Preliminary measurements on methane content in permafrost, Central Yakutia, and some experimental data

The concentration of methane in air bubbles within permafrost was sampled from both alluvial deposits and ice wedges in Eastern Siberia. The values of methane concentration were as high as 6000 ppmv in both frozen soil and ice wedges. The anti-proportional relationship between methane and carbon dioxide concentration values in permafrost was examined. Values of methane concentration in ice wedges are smaller than those in frozen soils. Values of total volumetric air content, water content and density were obtained by on-the-spot investigation. Increases of methane and carbon dioxide concentrations were detected in accordance with increases of water content of frozen soil. Geologically older permafrost contained higher values of methane concentration than younger permafrost. Samples of frozen soils were incubated at temperature -5 degreesC in order to study possible methane production. A slow production in different soils was observed, although the experiments took a long time before measurable changes of methane content could be found. The rate of methane production decreases in time; therefore, long-term forecasts of methane content in frozen soils are still problematical. Copyright (C) 2002 John Wiley Sons, Ltd.