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TitleImpacts of four storms in December 2010 on the eastern Shore of Nova Scotia
DownloadDownloads
AuthorTaylor, R B; Frobel, D; Mercer, D; Fogarty, C; MacAuley, P
SourceGeological Survey of Canada, Open File 7356, 2013, 53 pages, https://doi.org/10.4095/292440
Year2013
PublisherNatural Resources Canada
Documentopen file
Lang.English
Mediaon-line; digital
File formatpdf
ProvinceNova Scotia
NTS11D/10; 11D/11
AreaHalifax; Miseners Long Beach; Cow Bay Beach; Lawrencetown Beach; Conrads Beach; Hartlen Point; Clam Bay Beach
Lat/Long WENS-63.5000 -62.6667 44.8333 44.5000
Subjectssedimentology; environmental geology; coastal studies; coastal environment; coastal erosion; coastal management; shoreline changes; shorelines; storms; storm deposits; sea level changes; erosion; tides; beach deposits; environmental impacts
Illustrationslocation maps; photographs; profiles; tables; aerial photographs; plots
Viewing
Location
 
Natural Resources Canada Library - Ottawa (Earth Sciences)
 
ProgramCoastal Infrastructure, Climate Change Geoscience
Released2013 04 05
AbstractA series of intense low pressure systems struck the Atlantic Maritime Provinces during each week in December 2010. Record storm surges during December 21 and 27 most impacted the shores of Cape Breton Island and southern Gulf of St. Lawrence. Impacts along the coastal highlands of Cape Breton Island were compounded by high river discharge and slope instability caused by heavy rainfall during the December 14 and 21 events.
Detailed observations and repetitive surveys of physical impacts to specific shore types from the December 2010 storms were limited to shores east of Halifax, Nova Scotia. The rapid succession of storms prohibited shoreline recovery and resulted in net shoreline retreat. Cumulative impacts of the storms included: an upper beach and backshore dune retreat of 7 to 9 m along sand and mixedsediment barrier beaches; a beach crest retreat of 2 to 4 m across high and low gravel barriers respectively; and a cliff top erosion of 1 to 1.8 m (between September 2010 and March 6, 2011) which was 4 to 7 times the average annual rate compiled between 1986 and 2009. Despite accelerated shore erosion caused by these storms, longer term evolutionary trends observed at select shores were only slightly altered.
Longshore variations of storm impacts on specific beaches were a function of antecedent shore conditions. (a) At Miseners-Long Beach, representative of a high gravel barrier, increased changes across the upper beach and backshore signal future increased beach mobility, instability and a shift toward a low gravel barrier beach. (b) At Cow Bay Beach, representative of a low gravel barrier, the loss of small segments of high, narrow barrier, and the initiation of a new tidal channel signal continued rapid beach migration into Cow Bay Lake. (c) At Lawrencetown Beach, representative of a mixed sediment barrier, variable changes along the backshore revealed different longer term responses. To the east sediment deposition into backshore craters is depleting shoreface sand reserves and accelerating the breakdown of adjoining foredunes. To the west the movement of large quantities of coarse clasts to the upper beach imply it is evolving toward a high gravel barrier similar to Miseners-Long Beach. (d) At Conrads Beach, representative of a sand barrier, contrasting beach responses were recorded east and west of Fox Point. To the east, a maximum foredune retreat of 9.1 m was caused by repeated wave attack. To the west the foredune was cut back, however the change only represented a temporary interruption in a recent phase of foredune progradation since a tidal inlet was closed in the late 1980s.
Summary(Plain Language Summary, not published)
A series of intense storms struck the Atlantic Maritime Provinces, during each week in December 2010. Record storm surges during December 21 and 27 most impacted the shores of Cape Breton Island and southern Gulf of St Lawrence. Impacts along the coastal highlands of Cape Breton Island were compounded by high river flow and slope instability caused by heavy rainfall. Detailed field observations were limited to shores east of Halifax, Nova Scotia. The rapid succession of storms prohibited shoreline recovery and resulted in net shoreline retreat. Cumulative impacts of all storms included: an upper beach and backshore dune retreat of 7 to 9 m for sand beaches; a beach crest retreat of 2 to 4 m across high and low gravel barriers respectively; and a cliff top erosion of 1 to 1.8 m which was 4 to 7 times the average annual rate compiled between 1986 and 2009. The information collected can be applied to better and management our shorelines for the safety of Canadians.
GEOSCAN ID292440