UFZ-Seminar "Water and Environment"
Monday, November 18th, 2013, 3pm
Seminarroom, Brückstraße 3a, D-39114 Magdeburg
Alfred Johnny Wüest
Double diffusion and methane in Lake Kivu –
"interfacing" environmental science and engineering
Double-diffusive upward-directed fluxes play a fascinating role in the accumulation of the ~60 km3 of methane dissolved in the 485 m deep and permanently stratified Lake Kivu. Driven by a geothermal flux of ~100 mW m-2 and stratified by salt and carbon-dioxide (from deep subaquatic springs), double-diffusive conditions have evolved: As a result, a spectacular staircase of ~350 sharp interfaces and well-mixed layers have formed probably over centuries or even millennia.
Due to very strong stratification and weak wind forcing, turbulence is negligible and restricted to the convectively-driven double-diffusive layers. As a result, the upward directed fluxes from the subaquatic springs are small for the dissolved constituents: Therefore, not only salt and carbon-dioxide have accumulated in the deep-water but also methane. It has reached harvestable concentrations and is now a resource with a value of ~20 billion dollars.
The links from double-diffusion to methane accumulation and its harvesting is a wonderful example for opportunities in combining environmental science and engineering.
UFZ-intern: If you would like to join from Halle or Leipzig by a video conference, please send an email to firstname.lastname@example.org at the latest by Friday (15.11.) 12pm.
Dr. Christiane Katterfeld
Tel: +49 391 810-9101
Fax: +49 391 810-9111