The impacts of a subglacial discharge plume on calving, submarine melting and mélange mass loss at Helheim Glacier, south east Greenland

Everett, A, Murray, T, Selmes, N, Holland, DS and Reeve, DE 2021 The impacts of a subglacial discharge plume on calving, submarine melting and mélange mass loss at Helheim Glacier, south east Greenland. Journal of Geophysical Research: Earth Surface. 1-13. https://doi.org/10.1029/2020JF005910 (In Press)

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Abstract/Summary

Almost half of the Greenland ice sheet âĂŹs mass loss occurs through iceberg calving at marine in eterminating glaciers. The presence of buoyant subglacial discharge plumes at the semarineterminiare thought to increase mass loss both through submarine melting and by undercutting that consequently increases calving rates. Plume models are used to predict submarine melting and undercutting. However, there are few observations that allow the serelationships to be tested. Here we use airborne lidar from the terminus of Helheim Glacier,SE23 Greenland to measure the bulge induced at the surface by the upwelling plume. We use these measurements to estimate plume dischargerates using a high-resolution, three-dimensional plume model. Multi-year observations of the plume are compared to are cord of calving from camera and icequake data. We find no evidence to suggest that the presence of a plume, determined by its visibility at the surface, increases the frequency of major calving events and also show that mass loss at the terminus driven directly by plume discharge is significantly less than mass loss from major calving events. The results suggest that the contribution of direct plume driven mass loss at deep marine terminating glaciers may be less than at shallower termini.

Item Type:	Publication - Article
Additional Keywords:	Greenland plume calving glacier lidar melange
Divisions:	Plymouth Marine Laboratory > Science Areas > Earth Observation Science and Applications
Depositing User:	S Hawkins
Date made live:	16 Feb 2021 09:16
Last Modified:	16 Feb 2021 09:16
URI:	https://plymsea.ac.uk/id/eprint/9124

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