Flux of methane release and carbon dioxide sequestration at Winterhouse Canyon, Gros Morne, Newfoundland, Canada; a site of continental serpentinization

Abstract

We measured CO2, CH4, and N2O gas fluxes from a pool of ultra-basic water discharging from serpentinized rock in Winterhouse Canyon, Gros Morne, Newfoundland. The flux of CH4 released and CO2 sequestered were calculated to be 4.6 x 10-7 mol/m2min and 1.9 x 10-5 mol/m2min, respectively, while N2O concentrations showed little change. The net radiative forcing due to the changing concentrations of CO2 and CH4 during the sampling period was -0.21, suggesting that the ultra-basic pool in WHC has a net cooling effect on the atmosphere. Similarly, the net global warming potential over a time horizon of 100 years was -7, also suggesting a cooling of the atmosphere. Overall this study was the first to consider the impact of green houses coming into and out of an ultrabasic pool above serpentinized rock and demonstrated the need for more research on the net global impacts of serpentinization. Key words: Serpentinization, Greenhouse Gas, Flux, Chemical Enhancement