Attending Goldschmidt 2019 in Barcelona? Consider submitting your abstracts to Session 09c:Biogeochemical Cycling in Changing Glacial Habitats and Downstream Ecosystems. Conveners: Alexander Michaud, Trista Vick-Majors. Description: Glaciers and ice sheets, as major drivers of weathering and erosion, are important features within the critical zone. As the size, distribution, and melt patterns associated with glaciers continue to change, so too will their impacts to downstream ecosystems. Habitats beneath and downstream of glaciers will contend with hydrologic changes leading to altered nutrient and sediment regimes. The microorganisms that catalyze the transformation of elements within glacial habitats and downstream environments will respond to these changes in unknown ways. This session seeks to synthesize knowledge on the impacts of changing hydrology and sediment transport on the biogeochemistry of glaciated systems, the microbial life in those systems, and the downstream consequences of change. We invite abstracts that address biogeochemical linkages within or among components of glaciated systems, or how microbial or biogeochemical processes are affected by changes in glacier movement, hydrology, or extent. Habitats downstream of glaciers are numerous, so we encourage abstracts from studies conducted in fjords, terrestrial glacial forefields, proglacial lakes, supraglacial, and subglacial habitats. The session aims to contextualize how glacial changes will regulate future biogeochemical processes. Abstract submission opens January 15, 2019, and closes March 29, 2019.