Extreme melting at Greenland's largest floating ice tongue

• DOI: 10.5194/tc-18-1333-2024
• Publication Date: 2024-03-22T09:59:59Z
• Authors: Ole Zeising; Niklas Neckel; Nils Dörr; Veit Helm; Daniel Steinhage; Ralph Timmermann; Angelika Humbert
• Keywords: Environmental sciences; Earth sciences; QE1-996.5; info:eu-repo/classification/ddc/550; 550; ddc:550; GE1-350; Geology

Abstract. The 79° North Glacier (Nioghalvfjerdsbrae, 79NG) is one of three remaining glaciers with a floating tongue in Greenland. Although the glacier has been considered exceptionally stable past, earlier studies have shown that ice thinned recent decades. By conducting high-resolution ground-based and airborne radar measurements conjunction satellite remote-sensing observations, we find significant changes geometry 79NG. In vicinity grounding line, 500 m high subglacial channel grown since ∼ 2010 caused surface lowering up to 7.6 a−1. Our results show extreme basal melt rates exceeding 150 a−1 over period 17 d within distance 5 km from where by 32 % 1998. We heterogeneous distribution rates, likely due variability water column thickness channelization base. Time series decrease melting 2018, indicating an inflow colder into cavity below discuss processes led conclude warm ocean currents extensive thinning 79NG's near line last 2 contrast, hypothesize growth increased discharge considerably enlarged area summer warming atmosphere.