Methane oxidation in Lake Kivu (central Africa)1

Abstract

The rate of methane oxidation in Lake Kivu is estimated at 0.48 mmoles m−3 day−1 or 1.16 × 108 m3 yr−1 for the whole lake as measured in a layer of 15 m thickness above the oxic/anoxic interface. A total volume of 50 km3 of methane is calculated to be contained in the lake; the rates of methane production and of methane consumption appear to be of the same order of magnitude. The vertical diffusion of methane, and thereby its oxidation on reaching the oxic surface waters, is strongly restricted by the thermohaline stratification of the lake.