Sausann Omran, MSc

Kobuk Valley National Park, one of the most remote and pristine wilderness areas in the United States, is experiencing significant environmental changes due to climate-induced permafrost thaw. The Salmon River now shows signs of pollution, including orange-hued waters and a rainbow-like sheen. However, this is not related to any direct anthropogenic causes (i.e. mining or building of infrastructure etc.). These changes can be attributed to the oxidation of pyrite and other sulphide minerals exposed by melting permafrost. This process releases iron and sulphuric acid into the water, leading to increased acidity and the formation of iron-rich precipitates known as "yellow boy”. The oxidation of iron and reduced pH also mobilize trace elements such as arsenic, cadmium, lead, and copper, which pose significant environmental and health risks. Weathered rocks, iron-rich precipitates, and sediments were collected from the surrounding affected streams to investigate these processes. These samples will be examined using a range of techniques, including thin section analysis, inductively coupled plasma mass spectrometry (ICP-MS) and X-ray diffraction (XRD), to determine the speciation and distribution of trace elements and to assess their potential for environmental release.