|Title||Sediment bedforms in the Bay of Fundy: a geohazard for tidal power development?|
|Author||Todd, B J; Shaw,
J; Li, M Z; Kostylev, V E; Hayward, S E|
|Source||Geoscience Characterization of the Seabed for Environmental Assessment of Marine Renewable Energy Activities, abstracts volume; 2012 p. 1-2|
|Alt Series||Earth Sciences Sector, Contribution Series 20110425|
|Meeting||Geoscience Characterization of the Seabed for Environmental Assessment of Marine Renewable Energy Activities; Orcas Island, Washington; US; April 30, 2012|
|Province||New Brunswick; Nova Scotia; Eastern offshore region|
|Area||Bay of Fundy|
|Subjects||surficial geology/geomorphology; marine geology; geophysics; Science and Technology; Nature and Environment; Health and Safety; marine sediments; bedforms; tidal scours; energy; tidal power; geophysical
surveys; acoustic surveys, marine; side-scan sonar; bathymetry; seafloor topography; equipment testing; Holocene; glaciomarine sediments; Renewable energy; Phanerozoic; Cenozoic; Quaternary|
|Illustrations||geoscientific sketch maps|
|Abstract||Located on the Atlantic coast of Canada, the Bay of Fundy is a large macrotidal embayment with the World's highest recorded tides and thus the focus of international interest in tidal power development.
High-resolution multibeam sonar imagery of seafloor terrain and backscatter strength, combined with geophysical and sampling data, reveal for the first time the morphology, architecture, and spatial relationships of a spectrum of sediment bedforms.
Flow-transverse bedforms include elongate trains of dunes oriented parallel to the principal current directions, trains of barchan dunes, and dunes occurring as both large fields or in trains that lie transverse to the bay. Larger dunes show evidence
of being 'trapped' as a result of being incised into underlying glaciomarine sediment (Fig. 1). Flow-parallel bedforms are principally multiple straight ridges formerly described as horse mussel reefs but now recognized as bio-bedforms. Banner banks
flank prominent headlands. Bedform assemblages have formed in the lee of major shoals.|
This suite of bedforms developed during the Holocene as tidal energy increased due to the Bay of Fundy approaching resonance. In concert with broad-scale
winnowing (resulting in surface lags throughout the bay), large tidal scours developed in places. In northeastern Bay of Fundy within Minas Passage at the tidal current maxima, one tidal power device has been deployed for testing and retrieved. Three
more devices are scheduled for deployment in 2012 to 2013. Although these prototype devices will be situated on a (rare) exposed bedrock platform, future commercial-scale device arrays will undoubtedly be deployed farther afield in the bay where they
will have to contend with sediment bedforms. The bedforms and their mobility may pose a geohazard for such marine renewable energy development.