Geostatistical mapping and spatial variability of surficial sediment types on the Beaufort Sea shelf based on grain size data

摘要: The nearshore Beaufort Sea is a sensitive marine environment that also the focus of oil and gas exploration. Offshore, contains large potential reserves hydrocarbons. Any future exploitation these resources will present unique engineering challenges require an understanding processes govern stability, morphology sediment properties in extensive shallow coastal zone shelf. Knowledge surficial distribution is, therefore, necessary to provide framework for transport, platform foundation conditions balance with environmental concerns, resource development precautionary sustainable management. We describe approach quality controlled mapping grain sizes textures shelf Canadian Arctic. based on size data sampled during period 1969-2008. A replenishment since 1980’s, as well consideration correlating parameters (bathymetry, slope input) cokriging algorithm, amends former way sediments Subsequent processing applying autocorrelation, four single grids (clay, silt, sand gravel) were generated from by ordinary kriging cokriging. Cokriging considered influence texture such bathymetry, slope, cost distance Mackenzie River anisotropy (directional dependency). algorithm expressed variogram was cross-validation predicted standard errors (PSEs). PSE values express maximum deviation modeled real therefore help estimate regions regarding interpolation results each range. type classification scheme applied set clay, gravel content maps resulted map shelf. The PSEs have been compared showed technique provided superior silt slightly improved clay sand. able capture most small variations distribution. Furthermore, reduced nugget effects confirmed grid better indicator when bathymetry slope. For gravel, achieved prediction probabilities was, used generation this class. The use greatly enhanced estimates without additional sampling. Especially regions, like shelf, geostatistical techniques are very useful evaluating seabed because sampling often difficult or impossible due ice even prohibited near platforms. described methodology along inclusion recent data,