Seafloor Relief from Multibeam Bathymetric Sonar, Beaufort Shelf and Slope
The data set includes images of seafloor topography of the Canadian Beaufort Sea, rendered in both grey-scale and colour-shaded false sun-illumination collected by the Geological Survey of Canada (Atlantic and Pacific) through the support of several organizations. The images are derived from soundin...
| Main Authors: | , |
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| Format: | Dataset |
| Language: | English |
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Canadian Cryospheric Information Network
2015
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| Online Access: | https://dx.doi.org/10.5443/12067 https://www.polardata.ca/pdcsearch/?doi_id=12067 |
| Summary: | The data set includes images of seafloor topography of the Canadian Beaufort Sea, rendered in both grey-scale and colour-shaded false sun-illumination collected by the Geological Survey of Canada (Atlantic and Pacific) through the support of several organizations. The images are derived from soundings from a hull-mounted multibeam sonar system. Two research vessels were involved in its collection. The Canadian Coast Guard vessel CCGS Amundsen conducted 3 successive research-oriented field surveys, from 2009 to 2011 using a Knudsen EM302 multibeam instrument. Between September 10th and October 10th, 2013, the Korean Oceanographic Polar Research Institute (KOPRI) research icebreaker Araon surveyed with an EM122 system. The Amundsen data represent an integration of the 3 successive field surveys, data collection was a part of collaboration between oil and gas industry partners (Imperial Oil Resources/British Petroleum), the GSC-A, and ArcticNet. Collaborators from the University of New Brunswick's Ocean Mapping Group have operated the Amundsen's compliment of geophysical equipment for the past several years, extending into the 2011 Expedition. The GSC-A conducted initial and post analysis of the acquired data. The KOPRI dataset stems from collaboration with the GSC-P. Vertical sound speed profiles were obtained from CTD casting stations and these velocities were applied to the acquisition system for correct depth calculations. Geologic features in the image include large and smaller submarine landslides with associated cliffs, faults, translational blocks, retrogressive failure, debrites and evacuation chutes. Sediment cover and areas devoid of cover together with cross-cutting relationships indicate a range in age and process. Other features include mud volcanoes indicating past and recent efflux of mud and fluids to the seabed on the upper slope, iceberg, sea-ice and floating glacier-driven seabed scour, influence by currents and/or past sea-level which limited and locally removed shelf-break glacial and post-glacial muds, incision of shelf-break canyons with differential sediment infill, seabed current-influenced distribution of recent muds derived ultimately from the Mackenzie River, influence on recent distribution of shelf-break muds by the Beaufort Jet, and finally structural disturbance of outermost shelf muds, probably related to degradation of permafrost and fluid migrations, forming mounds, collapses and associated basins. : Purpose: This data was collected to investigate seabed stability in an effort to meet engineering design and regulatory requirements for exploration drilling. Seabed mapping and sediment characterization research is required to investigate seafloor stability conditions in the shelf and slope area of the central Beaufort Sea, with a focus on industry priority mapping blocks. Sediment characteristics and stability, slope stability, seabed features, and ice scouring are also key issues to be examined. The dataset is NOT TO BE USED FOR NAVIGATION! : Summary: These are images of seabed topography derived from shipborne hull-mounted multibeam bathymetric sonar surveys conducted between 2009 and 2013. Expeditions were conducted by ArcticNet and its collaborators and by the Korean Oceanographic Polar Research Institute (KOPRI) and supported by several institutions. The images are rendered with a false shading and/or depth-related colour to resemble illumination from the sun shining from the northeast. This emphasizes the shape of the seabed and details of numerous features. Such images, together with other information about the seabed and shallow sub-seabed provide clues about sediment type, age, and geologic and environmental processes and their change through time. Interpretation by geologists identifies the effects of past glaciers, drifting icebergs, sedimentation originating from the Mackenzie River, cutting of canyons, old and more recent submarine landslides, large-scale disruption of sediments by past (and locally present-day) movement of gas and/or water and ground ice. |
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