Mechanisms regulating CO2 and CH4 dynamics in the Azorean volcanic lakes (São Miguel Island, Portugal)
Bio-geochemistry of volcanic lakes in the Azores, Portugal
Accepted: 4 July 2018
HTML: 61
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Authors
Chemical and isotopic vertical profiles from the volcanic lakes of Sete Cidades, Santiago, Fogo, Congro and Furnas (Island of São Miguel, Azores Archipelago, Portugal) were studied to investigate the biogeochemical processes acting at different depths, with a focus on the CO2 and CH4 dynamics. These lakes are fed by meteoric water affected by seawater spray and interacting with volcanic rocks at a relatively low extent. In addition to volcanogenic gas inputs, the biogeochemical processes are influenced by microbial activities since the lakes offer specialized ecological niches for oxic and anoxic metabolism. The lakes were sampled in two extreme conditions of (partial) mixing (winter) and stratification (summer), respectively. The seasonal thermal stratification favored the development of anaerobic hypolimnia, showing relatively high concentrations of NH4+, NO3-, P and other minor species (Fe, Mn, Zn, As) controlled by microbial activity and minerogenetic processes occurring within the lake sediments. The strongly negative d13C-TDIC values measured in almost all the studied lakes suggest dominant contribution of organic carbon. Dissolved gases were mostly consisting of atmospheric compounds with significant concentrations of CO2 and CH4. The d13C-CO2 values were intermediate between those measured in the hydrothermal fluids and those typical of biogenic CO2. Dissolved CH4, which was the most abundant extra-atmospheric gas in the anoxic waters, was measured at significant concentrations even in the aerobic layers, especially in the winter season. This unexpected feature may tentatively be explained by admitting i) convective mixing of shallow and deep waters, and/or ii) aerobic CH4 production. Further investigations, focusing on the recognition of microbial populations able to produce CH4 at different redox conditions, may be useful to corroborate these intriguing hypotheses.
Supporting Agencies
no fundingHow to Cite
-
César Andrade, J. Virgílio Cruz, Fátima Viveiros, Rui CoutinhoEnvironmental Pollution : 2021
-
César Andrade, Fátima Viveiros, J. Virgílio Cruz, Rui CoutinhoJournal of Geochemical Exploration : 2021
-
César Andrade, Fátima Viveiros, J. Virgílio Cruz, Rafael Branco, Lucía Moreno, Catarina Silva, Rui Coutinho, Joana PachecoJournal of Volcanology and Geothermal Research : 2019
-
Danica Mitrović, Ellen C. Hopmans, Nicole J. Bale, Nora Richter, Linda A. Amaral-Zettler, Allix J. Baxter, Francien Peterse, Pedro Miguel Raposeiro, Vítor Gonçalves, Ana Cristina Costa, Stefan SchoutenOrganic Geochemistry : 2023
-
Jonas Stage Sø, Kaj Sand-Jensen, Kenneth Thorø Martinsen, Emma Polauke, Johan Emil Kjær, Kasper Reitzel, Theis KraghScience of The Total Environment : 2023
-
Stefano Fazi, Jacopo Cabassi, Francesco Capecchiacci, Cristiana Callieri, Ester M Eckert, Stefano Amalfitano, Luca Pasquini, Roberto Bertoni, Orlando Vaselli, Franco Tassi, Bertram Boehrer, Giovannella Pecoraino, Lorenza Li Vigni, Sergio Calabrese, Monia Procesi, Michele PaternosterEcohydrology & Hydrobiology : 2024
-
César Andrade, Vittorio Zanon, Fátima Viveiros, J Virgílio Cruz, Adriano Pimentel, Rui CoutinhoBulletin of Volcanology : 2023
-
César Andrade, J. Virgílio Cruz, Fátima Viveiros, Rui CoutinhoJournal of Volcanology and Geothermal Research : 2020
-
João Lopes, Afonso Silva Pinto, Telmo Eleutério, Maria Gabriela Meirelles, Helena Cristina VasconcelosWater : 2022
-
César Andrade, J Virgílio Cruz, Fátima Viveiros, Lúcia Moreno, Letícia Ferreira, Rui CoutinhoApplied Geochemistry : 2024
-
J. Cabassi, F. Capecchiacci, F. Magi, O. Vaselli, F. Tassi, F. Montalvo, I. Esquivel, F. Grassa, A. CapraiJournal of Volcanology and Geothermal Research : 2019
-
Dmitri Rouwet
-
Stefania Venturi, Franco Tassi, Jacopo Cabassi, Antonio Randazzo, Marta Lazzaroni, Francesco Capecchiacci, Barbara Vietina, Orlando VaselliApplied Sciences : 2021