Mud volcanoes and ice-keel ploughmarks, Beaufort Sea shelf, Arctic Canada

摘要: The shallow shelf waters of the Beaufort Sea have experienced marine transgression during Holocene (Hill et al. 1985; Taylor 2013). This has led to a warming what was terrestrial permafrost by water incursion, and dissociation subsurface gas hydrates which now vent into waters. Accompanying this change is development conical submarine landforms produced through extrusion sediments, combined with continuing reworking seafloor ploughing action keels drifting ice (Fig. 1). Fig. 1. Multibeam swath bathymetry bathymetric profiles mud volcanoes ice-keel ploughmarks on shelf, Arctic Canada. ( ) Sun-illuminated multibeam-bathymetric image showing ploughmarks. Acquisition system Kongsberg EM302. Frequency 30 kHz. Grid-cell size 5 m. White arrows denote curvilinear ploughmark cross-cutting its previous track. compilation data from CCGS Amundsen -based surveys in 2009 2011. NW–SE narrow, linear artefacts arise instrumentation employed initial survey. Wide, different subsequent b swarm volcanoes. EM3002. 300 …