Glacier Hydrology at Two Svalbard Tidewater Glaciers: An Integrated Remote-Sensing and Field Study

Abstract:

Marine-terminating outlet glaciers discharge most of the Greenland Ice Sheet’s mass loss through iceberg calving, submarine melting, and melt runoff. While calving can be quantified by in situ and remote sensing observations, meltwater runoff, submarine melting, and the subglacial transport of meltwater are not well constrained due to inherent difficulties observing the subglacial and proglacial environments. Previous studies have used sediment plumes and suspended sediment concentration (SSC) as a proxy for glacier meltwater runoff at land terminating glaciers. However, the relationship between satellite reflectance and SSC, established predominantly from land terminating glacier data, does not hold for tidewater glaciers. The number of variables present at a ‘simple’ Greenland tidewater glacier makes it difficult to accurately constrain or identify sediment plume-meltwater discharge relationships, we therefore use tidewater in Svalbard, where systems are simpler and logistics are more straightforward, to establish this association. We use remote sensing and in situ data from two Svalbard tidewater glaciers, Kronebreen and Tunabreen, and establish a well-constrained relationship between satellite band reflectance and SSC in a tidewater glacier setting. We also use sub-glacial pressure gauges, supraglacial GPS units, and measurements of fjord salinity, temperature and turbidity to investigate the relationship between surface melt, sub-glacial water travel, glacier surface velocity and meltwater discharge. Results from the 2015 field season will be presented.