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TitleThe behaviour of retreating glaciers controls sediment density flow activity in high-latitude fjords
AuthorNormandeau, A; Dietrich, P; Hughes Clarke, J; Van Wychen, W; Burgess, D; Lajeunesse, P; Ghienne, J -F
SourceISC2018 - 20th International Sedimentological Congress, abstract volume; 2018 p. 1
Year2018
Alt SeriesNatural Resources Canada, Contribution Series 20180227
PublisherIAS
MeetingISC2018 - 20th International Sedimentological Congress; Québec, QC; CA; August 13-17, 2018
DocumentWeb site
Lang.English
Mediapaper
File formatpdf
ProvinceNunavut; Northern offshore region
NTS16; 25H; 25I; 25J; 25N; 25O; 25P; 26; 27; 37E; 37G; 37H; 38A; 38B
AreaBaffin Island
Lat/Long WENS -80.0000 -60.0000 73.0000 61.0000
Subjectshydrogeology; surficial geology/geomorphology; marine geology; sedimentology; environmental geology; fiords; glaciers; ice retreat; sediment transport; coastal environment; sedimentary environment; nearshore environment; hydrodynamics; climate; oceanography; marine environments; deltas; sedimentary structures; drainage systems; hydrologic environment; glacial lakes; ecosystems; ice mass loss; climate change; density flows; drainage basins
ProgramMarine Geohazards, Public Safety Geoscience
Released2018 08 01
AbstractIce mass loss is driving important coastal morphodynamic changes in Arctic regions, from rapid coastal erosion to substantial prograding coastlines. Sediment supply delivered by rivers due to enhanced glacial erosion/ice mass loss has dramatic consequences on nearshore sedimentary environments and associated ecosystems. However, limited data exists in Arctic coasts on the influence of ice mass loss due to climate change in modifying the nearshore hydrodynamic of fjords. Here, we show how the behaviour of retreating glaciers and ice-mass loss influences the generation of density flows in eastern Baffin Island fjords, which has important consequences for bottom water renewal and nutrient and carbon fluxes to the marine environment. Through a detailed analysis of sediment waves formed by sediment density flows on 31 delta fronts mapped from 2003 to 2014 and by extracting their correlative glacio-hydrological drainage basin characteristics, we observed that the presence of glaciers controls the occurrence of density flows. However, lakes formed during glacial retreat, small or large, significantly alter the course of sediment routing to the deltas, leading to the interruption of density flow processes in fjords. Applying these results to 700 glacio-hydrological drainage basins of eastern Baffin Island allows us to predict the location of density flows presently occurring in fjords. These findings inform local communities and stakeholders on the locations where bottom-water renewal and organic carbon and nutrient transfer is more likely to occur, which has significant impacts on ecosystems. Our results greatly improve our understanding of modern density flows and fjord hydrodynamic in high-latitude coasts in response to retreating glacier behaviour in a warming climate.
Summary(Plain Language Summary, not published)
The examination of fjord-delta bathymetry allowed us to identify the factors that control the presence of turbidity currents in fjords. Using these results, we predict where these turbidity currents are active for all of eastern Baffin Island, contributing to seafloor instabilities.
GEOSCAN ID311309