Start Date/Time: Friday, August 14, 2009, 1:30 PM
Location: Hardisty Conference Center
Speaker:Alfred Johny Wueest Eawag (Swiss Federal Institute of Aquatic Sciences and Technology), Switzerland
Title: Lake Kivu: Fascination of double diffusion and the large methane resource
The 485 m deep Lake Kivu (Rwanda, DR Congo) is among the most fascinating lakes on earth. Not only does it host a spectacular staircase of more than 300 interface-layers, it also contains ~60 km3 methane and ~300 km3 carbon dioxide and is permanently density-stratified by salty, carbon dioxide-rich water released by sub-aquatic springs. Those springs and their chemical composition affect the lake stratification: Especially, lake-internal nutrient upwelling, algae growths and the subsequent methane production in the deep waters depend on the quantity and quality of the spring discharges. Over the centuries, methane has accumulated to an amount, which can be economically exploited, but which also poses a risk (limnic eruption like in Nyos) to the riparian ~2 million people. To avoid building-up of such a risk of gas eruption, the two governments have decided to use the methane, worth more than $20 billions.