Update of annual calving front lines for 47 marine terminating outlet glaciers in Greenland (1999–2018)

• Published in: Geological Survey of Denmark and Greenland Bulletin
• Main Authors: Andersen, Jonas K., Fausto, Robert S., Hansen, Karina, Box, Jason E., Andersen, Signe B., Ahlstrøm, Andreas P., van As, Dirk, Citterio, Michele, Colgan, William, Karlsson, Nanna B., Kjeldsen, Kristian K., Korsgaard, Niels J., Larsen, Signe H., Mankoff, Kenneth D., Pedersen, Allan Ø., Shields, Christopher L., Solgaard, Anne, Vandecrux, Baptiste
• Format: Article in Journal/Newspaper
• Language: English
• Published: Geological Survey of Denmark and Greenland (GEUS) 2019
• Subjects: Greenland; Glacier; Calving front line; Marine terminating glacier; Climate change; Arctic; glacier; Ice Sheet; Iceberg*
• Online Access: https://geusbulletin.org/index.php/geusb/article/view/4296; https://doi.org/10.34194/GEUSB-201943-02-02

The Greenland ice sheet has been losing mass in response to increased surface melting (Khanet al. 2015; van den Broekeet al. 2017) as well as discharge of ice from marine terminating outlet glaciers (van den Broekeet al. 2009; Boxet al. 2018). Marine terminating outlet glaciers flow to the ocean where they lose mass by e.g. iceberg calving. Currently, the mass loss from the Greenland ice sheet is the largest Arctic contributor to global sea-level rise (van den Broekeet al. 2009, 2017; Boxet al. 2018). Therefore, monitoringchanges in the Greenland ice sheet is essential to provide policy makers with reliable data. There is a consensus that mostmarine terminating outlet glaciers have retreated in recent decades, and that the increased calving rates are a response to recent atmospheric and oceanic warming (e.g. Boxet al. 2018; Moonet al. 2018). The rate of dynamic mass loss is determined by changes of the glacier calving front (i.e. its terminus) position, ice thickness and changes in ice flow.Ocean temperature and fjord circulation also influence the calving front stability by melting the glacier below the water line, thinning the ice that is in contact with water (Moonet al. 2014). Change in calving front position is therefore an important indicator for monitoring the dynamic behaviour of the upstream area of the ice sheet, which is further modulated by local topographic features and buttressing effects (Rignot & Kanagaratnam 2006; Nicket al. 2009). The Programme for Monitoring of the Greenland Ice Sheet (PROMICE) is dedicated to monitoring changes in the mass budget of the Greenland ice sheet, including monitoring of the calving front lines ofmarine terminating outlet glaciers. Here, we present an updated collection of annual measurements of end-of-melt-season calving front lines for 47 marine terminating outlet glaciers in Greenland between 1999 and 2018. We also present an example application of the data set, in which we estimate area changes for this group of glaciers since 1999. The Greenland calving front lines were measured from optical satellite imagery obtained from Landsat, Aster, and Sentinel-2 (Table 1). ThePROMICE calving front productis freely available for download as ESRI shapefiles.