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06:29
Simulation of Early Earth Hydrothermal Chimneys in a Thermal Gradient Environment
Published on: February 27, 2021
Metabolic stratification driven by surface and subsurface interactions in a terrestrial mud volcano.
Ting-Wen Cheng1, Yung-Hsin Chang, Sen-Lin Tang
1Department of Geosciences, National Taiwan University, Taipei, Taiwan. akira.sch@gmail.com
The ISME Journal
|June 29, 2012
Summary
Terrestrial mud volcanoes emit methane, a greenhouse gas. Microbial processes like methane oxidation and production are active in distinct subsurface niches, influencing methane release and isotopic composition.
Area of Science:
- Geochemistry
- Microbiology
- Geology
Background:
- Terrestrial mud volcanoes (MVs) are geological features that release fluids and hydrocarbons.
- MVs are significant sources of atmospheric methane, a potent greenhouse gas.
- Understanding microbial methane cycling in MVs is crucial for quantifying emissions.
Purpose of the Study:
- To investigate fluid processes, microbial communities, and their functions in a methane-emitting terrestrial mud volcano.
- To link methane-related metabolisms with other microbial and abiotic processes within the mud volcano system.
- To characterize the compartmentalization and activity of microbial metabolisms in relation to geochemical gradients.
Main Methods:
- Geochemical analyses of sediments, gases, and fluids.
- Microbiological and genetic analyses of microbial communities.
- Investigation of fluid mixing dynamics and chemical disequilibria.
Main Results:
- Active aerobic/anaerobic methane oxidation, sulfate reduction, and methanogenesis were identified in stratified microbial niches.
- Surface processes like evaporation and sulfide oxidation contribute to sulfate levels, fueling microbial activity.
- In situ methanogenesis alters thermogenic methane isotopic composition and abundance, potentially exceeding microbial consumption capacity.
Conclusions:
- Metabolic stratification within mud volcanoes is maintained by the mixing of anoxic, methane-rich fluids with oxic, sulfate-rich fluids.
- Microbial methane cycling plays a significant role in regulating methane emissions from terrestrial mud volcanoes.
- Mud volcanoes represent complex geochemical and microbial ecosystems with implications for greenhouse gas dynamics.
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