30% in the shallow sector.  We
therefore explain the higher calving activity in the deep sector to be 
strongly related to a combination of higher occurrence of meltwater plumes 
and more efficient calving enhancement linked to better connections 
to deep warm waters.