Gridded maps of geological methane emissions and their isotopic signature

Methane (CH4) is a powerful greenhouse gas, whose natural and anthropogenic emissions contribute ∼20 % to global radiative forcing. Its atmospheric budget (sources and sinks), however, has large uncertainties. Inverse modelling, using atmospheric CH4 trends, spatial gradients and isotopic source sig...

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Published in:Earth System Science Data
Main Authors: G. Etiope, G. Ciotoli, S. Schwietzke, M. Schoell
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2019
Subjects:
geo
Online Access:https://doi.org/10.5194/essd-11-1-2019
https://www.earth-syst-sci-data.net/11/1/2019/essd-11-1-2019.pdf
https://doaj.org/article/9925addedef24a9699585b5ee7c28960
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spelling fttriple:oai:gotriple.eu:oai:doaj.org/article:9925addedef24a9699585b5ee7c28960 2023-05-15T15:16:45+02:00 Gridded maps of geological methane emissions and their isotopic signature G. Etiope G. Ciotoli S. Schwietzke M. Schoell 2019-01-01 https://doi.org/10.5194/essd-11-1-2019 https://www.earth-syst-sci-data.net/11/1/2019/essd-11-1-2019.pdf https://doaj.org/article/9925addedef24a9699585b5ee7c28960 en eng Copernicus Publications doi:10.5194/essd-11-1-2019 1866-3508 1866-3516 https://www.earth-syst-sci-data.net/11/1/2019/essd-11-1-2019.pdf https://doaj.org/article/9925addedef24a9699585b5ee7c28960 undefined Earth System Science Data, Vol 11, Pp 1-22 (2019) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2019 fttriple https://doi.org/10.5194/essd-11-1-2019 2023-01-22T17:53:01Z Methane (CH4) is a powerful greenhouse gas, whose natural and anthropogenic emissions contribute ∼20 % to global radiative forcing. Its atmospheric budget (sources and sinks), however, has large uncertainties. Inverse modelling, using atmospheric CH4 trends, spatial gradients and isotopic source signatures, has recently improved the major source estimates and their spatial–temporal variation. Nevertheless, isotopic data lack CH4 source representativeness for many sources, and their isotopic signatures are affected by incomplete knowledge of the spatial distribution of some sources, especially those related to fossil (radiocarbon-free) and microbial gas. This gap is particularly wide for geological CH4 (geo-CH4) seepage, i.e. the natural degassing of hydrocarbons from the Earth's crust. While geological seepage is widely considered a major source of atmospheric CH4, it has been largely neglected in 3-D inverse CH4 budget studies given the lack of detailed a priori gridded emission maps. Here, we report for the first time global gridded maps of geological CH4 sources, including emission and isotopic data. The 1∘×1∘ maps include the four main categories of natural geo-CH4 emission: (a) onshore hydrocarbon macro-seeps, including mud volcanoes, (b) submarine (offshore) seeps, (c) diffuse microseepage and (d) geothermal manifestations. An inventory of point sources and area sources was developed for each category, defining areal distribution (activity), CH4 fluxes (emission factors) and its stable C isotope composition (δ13C-CH4). These parameters were determined considering geological factors that control methane origin and seepage (e.g. petroleum fields, sedimentary basins, high heat flow regions, faults, seismicity). The global geo-source map reveals that the regions with the highest CH4 emissions are all located in the Northern Hemisphere, in North America, in the Caspian region, in Europe and in the East Siberian Arctic Shelf. The globally gridded CH4 emission estimate (37 Tg yr−1 exclusively based on data and ... Article in Journal/Newspaper Arctic Unknown Arctic Earth System Science Data 11 1 1 22
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic geo
envir
spellingShingle geo
envir
G. Etiope
G. Ciotoli
S. Schwietzke
M. Schoell
Gridded maps of geological methane emissions and their isotopic signature
topic_facet geo
envir
description Methane (CH4) is a powerful greenhouse gas, whose natural and anthropogenic emissions contribute ∼20 % to global radiative forcing. Its atmospheric budget (sources and sinks), however, has large uncertainties. Inverse modelling, using atmospheric CH4 trends, spatial gradients and isotopic source signatures, has recently improved the major source estimates and their spatial–temporal variation. Nevertheless, isotopic data lack CH4 source representativeness for many sources, and their isotopic signatures are affected by incomplete knowledge of the spatial distribution of some sources, especially those related to fossil (radiocarbon-free) and microbial gas. This gap is particularly wide for geological CH4 (geo-CH4) seepage, i.e. the natural degassing of hydrocarbons from the Earth's crust. While geological seepage is widely considered a major source of atmospheric CH4, it has been largely neglected in 3-D inverse CH4 budget studies given the lack of detailed a priori gridded emission maps. Here, we report for the first time global gridded maps of geological CH4 sources, including emission and isotopic data. The 1∘×1∘ maps include the four main categories of natural geo-CH4 emission: (a) onshore hydrocarbon macro-seeps, including mud volcanoes, (b) submarine (offshore) seeps, (c) diffuse microseepage and (d) geothermal manifestations. An inventory of point sources and area sources was developed for each category, defining areal distribution (activity), CH4 fluxes (emission factors) and its stable C isotope composition (δ13C-CH4). These parameters were determined considering geological factors that control methane origin and seepage (e.g. petroleum fields, sedimentary basins, high heat flow regions, faults, seismicity). The global geo-source map reveals that the regions with the highest CH4 emissions are all located in the Northern Hemisphere, in North America, in the Caspian region, in Europe and in the East Siberian Arctic Shelf. The globally gridded CH4 emission estimate (37 Tg yr−1 exclusively based on data and ...
format Article in Journal/Newspaper
author G. Etiope
G. Ciotoli
S. Schwietzke
M. Schoell
author_facet G. Etiope
G. Ciotoli
S. Schwietzke
M. Schoell
author_sort G. Etiope
title Gridded maps of geological methane emissions and their isotopic signature
title_short Gridded maps of geological methane emissions and their isotopic signature
title_full Gridded maps of geological methane emissions and their isotopic signature
title_fullStr Gridded maps of geological methane emissions and their isotopic signature
title_full_unstemmed Gridded maps of geological methane emissions and their isotopic signature
title_sort gridded maps of geological methane emissions and their isotopic signature
publisher Copernicus Publications
publishDate 2019
url https://doi.org/10.5194/essd-11-1-2019
https://www.earth-syst-sci-data.net/11/1/2019/essd-11-1-2019.pdf
https://doaj.org/article/9925addedef24a9699585b5ee7c28960
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op_source Earth System Science Data, Vol 11, Pp 1-22 (2019)
op_relation doi:10.5194/essd-11-1-2019
1866-3508
1866-3516
https://www.earth-syst-sci-data.net/11/1/2019/essd-11-1-2019.pdf
https://doaj.org/article/9925addedef24a9699585b5ee7c28960
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container_title Earth System Science Data
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