Эмиссия метана в гидро- и атмосферу струйными газовыделениями в районе палеодельты р. Днепр в Черном море

Abstract

To estimate the methane flux from natural gas bubble streams (seepages), a combined approach including a detailed echo survey of the investigated area and the data analysis with the use of specialized software, GIS technique, and mathematic simulation is applied. A precise location map of methane seepages in the Dnieper paleodelta region is obtained. In total, 2200 seepages were identified on the investigated area of 387.1 km2. They release 16.74 · 106 m3 at the atmo\-sphe\-ric pressure (STP) or 12.0 · 10–3 teragram of methane a year. The 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 the gas phase, while 98.1% dissolves in the water column. Thus, the most part of methane remains in sea water and enters into the physical, chemical, and biological transformation processes of carbon-containing compounds.