GEOSCAN Search Results: Fastlink


TitleMulti-decadal coastal evolution of a north Atlantic shelf-edge vegetated sand island - Sable Island, Canada
AuthorEamer, J B RORCID logo; Didier, D; Kehler, D; Manning, I; Colville, D; Manson, G; Jagot, A; Kostylev, V E
SourceLandscape and seascape responses to Canada's changing climate; Canadian Journal of Earth Sciences 2021 p. 1-14, Open Access logo Open Access
Alt SeriesNatural Resources Canada, Contribution Series 20200520
PublisherCanadian Science Publishing
Mediapaper; digital; on-line
File formatpdf; html
ProvinceEastern offshore region; Nova Scotia
NTS10; 11
AreaSable Island
Lat/Long WENS -60.2500 -59.5000 44.0833 43.8333
Subjectsmarine geology; surficial geology/geomorphology; environmental geology; geophysics; Nature and Environment; Science and Technology; continental margins; continental shelf; coastal environment; shoreline changes; offshore islands; barrier islands; sands; dunes; climate effects; sea level changes; vegetation; remote sensing; photogrammetric surveys; airphoto interpretation; modelling; sediment transport; coastal erosion; oceanography; geological evolution; Sable Island Bank; Climate change; marine beach sediments; Wind; Trends
Illustrationslocation maps; geoscientific sketch maps; profiles; photographs; tables; aerial photographs; plots
ProgramClimate Change Geoscience Coastal Infrastructure
Released2021 05 28
AbstractImpacts from a changing climate, in particular sea-level rise, will be most acutely felt on small oceanic islands. A common configuration of mid-latitude islands is the sandy barrier island. Sable Island, Nova Scotia, Canada is a vegetated sand island near the shelf edge, 160 km from the nearest point of land, that is morphologically similar to a barrier island. This study uses 60 years of airphoto records to analyse changes in coastline position through digitized shore and vegetation (foredune proxy) lines. Rates of coastal movement are analysed to model the future (2039) coastal configuration. The analyses suggest that the majority of the coastline on Sable Island is in retreat, with net retreat on the south side of the island only partially offset by modest net advance on the north side. The different morphologies of the beach-dune systems of South Beach and North Beach, driven by incident wind and waves, yield these different coastline responses. Projected loss of 10 ha by 2039 of the climax heath vegetative community to shoreline retreat suggests a trend toward island instability due to coastline migration. Island-wide data set trends show support for two different but complementary hypotheses about whole-island evolution: (1) the island is mobile via bank migration driving southern coastline changes and experiencing sediment transport toward the east, or (2) the island is generally immobile and losing subaerial sediments (and thus shrinking) likely due to ongoing (and accelerating) sea-level rise.
Summary(Plain Language Summary, not published)
Sable Island is a small island composed almost entirely of sand located ~160 km from mainland Nova Scotia, Canada. Only a few tens of metres in elevation at its highest point and at most 1.5 km wide at its widest, the island is particularly susceptible to sea-level rise and increased storminess. We used historical airphotos and modern digital imagery to look at how the shoreline evolved over the last ~60 years. We found that, in general, shorelines are retreating, particularly on the south-facing shoreline. Impacts on infrastructure are expected to occur within the next 20 years, and the stable heath vegetation community (and to a lesser extent the rare freshwater ponds) will experience irreversible losses. The island as a whole may be either migrating northeastward or is more or less immobile and eroding.

Date modified: