EarthWorks Geospatial Catalog

Curvature: Hueneme Canyon and Vicinity, California, 2007

Author(s)
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Description
This layer is a georeferenced raster image of the curvature map of Hueneme Canyon, California. The curvature raster, in conjunction with bathymetry data, amplitude data, and seismic reflection profiles, was used to interpret geology and geomorphology of Hueneme Canyon. The curvature raster was generated in two steps. First, the source elevation data were combined into a single elevation raster and smoothed using a FocalMean algorithm in ArcGIS 9.3.1, as follows: focalmean([elevation_source], circle, 4, data) This operation smoothes the data by calculating the mean of all cells for which the cell center is within a 4-cell radius of the target cell - essentially calculating a rolling mean of elevation over the entire grid. Second, the curvature of the smoothed source elevation data was calculated using the curvature function in ArcGIS 9.3.1. Curvature is the second derivative of the elevation surface (the slope of the slope) calculated using the methods of Zeverbergen and Thorne (1987). The ArcGIS calculation for total curvature is more accurately described as representing the difference between the cell's value and the average value along the four cardinal directions. Differences between the ArcGIS implementation and the original equations of Zeverbergen and Thorne (1987) are (1) the sign is reversed, and (2) the end value is multiplied by 100. Although curvature was also decomposed into plan and profile curvature to aid in geologic mapping, those products are not shown. This map was published in Scientific Investigations Map 3225 (sheet 11). This layer is part of the USGS Data Series 781.In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage be be used as an interpretation aid for geologic mapping of Hueneme Canyon. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.
Publisher
Geological Survey (U.S.)
Place(s)
California, Ventura County (Calif.), and Pacific Ocean
Subject(s)
Geomorphology, Coasts, Remote sensing, Multibeam mapping, Bathymetric maps, Submarine topography, Seismic reflection method, Imagery and Base Maps, and Oceans
Year
2006-2007
Held by
Stanford
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Use and reproduction
This item is in the public domain. There are no restrictions on use.
Copyright
This work is in the Public Domain, meaning that it is not subject to copyright.
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