Large submarine sand waves and gravel lag substrates on Georges Bank off Atlantic Canada

By:  and 
Edited by: Peter T Harris and E.K. Baker

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Abstract

Georges Bank is a large, shallow, continental shelf feature offshore of New England and Atlantic Canada. The bank is mantled with a veneer of glacial debris transported during the late Pleistocene from continental areas lying to the north. These sediments were reworked by marine processes during postglacial sea-level transgression and continue to be modified by the modern oceanic regime. The surficial geology of the Canadian portion of the bank is a widespread gravel lag overlain in places by well sorted sand occurring as bedforms. The most widespread bedforms are large, mobile, asymmetrical sand waves up to 19 m in height formed through sediment transport by strong tidal-driven and possibly storm-driven currents. Well-defined curvilinear bedform crests up to 15 km long form a complex bifurcating pattern having an overall southwest–northeast strike, which is normal to the direction of the major axis of the semidiurnal tidal current ellipse. Minor fields of immobile, symmetrical sand waves are situated in bathymetric lows. Rare mobile, asymmetrical barchan dunes are lying on the gravel lag in areas of low sand supply. On Georges Bank, the management of resources and habitats requires an understanding of the distribution of substrate types, their surface dynamics and susceptibility to movement, and their associated fauna.

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Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Large submarine sand waves and gravel lag substrates on Georges Bank off Atlantic Canada
Chapter 15
DOI 10.1016/B978-0-12-385140-6.00015-3
Year Published 2012
Language English
Publisher Elsevier
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 15 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title Seafloor geomorphology as benthic habitat: GeoHab atlas of seafloor geomorphic features and benthic habitats,
First page 261
Last page 275
Country Canada, United States
Other Geospatial Georges Bank
Online Only (Y/N) N
Additional Online Files (Y/N) N