Small volcanic lakes tapping giant underground reservoirs
|sciencedaily.com 05 Mar 2021 at 14:19|
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.
East Lake accumulates CO2 below its winter ice cover, which is released again in abundance during ice melting and subsequently during the summer months. They also proposed that the East Lake ecosystem is largely driven by its volcanic inputs: CO2, nutrients like phosphorus and trace metals, with the fixed nitrogen nutrient largely provided by local cyanobacteria.
Materials provided by Geological Society of America . Note: Content may be edited for style and length.
Geological Society of America. "Small volcanic lakes tapping giant underground reservoirs." ScienceDaily. ScienceDaily, 5 March 2021.
Geological Society of America. "Small volcanic lakes tapping giant underground reservoirs." ScienceDaily. www.sciencedaily.com/releases/2021/03/210305133716.htm (accessed March 5, 2021).
Feb. 13, 2018 Pleistocene basaltic lavas form a small volcanic field that was erupted from seven vents in the northwestern Lake Tahoe basin. Most of these lavas were erupted above the water and produced lava flows ...
Oct. 16, 2017 Scientists report that small seismic signals in lakes can aid science. As a record of wave motion in a lake, they can reveal when a lake freezes over and when it thaws. And as a small, constant ...
Sep. 7, 2016 As global temperatures rise, how will lake ecosystems respond? As they warm, will lakes -- which make up only 3 percent of the landscape, but bury more carbon than the world s oceans combined -- ...
Aug. 8, 2016 The decrease in fishery productivity in Lake Tanganyika since the 1950s is a consequence of global warming rather than just overfishing, according to a new report. The lake was becoming warmer at the ...