Cryospheric Change as a Driver of Antarctic Seep Emergence 

While the climate sensitivity and significance of subsurface fluid and greenhouse gas reservoirs have received attention in the Arctic, the presence of these features in Antarctica and their contribution to global methane and the carbon cycle remains unknown. Here, we report the discovery of extensive and emergent seafloor seeps, some initiated within the last decade, that are releasing climate-reactive fluids and gases in the coastal Ross Sea. Emission of methane in these shallow waters would expedite transfer to the atmosphere, as reported at other shallow global seep systems. While the origin, driving mechanisms, and environmental consequence of these emerging Antarctic seep systems remains unknown, we postulate that the emergent seepage results from cryospheric cap degradation, which initiates new fluid flow pathways and liberates subsurface fluids and gases. This mechanism is inherently climate sensitive with potential for positive feedback, and may be widespread around the Antarctic Continent, yet the magnitude and scale is currently undetermined.