Zackenberg River Catchment

In the summer of 2019, Dr Stevenson and Dr Murphy undertook three weeks of fieldwork in the Zackenberg River Catchment to determine the impact of increased physical erosion on carbon dioxide (CO2) removal and release to the atmosphere. The team set out with the aim of measuring a Glacial Lake Outburst Flood (GLOF). Within 24 hours of their arrival at the Zackenberg research station a GLOF stemming from the A. P. Olsen Glacier flowed downstream into the Zackenberg River causing massive river bank erosion, vast sediment deposition and the delivery of up to 90% of the catchment’s annual sediment budget in ~32 hours. Unexpected injury on the expedition prevented sampling from taking place at the foot of the glacier, but the team were able to capture a GLOF event and take other water and sediment samples as planned. The work has so far generated over 500 data points, which are still being analysed. However initial data shows that concentrations of sulfate in the water increased dramatically relative to alkalinity during the GLOF, which was as the team hypothesised. This could be due to the oxidation of sulfide materials, with the resultant sulfuric acid potentially dissolving catbonate materials and releasing CO2 into the atmosphere. Further research and analysis will be required to confirm this. Further data on isotopic measurements taken, and the impact this has on CO2 release into the atmosphere, are due to be analysed and published.