|Title||Backscatter strength and shaded seafloor relief, Lunenburg Bay, Scotian Shelf, offshore Nova Scotia|
|Author||King, E L; Beaver, D|
|Source||Geological Survey of Canada, Open File 8176, 2017, 1 sheet, https://doi.org/10.4095/299687 (Open Access)|
|Publisher||Natural Resources Canada|
|Publisher||Canadian Hydrographic Service|
|Map Info.||geophysical, backscatter strength/seafloor relief, 1:25,000|
|Projection||Universal Transverse Mercator Projection, UTM zone 20T (NAD83)|
|Related||This publication is related to the following
|Province||Eastern offshore region; Nova Scotia|
|Area||Scotian Shelf; Lunenburg Bay|
|Lat/Long WENS|| -64.3333 -64.1250 44.3833 44.2583|
|Subjects||geophysics; marine geology; surficial geology/geomorphology; bathymetry; seafloor topography; bedrock topography; bedforms; megaripples; sand waves; marine sediments; muds; sands; gravels; glaciomarine
deposits; tills; glacial features; drumlins; glacial deposits; grab samples; core samples; grain size analyses; geophysical surveys; magnetic surveys, marine; magnetometer surveys; acoustic surveys, marine; sonar surveys; side-scan sonar;
oceanography; meteorology; modelling; currents; sediment dispersal; erosion; mineral deposits; placer deposits; gold; multibeam bathymetry; waves; hurricanes; Phanerozoic; Cenozoic; Quaternary|
|Illustrations||location maps; index maps; ternary diagrams; models|
|Program||Marine Geohazards, Public Safety
|Released||2017 04 12|
|Summary||(Plain Language Summary, not published)|
This illustrated map depicts acoustic backscatter strength, in shaded relief view, part of a three-map series of Lunenburg Bay at a scale of 1:25 000.
Backscatter is derived from 2004-06 sonar surveys and displayed as a blue (coarse) and beige (finer) colour spectrum. Sample, grainsize and geophysical control is summarized in a map insert as is a summary of the bay's oceanographic conditions.
Although there is no simple relationship between backscatter amplitude and surficial sediment type, together with grainsize, it is the primary guide for mapping seabed sediment type. Bedrock and bedrock with gravel cover is abundant while sand is
common in bedrock crevices. Sand and mud is common the central mid-bay and the more energy-sheltered innermost bay. Tidal currents dominate at the head of the bay but wind, waves and associated currents, paralleling the coastline, are capable of sand
transport, sometimes in small dunes. Coastal erosion contributes to harbour-filling muds, but storms also flush sediment to deeper waters.