Geochemistry of Jan Mayen subglacial outlet streams, RIS ID 11394

We propose to conduct detailed studies of the hydrochemistry of the outlet stream of Sørbreen, a large, land-terminating outlet on Beerenberg Volcano’s south side. Because of the diurnal nature of glacier surface melt, a 24-hour sampling schedule will allow for assessment of the chemical effects of low and high flow regimes. We will select a sampling site near the glacial terminus where emerging subglacial water has had little opportunity to equilibrate with the atmosphere. Diurnal changes in stream flow will be measured by pressure gauge and by repeated single-vantage photography to assess active channel width. Stream velocity will be measured by timing the speed of floating ice down a path of known distance. pH, water temperature, and electrical conductivity (which correlates to total dissolved solids) will be measured with a submersed probe. Colorimetric alkalinity titrations will be performed in the field. Sediment will be filtered from water samples to prevent further exchange between the suspended sediment and the dissolved fraction. Both filtered papers and waters will be saved for future laboratory analysis. We will also conduct a reconnaissance by boat of several outlets on the northeast side of the volcano, where large sediment plumes of subglacial water are visible in aerial photography. We will collect single samples from land terminating glaciers and, where possible, employ marine samplers to sample sediment plumes of marine terminating glaciers. Data interpretation will focus on three main points. First, the total magnitude of chemical alternation in the subglacial environment of Jan Mayen in the context of other studies of chemical weathering on young volcanic islands. Second, the daily variation at Sørbreen as a tracer of basal hydrology. Lastly, the spatial variation between Jan Mayen glaciers of varying size and proximity to the volcanic cone.