Dataset description: Contours--Offshore Coal Oil Point, California
Geometry
This part of DS 781 presents bathymetric contours for several seafloor maps of Offshore Coal Oil Point, California. The vector data file is included in "Contours_OffshoreCoalOilPoint.zip," which is accessible from https://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. These data accompany the pamphlet and map sheets of Johnson, S.Y., Dartnell, P., Cochrane, G.R., Golden, N.E., Phillips, E.L., Ritchie, A.C., Kvitek, R.G., Dieter, B.E., Conrad, J.E., Lorenson, T.D., Krigsman, L.M., Greene, H.G., Endris, C.A., Seitz, G.G., Finlayson, D.P., Sliter, R.W., Wong, F.L., Erdey, M.D., Gutierrez, C.I., Leifer, I., Yoklavich, M.M., Draut, A.E., Hart, P.E., Hostettler, F.D., Peters, K.E., Kvenvolden, K.A., Rosenbauer, R.J., and Fong, G. (S.Y. Johnson and S.A. Cochran, eds.), 2014, California State Waters Map Series-Offshore of Coal Oil Point, California: U.S. Geological Survey Scientific Investigations Map 3302, pamphlet 57 p., 12 sheets, scale 1:24,000, https://doi.org/10.3133/sim3302.
Contours of the Offshore of Coal Oil Point map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS), by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), and by Fugro Pelagos. Most of the nearshore and shelf regions were mapped by the USGS in the summers of 2006, 2007, and 2008 using a combination of 117 kHz and 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. The far eastern nearshore and shelf regions were mapped by CSUMB in the summer of 2007 using a 244 kHz Reson 8101 multibeam echosounder. The outer shelf and slope regions were mapped by Fugro Pelagos in 2008 using a combination of 400 kHz Reson 7125, 240 kHz Reson 8101, and 100 kHz Reson 8111 multibeam echosounders. The nearshore bathymetry and coastal topography were also mapped by Fugro Pelagos in 2009 for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise using the SHOALS-1000T bathymetric and the Leica ALS60 topographic lidar systems. All of these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical mile limit of California's state waters. A smooth arithmetic mean convolution function applying a weight of 1/9 to each cell in a 3x3 matrix was applied iteratively to the merged bathymetry grid ten times. Following smoothing, contour lines were generated at 10-meter intervals from 10 to 100 m and 50-meter intervals from 100 to 250 m.
