Geological Survey of Canada Offshore Single Channel Seismic Reflection Data, Beaufort Shelf and Slope
Ship: CCGS Amundsen CA
Principal Investigator: Steve Blasco
Start Date: 01-01-2009
End Date: 31-03-2015
Citation: Geological Survey of Canada Offshore Single Channel Seismic Reflection Data, Beaufort Shelf and Slope. Unpublished data.
Abstract: High resolution seismic reflection data are collected by deploying acoustic sources (operating in the frequency range centered on 3.5 kHz) to provide a short duration sound pulse that can penetrate the seafloor and sub-seafloor sediments. The sound pulses are reflected by acoustic impedance contrasts back to the receiver of seismic system. An ensemble of sequential echoes forms what is called a seismic section, essentially a two-dimensional time slice or image of acoustic discontinuities in the subsurface. These acoustic images are interpreted by a mapping geologist or geophysicist to infer geological characteristics of the subsurface. Typically these high resolution systems are used to delineate seabed and sub-seabed geological structure down to depths of less than 50m below the seabed. At the Geological Survey of Canada, a variety of high resolution seismic systems are used to map the sub-seabed. Those collected with support from AANDC (Aboriginal Affairs and Northern Development Canada) through the BREA program (Beaufort Regional Environmental Assessment) include only high-frequency swept frequency chirp systems that can resolve sub-metre structure (Knudsen 3.5kHz). These data have been collected in digital formats (generally the SEGY international standard), and are made publically available through various portals including the Polar Data Catalogue, Natural Resources Canada, the University of New Brunswick Ocean Mapping Group and Laval University. The NRCan distribution process is in development and will likely change by April 2015. The supplied url or FTP will likely be little changed; currently it houses only the older (scanned format) profile data on a cruise by cruise basis but this will also include digitally collected data, including the BREA - supported collections. Marine high resolution seismic reflection data are used to address a multitude of issues in the offshore ranging from the recognition and assessment of hazards to offshore development, the assessment of benthic habitat, oil and gas pipeline planning and routing, the understanding of sediment transport processes, to the study of general geological processes, evolution and history.