Permafrost thaw controls iron flux from wetlands and sulfide-bearing rocks to Arctic rivers and streams
Dial RJ , Hanna CT, Sullian PF , Cooper DJ , Tino CJ, Gregory DD, Diamond C, Rieser M , Nicolsky DJ , Hill K , Iwahana G , Koch JC , Carey MP , Miller L, Lyons TW . 2026. Permafrost thaw controls iron flux from wetlands and sulfide-bearing rocks to Arctic rivers and streams. Communications Earth & Environment. (7)
Recent warming has caused widespread iron mobilization into Arctic waterbodies that degrades ecosystems and threatens natural resources. Yet, understanding where and when iron flux occurs remains limited. Here, we investigate iron loading across regional to local scales in Arctic Alaska using climate, water chemistry, and borehole data together with mapped geology and permafrost presence. We show that both anoxic microbial iron reduction and acid rock drainage from iron-sulfide oxidation mobilize iron. Iron influx is strongly associated with lowland wetlands, sulfide-rich upland bedrock, and near-surface permafrost. Acid rock drainage chemistry correlates very strongly with the depth of seasonal thaw above permafrost from the previous year, indicating a one-year lag. These findings clarify the spatial and temporal dynamics of Arctic river rusting, provide a mechanistic understanding of the phenomenon, and may allow anticipation of its occurrence and assessment of its implications for aquatic ecosystem health and subsistence resources under ongoing climate change.
- Type
- Journal Article
- Authors
- Dial, R; Hanna, C; Sullian, P; Cooper, D; Tino, C; Gregory, D; Diamond, C; Rieser, M; Nicolsky, D; Hill, K; Iwahana, G; Koch, J; Carey, M; Miller, L; Lyons, T
- Keywords
- arcn, arctic, climate, iron, permafrost, rivers, rusting, streams
- Subjects
- Ecological Framework: Air and Climate | Weather and Climate | Weather and Climate , Ecological Framework: Geology and Soils | Soil Quality | Soil Function and Dynamics , Ecological Framework: Water | Water Quality | Water Chemistry , Ecological Framework: Landscapes | Extreme Disturbance Events | Extreme Disturbance Events