Massive Emissions of Carbon During Continental Rifting: Implications for the Carbon Cycle and Climate
Active volcanoes are arguably the main pathways for mantle volatiles, including carbon, to enter the hydrosphere and atmosphere. Carbon return to the mantle via subduction results in a deep carbon cycle that appears balanced within current flux uncertainties. However, recent work (Lee et al., 2016) suggests that carbon degassing through faults in continental rifts, such as the East Africa Rift, contribute a significant and previously unquantified amount of carbon to the atmosphere. If correct, this observation not only implies current net outgassing of carbon from the mantle to the surface it also requires that significant amounts of carbon are stored in the mantle below continents. This talk explores these new aspects of the deep carbon cycle and some of its implications.
Lee, H; Muirhead, J.D.; Fischer, T.P.; Ebinger, C.J.; Kattenhorn, S.A.; Sharp, Z.D.; Kianji, G. (2016) Massive and prolonged deep carbon emissions associated with continental rifting. Nature Geosci. 9, 145–149 doi:10.1038/ngeo2622