Insights on the Surge Behavior of Storstrommen and L. Bistrup Brae, Northeast Greenland, Over the Last Century

We use a multisensor approach to assess the surge history over the past century of Storstrommen and L. Bistrup Brae, which drain the Northeast Ice Stream, Greenland. Storstrommen surged around 1910 and Bistrup in 1913 and during the 1950s. Between 1978 and 1982, the speed of Storstrommen peaked at 3 km/year during an active surge phase that lasted 10 years and the glacier has stayed in a quiescent phase since. Bistrup started to surge in 1988, peaked in 1993, and stopped in 1996. Both glaciers displayed a slow surge initiation and termination. Since 1993, ice builds up in the upper part of Storstrommen at a 1 m/year, its lower part is thinning at its ablation rate of 1.4 m/year, and the grounding line has retreated by 10 km between 1992 and 2017, or 400 m/year. At these current rates, we project that Storstrommen will meet presurge conditions in 2027-2030. Plain Language Summary Storstrommen and L. Bistrup Brae in east Greenland probably are the largest surge-type glaciers in the world. Based on the history of frontal positions, it was suggested a surge periodicity on the order of 70 years. In this study, we use a multisensor approach combining historical data sets with the modern remote sensing techniques to reassess the surge history of Storstrommen and document the unknown behavior of L. Bistrup Brae. We found that, between 1978 and 1982, the speed of Storstrommen peaked at more than 3 km/year during an active surge phase that lasted 10 years and the glacier has stayed in a quiescent phase since. L. Bistrup Brae started to surge in 1988, peaked in 1993, and stopped in 1996. Since 1993, ice builds up in upper part of Storstrommen at a 1 m/year, its lower part is thinning at its ablation rate of 1.4 m/year, and the grounding line has retreated by 10 km between 1992 and 2017. At these current rates of mass accumulation upstream and retreat downstream, we project that Storstrommen will meet presurge conditions in 2027-2030.