| Title | Distribution and morphology of inner-shelf sand bodies off southwest Newfoundland based on merged multibeam sonar and LiDAR data |
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| Author | Shaw, J; Wu, Y; Potter, D P |
| Source | Canadian Journal of Earth Sciences vol. 57, no. 1, 2019 p. 114-122, https://doi.org/10.1139/cjes-2018-0311 |
| Image |  |
| Year | 2019 |
| Alt Series | Natural Resources Canada, Contribution Series 20180321 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Newfoundland and Labrador; Eastern offshore region |
| NTS | 11I; 11J; 11O; 11P |
| Area | Island of Newfoundland; Cabot Strait; Laurentian Channel; Cape Anguille |
| Lat/Long WENS | -60.0000 -57.0000 48.0000 46.0000 |
| Subjects | marine geology; surficial geology/geomorphology; geophysics; Science and Technology; Nature and Environment; marine sediments; sands; bedforms; morphology; geophysical surveys; acoustic surveys, marine;
side-scan sonar; bathymetry; continental margins; continental shelf; coastal environment; nearshore environment; submarine features; submarine canyons; submarine troughs; sediment transport; oceanography; bottom currents |
| Illustrations | location maps; geoscientific sketch maps; bathymetric profiles |
| Program | Public Safety Geoscience Public Safety Geoscience - Coordination |
| Released | 2019 05 29 |
| Abstract | The inner shelf off southwest Newfoundland, bordering the Laurentian Channel, was mapped with multibeam sonar between depths of 200 m and ~20 m, overlapping with coverage by marine/terrestrial LiDAR
from maximum depths of 30 m to above sea level. The new data provide the first clear view of linkages between terrestrial and nearshore coastal systems and the inner shelf. Offshore sand reservoirs associated with adjacent sandy coastal barriers and
spits are thin (~2 m), and isolated from one another, so that bedrock is the dominant seafloor terrain on the inner most shelf. The offshore sand reservoirs link with complex nearshore bar systems, from which it is inferred that sediment exchange
with terrestrial systems can occur. Several isolated sand bodies are interpreted as residuals from former coastal systems destroyed during the Holocene transgression. The new data reveal the unexpected existence of a submarine canyon that facilitates
transport of sediment from the inner shelf into the deep glacial trough of Laurentian Channel. |
| Summary | (Plain Language Summary, not published)
Combined multibeam sonar and LiDAR off southwest Newfoundland to map the seabed of the white zone - the zone of shallow water that was previously
inaccessible to mapping. It is shown that the seafloor is mostly bedrock, with large sand patches that link with modern beach systems. The survey also revealed a previously unknown submarine canyon draining sand away from local beaches. The paper
is being submitted to the journal TOGETHER with a second paper that applies the same methodology in the Arctic. By comparing the two environments we demonstrate that, because of sea ice and falling sea levels, the shallow seafloor of the Canadian
Arctic Archipelago is very different from that of temperate regions, being characterized by well-preserved glacial terrains. |
| GEOSCAN ID | 313245 |
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