Observing the fate of methane utilizing Ocean Network Canada's cabled seafloor NEPTUNE Observatory

Abstract

Cabled ocean observatories enable permanent continuous observations in situ in addition to regular sampling during observatory maintenance expeditions, which allow for some of the most comprehensive monitoring to understand the fate of methane all the way from below the seafloor (with instrumented boreholes), through the seafloor (with bottom sensors, cameras or cabled vehicles) into the water column (with sonars). Ocean Networks Canada is operating the NEPTUNE observatory off the coast of Vancouver Island since 2009 with two of its instrument nodes at gas hydrate sites. The first site, Clayoquot Slope, is at around 1200 m water depth and is a site of high fluid expulsion including large amounts of methane gas seepage, which has been observed for over a decade with permanent sonar scanning. The second site, Barkley Canyon, is at about 900 m water depth and has hydrate mounds with exposed gas hydrate on the seafloor, and is unique for its thermogenic methane and also oil seepage, and the most important observations have been made by a remotely-operated cabled and instrumented a seafloor crawler called Wally. This presentation will provide a few highlights on gas hydrate observations and invites the research community for new ideas how to expand the use of the permanent and continuous data flow opportunities that stem from the 24/7 presence of power and communication availability at the two different hydrate sights.