Small Volcanic Lakes Tapping Giant Underground Reservoirs

Typography

In its large caldera, Newberry volcano (Oregon, USA) has two small volcanic lakes, one fed by volcanic geothermal fluids (Paulina Lake) and one by gases (East Lake).

In its large caldera, Newberry volcano (Oregon, USA) has two small volcanic lakes, one fed by volcanic geothermal fluids (Paulina Lake) and one by gases (East Lake). These popular fishing grounds are small windows into a large underlying reservoir of hydrothermal fluids, releasing carbon dioxide (CO2) and hydrogen sulfide (H2S) with minor mercury (Hg) and methane into East Lake.

What happens to all that CO2 after it enters the bottom waters of the lake, and how do these volcanic gases influence the lake ecosystem? Some lakes fed by volcanic CO2 have seen catastrophic CO2 degassing during lake overturn (“limnic eruptions”; e.g., Lake Nyos, Cameroon). Could East Lake be a simmering “American lake Nyos”? East Lake went through a short “gas alert” in summer 2020, with strong H2S smells spreading over the caldera region.

Six Wesleyan University undergraduate/graduate students and their advisor set out to measure CO2 fluxes at East Lake each summer between 2015 and 2019.

Read more at: Geological Society of America