Tidal sedimentology and geomorphology in the central Salish Sea straits, British Columbia and Washington State

Simple item page
dc.contributor.authorMullan, Sean
dc.contributor.supervisorBarrie, James Vaughn
dc.contributor.supervisorPospelova, Vera
dc.date.accessioned2018-01-03T20:02:10Z
dc.date.copyright2017en_US
dc.date.issued2018-01-03
dc.degree.departmentSchool of Earth and Ocean Sciencesen_US
dc.degree.levelDoctor of Philosophy Ph.D.en_US
dc.description.abstractIntra-archipelago waterways, including tidal strait networks, present a complex set of barriers to, and conduits for sediment transport between marine basins. Tidal straits may also be the least well understood tide-dominated sedimentary environment. To address these issues, currents, sediment transport pathways, and seabed sedimentology & geomorphology were studied in the central Salish Sea (Gulf and San Juan Islands region) of British Columbia, Canada and Washington State, USA. A variety of data types were integrated: 3D & 2D tidal models, multibeam bathymetry & backscatter, seabed video, grab samples, cores and seismic reflection. This dissertation included the first regional sediment transport modelling study of the central Salish Sea. Lagrangian particle dispersal simulations were driven by 2D tidal hydrodynamics (~59-days). It was found that flood-tide dominance through narrow intra-archipelago connecting straits resulted in the transfer of sediment into the inland Strait of Georgia, an apparent sediment sink. The formative/maintenance processes at a variety of seabed landforms, including a banner bank with giant dunes, were explained with modelled tides and sediment transport. Deglacial history and modern lateral sedimentological and morphological transitions were also considered. Based on this modern environment, adjustments to the tidal strait facies model were identified. In addition, erosion and deposition patterns across the banner bank (dune complex) were monitored with 8-repeat multibeam sonar surveys (~10 years). With these data, spatially variable bathymetric change detection techniques were explored: A) a cell-by-cell probabilistic depth uncertainty-based threshold (t-test); and B) coherent clusters of change pixels identified with the local Moran's Ii spatial autocorrelation statistic. Uncertainty about volumetric change is a considerable challenge in seabed change research, compared to terrestrial studies. Consideration of volumetric change confidence intervals tempers interpretations and communicates metadata. Techniques A & B may both be used to restrict volumetric change calculations in area, to exclude low relative bathymetric change signal areas.en_US
dc.description.embargo2018-12-07
dc.description.scholarlevelGraduateen_US
dc.identifier.urihttp://hdl.handle.net/1828/8943
dc.languageEnglisheng
dc.language.isoenen_US
dc.rightsAvailable to the World Wide Weben_US
dc.subjecttidal strait networksen_US
dc.subjectsediment transport pathwaysen_US
dc.subjectseabed sedimentologyen_US
dc.subjectmarine geomorphologyen_US
dc.subjectSalish Seaen_US
dc.subjectGulf Islandsen_US
dc.subjectSan Juan Islandsen_US
dc.subjectmultibeam bathymetryen_US
dc.subjectLagrangian particle dispersalen_US
dc.subjecttidal hydrodynamicsen_US
dc.subjectStrait of Georgiaen_US
dc.subjectStrait of Juan de Fucaen_US
dc.subjectbanner banken_US
dc.subjectgiant dunesen_US
dc.subjecttidal strait facies modelen_US
dc.subjectbathymetric change detectionen_US
dc.subjectt-testen_US
dc.subjectlocal Moran's Iien_US
dc.subjectdepth uncertaintyen_US
dc.subjectvolumetric change confidence intervalsen_US
dc.subjectdeglacial historyen_US
dc.subjectrepeat surveysen_US
dc.subjectsand dynamicsen_US
dc.subjecttidesen_US
dc.subjectsonaren_US
dc.subjectmarine renewable energyen_US
dc.subjectoffshore pipelines and cablesen_US
dc.subjectbenthic habitaten_US
dc.subjectspatial autocorrelationen_US
dc.subjectspatial analysis and statisticsen_US
dc.subjectgeographic information system (GIS)en_US
dc.subjectfinite element method (FEM)en_US
dc.titleTidal sedimentology and geomorphology in the central Salish Sea straits, British Columbia and Washington Stateen_US
dc.typeThesisen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Sean_Mullan_PhD_2017.pdf
Size:
14.71 MB
Format:
Adobe Portable Document Format
Description:
PhD dissertation
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Electronic Theses and Dissertations (ETD)
Theses (Earth and Ocean Sciences)
 
University of Victoria Libraries

We acknowledge and respect the Lək̓ʷəŋən (Songhees and Esquimalt) Peoples on whose territory the university stands, and the Lək̓ʷəŋən and W̱SÁNEĆ Peoples whose historical relationships with the land continue to this day.