Volcanic carbon cycling in East Lake, Newberry Volcano, Oregon, USA

Abstract The carbon cycle in East Lake (Newberry Volcano, Oregon, USA) is fueled by volcanic CO2 inputs with traces of Hg and H2S. dissolves deep lake waters removed shallow through largely diffusive surface degassing photosynthesis. Escaping gas photosynthate have low δ13C values, leading to δ13C(DIC) (DIC—dissolved inorganic carbon) as high +5.7‰ waters, well above the common global range. A steep depth gradient further established respiration absorption light bottom waters. seasonal starts at >100 t CO2/day after ice melting spring declines ∼40 t/day late summer, ∼11,700 CO2/yr. Thus, volcano monitoring fluxes from crater lakes should consider lacustrine processes that modulate output over time. flux contribution a bubbling “hotspot” increased 20% >90% lake-wide 2015 2019 CE, followed “toxic alert” July 2020. an active “geogenic” ecosystem driven primarily hydrothermal inputs.