To estimate methane flux from natural gas bubble streams (seepages) a combined approach was applied, inclusive of detailed echo survey of investigated area and data analysis with the use of specialized software, GIS technique and mathematic simulation. A precise location map of methane seepages in the Dnieper paleo-delta region was obtained. In total 2200 seepages were identified at the investigated area of 378.1 sq.km, which release 16.74 106 m³ at atmospheric pressure (STP), or 12.0 10-3 teragram (Tg) methane a year. Statistical distribution of individual seepage methane flux rates conforms to the lognormal law. We found that 1.9 % of methane from gas bubble streams reaches the atmosphere in gas phase, while 98.1 % dissolves in the water column. Thus,... |