Variability of calving and ice flow during a two-week period using terrestrial radar interferometry

Abstract

Frontal ablation at tidewater outlet glaciers is responsible for a major part of mass loss of the Greenland Ice Sheet. This underscores the need to understand the underlying processes, such as calving and ice flow, with regard to global sea level rise. In this study we explore the temporal and spatial variability of calving activity and ice flow at the major tidewater outlet glacier Eqalorutsit Kangilliit Sermiat (also referred to as Qajuuttap Sermia) in South Greenland and thereby try to get insights into the forcing and relationships between these two processes. This requires high-resolution data which we achieve by using a terrestrial radar interferometer. The instrument provides a temporal resolution of 1 minute and a spatial resolution of a few meters and was running continuously for a two-week field period in August 2023. The data shows considerable spatial and temporal variability of both calving activity and ice flow. Parts of the flow variability can be attributed to a diurnal cycle that is forced by surface melt, whereas enhanced calving activity seems to be tightly linked to locations of major subglacial discharge plumes.