Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/6196

Authors: Etiope, G.*
Klusman, R. W.*
Title: Microseepage in drylands: Flux and implications in the global atmospheric source/sink budget of methane
Title of journal: Global and Planetary Change
Series/Report no.: /72 (2010)
Publisher: Elsevier
Issue Date: 2010
DOI: 10.1016/j.gloplacha.2010.01.002
Keywords: microseepage
methane flux
soil sink
drylands
petroleum
greenhouse gas
Abstract: Drylands are considered a net sink for atmospheric methane and a main item of the global inventories of the greenhouse gas budget. It is outlined here, however, that a significant portion of drylands occur over sedimentary basins hosting natural gas and oil reservoirs, where gas migration to the surface takes place, producing positive fluxes of methane into the atmosphere. New field surveys, in different hydrocarbonprone basins, confirm that microseepage, enhanced by faults and fractures in the rocks, overcomes the methanotrophic consumption occurring in dry soil throughout large areas, especially in the winter season. Fluxes of a few units to some tens of mg m−2 day−1 are frequent over oil–gas fields, whose global extent is estimated at 3.5–4.2 million km2; higher fluxes (>50 mg m−2 day−1) are primarily, but not exclusively, found in basins characterized by macro-seeps. Microseepage may however potentially exist over a wider area (∼8 million km2, i.e. 15% of global drylands), including the Total Petroleum Systems, coal measures and portions of sedimentary basins that have experienced thermogenesis. Based on a relatively large and geographically dispersed data-set (563 measurements) from different hydrocarbon-prone basins in USA and Europe, upscaling suggests that global microseepage emission exceeding 10 Tg year−1 is very likely. Microseepage is then only one component of a wider class of geological sources, including mud volcanoes, seeps, geothermal and marine seepage, which cannot be ignored in the atmospheric methane budget.
Appears in Collections:04.04.12. Fluid Geochemistry
Papers Published / Papers in press

Files in This Item:

File SizeFormatVisibility
Article.pdf1.77 MBAdobe PDFonly authorized users View/Open

This item is licensed under a Creative Commons License
Creative Commons


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Share this record
Del.icio.us

Citeulike

Connotea

Facebook

Stumble it!

reddit


 

Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA