Title | Filling in the 'white strip': onshore-offshore geomorphological mapping on the Scotian Shelf |
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Author | Todd, B J ;
Parsons, S A |
Source | Annual Conference, GEOHAB 2019, Marine Geological and Biological Habitat Mapping, abstracts; 2019 p. 194 |
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Year | 2019 |
Alt Series | Natural Resources Canada, Contribution Series 20190075 |
Publisher | VSEGEI Press (St. Petersburg, Russia) |
Meeting | Annual Conference, GEOHAB 2019, Marine Geological and Biological Habitat Mapping; Saint Petersburg; RU; May 13-17, 2019 |
Document | book |
Lang. | English |
Media | digital; on-line |
File format | pdf |
Province | Eastern offshore region; Nova Scotia |
NTS | 10; 11; 20; 21 |
Area | Atlantic Ocean; Scotian Shelf |
Lat/Long WENS | -69.0000 -55.0000 48.0000 39.5000 |
Subjects | marine geology; surficial geology/geomorphology; environmental geology; geophysics; Science and Technology; Nature and Environment; continental margins; continental shelf; marine environments; littoral
environment; marine sediments; glacial landforms; drumlins; drumlinoids; moraines; seafloor topography; bathymetry; remote sensing; satellite imagery; geophysical surveys; acoustic surveys, marine; glacial history; ice margins; Laurentide Ice Sheet;
Marine biology; Habitats; Protected areas; Management; Digital elevation data; glaciomarine sediments; Phanerozoic; Cenozoic; Quaternary |
Program | Offshore Geoscience |
Released | 2019 05 01 |
Abstract | The littoral zone of marine habitats, or the so-called 'white strip' often appearing on bathymetric and habitat maps, is a recurring technical challenge for seafloor mapping. The white strip is
frequently, depending on the tidal cycle, too shallow and dangerous for surface survey vessel operations and too energetic for the deployment of valuable and delicate autonomous underwater vehicles. Concurrently, the littoral zone is often the locus
of the most challenging aspects of marine spatial management with competing interests which include recreation, fishing, renewable energy installations, pipelines, seafloor cables, and Marine Protected Areas (MPAs). The littoral zone off Nova Scotia,
on the Scotian Shelf, is host to lucrative fishing grounds and is presently being considered by the Canadian government for MPA designation. Habitat maps are required to underpin informed decision-making so that all sectors can abide by the marine
spatial planning decision in this region. Subaerial geomorphological mapping is based on the revision of published surficial geology field mapping, with further insight gained using the Advanced Spaceborne Thermal Emission and Reflection
Radiometer (ASTER), Shuttle Radar Topography Mission (SRTM) 1-arc second (30 m) global digital elevation models, and commercially collected terrestrial CHS (Canadian Hydrographic Service) LiDAR. The region is dominated by drumlin fields interpreted
as originating from southward flowing ice during the Last Glacial Period (LGP). Seafloor geomorphological mapping is based on a 100 m bathymetric grid released in 2018 by the CHS, single beam sonar soundings provided by Olex AS, and marine LiDAR
collected commercially for the CHS. Although glacial landforms in the littoral zone were modified by erosion during sea level rise since the end of the LGP, the orientation of drumlinoid features and recessional moraines are interpreted as marking
the northward retreat of the Laurentide Ice Sheet margin across the Scotian Shelf. The resulting onshore-off shore geomorphological map will inform subsequent sediment sampling, seabed imagery collection, and sediment transport modelling which, in
turn, will strengthen the marine spatial planning decision for the white strip off Nova Scotia. |
Summary | (Plain Language Summary, not published) The littoral zone of marine habitats, or the so-called 'white strip' often appearing on bathymetric and habitat maps, is a perennial technical challenge
for seafloor mapping. Habitat maps are required to underpin informed decision-making so that all sectors can abide by the marine spatial planning decision. New technologies are being applied to this mapping challenge off Nova Scotia. The resulting
onshore-offshore geomorphological map will inform subsequent sediment sampling, seabed imagery, and sediment transport modelling. The results of the modelling will underpin the marine spatial planning decision for the white strip off Nova
Scotia. |
GEOSCAN ID | 314709 |
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