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TitreHistorical changes in Cow Bay Beach, Halifax County, Nova Scotia
TéléchargerTéléchargements
AuteurTaylor, R B; Frobel, D; Patton, E
SourceCommission géologique du Canada, Dossier public 5902, 2008, 1 feuille, https://doi.org/10.4095/226031 (Accès ouvert)
Image
Année2008
ÉditeurRessources naturelles Canada
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/226031
Mediapapier; numérique; en ligne
Formatspdf; JPEG2000
ProvinceNouvelle-Écosse
SNRC11D/11NW; 11D/11NE
Lat/Long OENS-63.3333 -63.0000 44.7500 44.6667
Sujetsérosion côtière; études côtières; milieu côtièr; littoraux; variations du littoral; tempêtes; etudes des ondes de surface; plages; dépôts cotiers; océanographie; transport des sediments; sables; graviers; géologie de l'environnement; géologie des dépôts meubles/géomorphologie; géologie marine; Nature et environnement
Illustrationslocation maps; photographs; cross-sections
ProgrammeRenforcer la résilience face aux changements climatiques
Diffusé2008 11 06; 2010 06 28
Résumé(disponible en anglais seulement)
From the early 1900s to the 1950s, Cow Bay Beach, also known as Silver Sands Beach, was one of the largest and most popular recreational beaches near Halifax. As many as 5000 people would use the beach on a hot summer Sunday. Recreational facilities included canteens, picnic sites, a merry-go -round and a dance hall. Only minor physical changes in the beach were observed during that period. By 1956, a commercial operation began extracting sediment from the beach for construction of the new airstrip at the nearby Shearwater airbase and for other structures in the Halifax area. Trees were cut down. Power shovels and drag cranes worked along the shore, from west to east, to remove a total of nearly 2 million tons of sediment during the 1950s and 1960s. The resulting collapse of the western beach and expansion of the inlet allowed for the transfer of large volumes of nearshore sediment into Cow Bay Lake. This lasted until at least 1974, when the inlet was nearly closed off again. Sediment excavation was stopped by the courts in 1971. Since the 1950s the 200 metre (m) wide beach with its multiple beach ridges covered by trees has switched to a very low, single beach ridge less than 28 m wide. The seaward edge of the beach has migrated landward from 96 m to just over 200 m in fifty years. ln the process, the foundation of a dancehall, once at the back of the beach, is now seaward of it. After the excavations, the fragile beach began slowly rebuilding until the late1980s. However, it was unable to withstand the impacts of storms during the mid-1990s and so it began migrating rapidly landward. By 2003, waves from Hurricane Juan had cut two channels through the beach, subdividing it into three parts. Since 2005, the landward migration of the central section of beach has accelerated and will continue to do so unless the beach is flattened and submerged below high tide level by storms. If not, it will migrate and build against Moses Island, in Cow Bay Lake. Cow Bay Beach is a striking example of the long-term impacts caused by sand and gravel removal from Nova Scotian beaches, during the post-World War Il construction boom. Beaches are the product of sediment accumulation over 100s and possibly 1000s of years. Sediment supply is therefore limited. Cow Bay Beach is also a reminder of the constant clash between individual property owners rights, and the struggle to protect provincial shorelines for long term public benefits.
GEOSCAN ID226031