Pingos, Permafrost and Pockmarks: linking rapid methane release to landscape dynamics since the Last Glacial Maximum in Svalbard Seminar

Event details

Recent work has shown that continental-scale methane stores formed beneath the former Barents and Scandinavian Ice Sheets (Cremiere et al, 2016; Portnov et al, 2016). Since methane is among the most potent greenhouse gases, its rapid escape to the atmosphere constitutes a significant climate change risk. The retreat of the Barents Ice Sheet is now thought to have initiated this style of release, starting about 12000 years ago and resulting in abundant sea floor features known as pockmarks (Portnov et al, 2016). More recently, we have discovered methane release through coastal springs on land that are connected to the same groundwater aquifer as the pockmarks. These springs are mostly associated with segregated ice features known as pingos, which each discharge > 2 tons of methane a year directly to the atmosphere. They deserve immediate research attention because far less methane removal occurs en-route to the atmosphere than is the case following release into the sea via pockmarks. This seminar will therefore describe how we have sought to better understand the sources, origins and dynamics of groundwater and methane escaping from pingos and other lowland springs in high Arctic Svalbard. I will show how best to locate, sample and interpret data from these features during winter, when the absence of surface meltwaters improves access to the sites and the signal:noise characteristics of the data. Particular emphasis will be given to the role of landscape change since the Last Glacial Maximum, not least because it might explain why methane persists beneath the permafrost today.