Geological Sources of Methane

Abstract

Methane is one of many gases produced by geological processes. Others include: CO2, H2, H2S, N2, SO2, H2O (as steam or water vapour), and the petroleum gases (ethane, propane, butane and pentane). This chapter considers geological sources of methane, and natural pathways which enable it to enter the atmosphere. For the purposes of this chapter `geological' sources are taken to include sediments of all ages: ancient and modern, including those being actively deposited at the present day. Reference is also made to releases associated with geological resource extraction, however the most significant of these (coal and petroleum) are discussed in specific chapters elsewhere in this volume.