|Title||Impacts of four storms in December 2010 on the eastern Shore of Nova Scotia|
|Author||Taylor, R B; Frobel, D; Mercer, D; Fogarty, C; MacAuley, P|
|Source||Geological Survey of Canada, Open File 7356, 2013, 53 pages, https://doi.org/10.4095/292440 (Open Access)|
|Publisher||Natural Resources Canada|
|Area||Halifax; 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|
|Subjects||sedimentology; environmental geology; Nature and Environment; coastal studies; coastal environment; coastal erosion; coastal management; shoreline changes; shorelines; storms; storm deposits; sea level
changes; erosion; tides; beach deposits; environmental impacts|
|Illustrations||location maps; photographs; profiles; tables; aerial photographs; plots|
|Program||Coastal Infrastructure, Climate Change Geoscience|
|Released||2013 04 05|
|Abstract||A 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. |
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.