Groundwater investigations at Virkisjokull, Iceland : data report 2012

This report describes field experiments into the groundwater environment around the Virksjőkull glacier in southeast Iceland, which were carried out between September 2011 and September 2012. The report describes these experiments and presents the resulting data: it is not intended to provide any interpretations of the data, but to be a record of project activities and field results. BGS has set up a multidisciplinary observatory at Virkisjökull, which provides an excellent opportunity to characterise and quantify groundwater in the sandur aquifer and its interaction with glacial meltwater. For more information on the wider geoscientific research being carried out at Virkiskjőkull see http://www.bgs.ac.uk/research/glacierMonitoring/home.html. Climate data, including rainfall, and meltwater river flow data are being collected, and considerable datasets are being developed related to glacial mass, glacier movement, and surface topography and geomorphology. The following groundwater-related activities have been carried out and are reported here: • In three short field surveys in September 2011, February 2012 and April 2012, the focus was on: o Collecting samples of shallow (<1m deep) groundwater, meltwater and ice for chemistry, stable isotope and residence time analysis o Testing ground surface permeability on the sandur and the immediate pro-glacial area. • In summer 2012, a longer field campaign focussed on: o Drilling shallow (10-15 m deep) boreholes into the unconsolidated sandur, as three short transects away from the meltwater river, and testing the boreholes to measure aquifer permeability o Drilling two shallow (6-18 m deep) boreholes into volcanic bedrock between the glacier front and the sandur, to help investigate whether groundwater flow through the bedrock plays a significant role in glacier drainage. o Collecting groundwater and additional meltwater samples for chemistry, stable isotope and residence time analysis o Installing sensors to monitor groundwater level, temperature and conductivity throughout the year. o Hand-constructing very shallow (<1m deep) piezometers to extend the borehole transects and to investigate the immediate river-groundwater zone o Further testing of ground surface permeability on the sandur.