Authors: Giuseppe Etiope Paolo Favali
Publish Date: 2004/06/18
Volume: 46, Issue: 8, Pages: 987-987
Abstract
Methane CH4 is a greenhouse gas second only in importance to carbon dioxide Nevertheless the present knowledge of its global atmospheric budget is limited by large uncertainties of the source strengths It is commonly assumed that major CH4 sources derive from the biosphere wetlands rice paddies animals termites and that fossil radiocarbonfree CH4 emission is due to and mediated by anthropogenic activity natural gas production and distribution and coal mining However since the beginning of the 2000s several studies have been documenting that significant amounts of “old” CH4 produced within the Earth’s crust are released naturally into the atmosphere through faults and fractured rocks throughout vast areas of hydrocarbonprone sedimentary basins Major geologic emissions of methane GEM are related to mud volcanoes on land and on the seafloor and to submarine gas seepage in pockmark fields As shown by the recent continuous increase of publications
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