Weak mixing in Lake Kivu: New insights indicate increasing risk of uncontrolled gas eruption

摘要: [1] The deep waters of the East African Rift Lake Kivu contain large amounts dissolved carbon dioxide and methane. The release a fraction these gases, which could be triggered by magma eruption within lake, would have catastrophic consequences for two million people living on its shore. Up to now safety assessment lake was based assumption that gas concentrations in are steady state with residence time 400 years. Turbulent transport regarded as main pathway vertical exchange. Recent measurements analysis processes radically change this evaluation. turbulent exchange is negligible, documented spectacular set several hundred double-diffusive layers. Gases mainly transported out zones slow upwelling 800–1000 Our results indicate methane production sediment has recently increased, leading accumulation consequently decreasing heat input needed trigger devastating release. With estimated current CH4 production, approach saturation century.