UNITED STATES OF AMERICA Geological Survey of Canada2 and Fisheries and Oceans4

• Main Authors: Charles Paull, Scott Dallimore, John Hughes-clarke, Steve Blasco, Eve Lundsten, Ussler Iii, Dale Graves, Alana Sherman, Kim Conway, Humfrey Melling, Svein Vagle, Timothy Collett
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: gas hydrate; permafrost; gas venting; thermal warming NOMENCLATURE ROV- Remotely Operated Vehicle PLF- Pingo-Like Features WCAA- Water Col; Arctic; Arctic Ocean; Beaufort Sea
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.684.7995; http://www.mbari.org/arctic_permafrost/Paull+et+al_ICGH.pdf

A cruise was conducted in 2010 to provide ground truth observations of the seafloor along the outer shelf edge and slope of the Beaufort Sea where multibeam mapping in 2009 identified water column acoustic anomalies which were inferred to be gas plumes. Here we report on seafloor observations, gas sampling, pore water chemistry, and preliminary sediment dating from ROV dives and sediment coring conducted during this cruise. These observations confirm that methane is venting from the seafloor at these sites. The location and style of the vents may be attributed to the on-going impact of thermal warming on relict permafrost and gas hydrate on the margin of the Arctic Ocean. We also provide documentation for the existence of gas hydrate occurrences on the Arctic continental slope overlying large fluid expulsion features.