Authors: | Berberich, Gabriele M. Ellison, Aaron M. Berberich, Martin B. Grumpe, Arne Becker, Adrian Wöhler, Christian |
Title: | Can a red wood-ant nest be associated with fault-related CH4 micro-seepage? |
Other Titles: | A case study from continuous short-term in-situ sampling |
Language (ISO): | en |
Abstract: | We measured methane (CH4) and stable carbon isotope of methane (δ13C-CH4) concentrations in ambient air and within a red wood-ant (RWA; Formica polyctena) nest in the Neuwied Basin (Germany) using high-resolution in-situ sampling to detect microbial, thermogenic, and abiotic fault-related micro-seepage of CH4. Methane degassing from RWA nests was not synchronized with earth tides, nor was it influenced by micro-earthquake degassing or concomitantly measured RWA activity. Two δ13C-CH4 signatures were identified in nest gas: −69‰ and −37‰. The lower peak was attributed to microbial decomposition of organic matter within the RWA nest, in line with previous observations that RWA nests are hot-spots of microbial CH4. The higher peak has not been reported in previous studies. We attribute this peak to fault-related CH4 emissions moving via fault networks into the RWA nest, which could originate either from thermogenic or abiotic CH4 formation. Sources of these micro-seepages could be Devonian schists, iron-bearing “Klerf Schichten”, or overlapping micro-seepage of magmatic CH4 from the Eifel plume. Given the abundance of RWA nests on the landscape, their role as sources of microbial CH4 and biological indicators for abiotically-derived CH4 should be included in estimation of methane emissions that are contributing to climatic change. |
Subject Headings: | Red wood ants Formica polyctena CH4; δ 13C-CH4 Fault Activity pattern |
URI: | http://hdl.handle.net/2003/38459 http://dx.doi.org/10.17877/DE290R-20378 |
Issue Date: | 2018-03-28 |
Rights link: | http://creativecommons.org/licenses/by/4.0/ |
Appears in Collections: | Arbeitsgebiet Bildsignalverarbeitung |
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File | Description | Size | Format | |
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animals-08-00046.pdf | 75.18 MB | Adobe PDF | View/Open |
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