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TitreSeafloor mapping of Frobisher Bay, Baffin Island, Canadian Arctic Archipelago
AuteurTodd, B J; Shaw, J; Campbell, D C; Mate, D J
SourceGEOHAB 2016 - Marine Geological and Biological Habitat Mapping: marine environment mapping and interpretation - from the coast to the deep ocean, abstract booklet; 2016 p. 148
Année2016
Séries alt.Secteur des sciences de la Terre, Contribution externe 20160002
ÉditeurGeoHab
RéunionGEOHAB 2016 - Marine Geological and Biological Habitat Mapping; Winchester; GB; 2-6 mai 2016
Documentlivre
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceRégion extracotière du nord; Nunavut
SNRC25I; 25J/08; 25J/09; 25J/10; 25J/14; 25J/15; 25J/16; 25N/01; 25N/08; 25N/09; 25N/10; 25O/01; 25O/02; 25O/03; 25O/04; 25O/05; 25O/06; 25O/07; 25O/11; 25O/12; 25P
Lat/Long OENS -69.0000 -64.0000 63.7500 62.0000
Sujetsmilieu macrotidal; topographie du fond océanique; topographie du substratum rocheux; caractéristiques sous-marines; dorsales sous-marines; bassins; glissements de terrain; dépôts de glissement de terrain; sédiments marins; dépôts postglaciaires; boues; dépôts glaciaires; elements glaciaires; moraines; moraine, de geer; antecedents glaciaires; glaciation; écoulement glaciaire; déglaciation; retrait de la glace; structures sédimentaires; mégacannelures; gougeage de la glace; sismicité; sédiments glaciomarins; directions d'écoulement glaciaire; glissements translationnels; géologie marine; géologie régional; géologie des dépôts meubles/géomorphologie; géologie de l'environnement; Phanérozoïque; Cénozoïque; Quaternaire; Paléozoïque; Ordovicien
ProgrammeRisques géo marines, Géoscience pour la sécurité publique
Résumé(disponible en anglais seulement)
Frobisher Bay, a macrotidal inlet of the Labrador Sea in southeastern Baffin Island, is 230 km long and varies in width from 40 km at its southeastern extremity to 20 km at its northwest end. It lies within the territory of Nunavut, which has the land area equivalent to Western Europe, but with a population of only ~30,000. Competing industrial uses of ocean space in Frobisher Bay, coupled with concern for habitat protection, has led to the Canada-Nunavut Geoscience Office and the Geological Survey of Canada, in partnership with Memorial University Marine Habitat Mapping Group, ArcticNet and the Government of Nunavut, to undertake a regional seafloor geoscience mapping program to provide the scientific knowledge of geohazards and seabed geology to underpin and manage future development. Because of constraints of climate, vessel availability, and logistics, the mapping coverage is sparse in some areas, but nevertheless provides insights into geological processes.
The inner bay is characterized by narrow, NW-SE trending bedrock ridges with slopes up to 30°, mantled by glaciomarine sediment, with postglacial mud confined to linear basins. Superimposed glacial megaflutes demonstrate ice flow down the bay during the last glacial cycle; arrays of De Geer moraines point to incremental retreat of the grounded margin towards the NW. In shallow coastal areas the seafloor is imprinted by iceberg furrows and pits, mostly relic, with a modern population down to depths of 80 m. The truly distinguishing aspect of the inner bay is the large number of translational submarine slides developed on ridge flanks, typically with steep headwalls, erosional chutes, long runouts, and low-relief depositional lobes with compressional ridges. In contrast, the outer bay has low relief, and the gently-dipping Ordovician bedrock is mantled with glaciomarine sediments, imprinted by iceberg furrows in places.
The presence of numerous translational slides in this Arctic embayment is distinctive and anomalous. Most of the submarine slides preserved on the seabed in the inner part of the bay appear to occur within post-glacial sediments. In Atlantic Canada, mass transport is generally confined to the continental slopes and fjords, with the most intensive activity in the Late Glacial. In Frobisher Bay, seismic activity and macrotidal location might contribute to the abundant seabed instability in the region.
Résumé(Résumé en langage clair et simple, non publié)
La baie Frobisher, un bras de mer macrotidal de la mer du Labrador, dans le sud-est de l'île de Baffin, a une longueur de 230 km de long et sa largeur varie de 40 km à son extrémité sud-est à 20 km à son extrémité nord-ouest. En raison des contraintes climatiques, des conditions de disponibilité des navires et de la logistique, la couverture cartographique de cette région est faible dans certains secteurs, mais elle fournit néanmoins un aperçu des processus géologiques.
GEOSCAN ID297883