Geophysical constraints on the properties of a subglacial lake in northwest Greenland

Abstract. In this study, we report the results of an active-source seismology and ground-penetrating radar survey performed in northwestern Greenland at a site where presence subglacial lake beneath accumulation area has previously been proposed. Both seismic show flat reflector approximately 830–845 m below surface, with reflection coefficient −0.43 ± 0.17, which is consistent acoustic impedance contrast between layer water glacial ice. Additionally, data observe intermittent bottom arriving 14–20 ms after top reflection, corresponding to depth 10–15 m. A strong coda following reflections package sediments although its thickness material properties are uncertain. Finally, use these conduct first-order assessment origins using one-dimensional thermal model hydropotential modeling based on published surface bed topography. Using analyses, narrow origin hypotheses either anomalously high geothermal flux or hypersalinity due local ancient evaporite. Because still unclear, provides intriguing opportunity for first situ sampling Greenland, could better constrain mechanisms formation, evolution, relative importance hydrology.