Surge of Negribreen, Svalbard

Negribreen, one of the largest glaciers in Svalbard, is currently surging. Negribreen surges only every 100 years approximately, last in the 1930s, and hence there is no modern study on this phenomenon. The current surge provides a unique opportunity for data collection and analysis, aimed at understanding the surge process in an exemplary cold-based tidewater glacier. Glacial acceleration is a major source of uncertainty in sea-level-rise assessment (IPCC 2013), which is typically performed through numerical models, but current dynamic ice-sheet models treat all types of acceleration the same. There are only three types of glacial acceleration and surging is the least understood type, because surges are relatively rare events and thus paucity of existing observations limits our community's ability to analyze this important process.In July 2017, we conducted airborne surveys of Negribreen, collecting high resolution laser altimetry, 2 Hz time-laps imagery, GPS and IMU data and photographs. Negribreen currently moves faster than any other glacier in Svalbard. Ice is discharged rapidly and in increasing volume to the ocean. High-resolution laser altimeter data document surface elevation and spatial characteristics of the crevassed surface, which provide information on the physical processes of rapid flow and deformation. Three-dimensional information on surface changes is derived from a combination of the time-laps imagery and laser altimetry. Results from data analysis, classification and first modeling experiments will be presented at the AGU Fall Meeting.