1. Coastal and Marine Hazards and Resources
  2. Geoscience Data System
  3. Dataset 41471

Dataset description: Backscatter [SWATH]--Offshore Santa Cruz, California

This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Santa Cruz map area, California. Backscatter data are provided as a raster file included in "Backscatter_Swath_OffshoreSantaCruz.zip," which is accessible from https://doi.org/10.5066/F7TM785G. These data accompany the pamphlet and map sheets of Cochrane, G.R., Dartnell, P., Johnson, S.Y., Erdey, M.D., Golden, N.E., Greene, H.G., Dieter, B.E., Hartwell, S.R., Ritchie, A.C., Finlayson, D.P., Endris, C.A., Watt, J.T., Davenport, C.W., Sliter, R.W., Maier, K.L., and Krigsman, L.M. (G.R. Cochrane and S.A. Cochran, eds.), 2016, California State Waters Map Series—Offshore of Santa Cruz, California: U.S. Geological Survey Open-File Report 2016-1024, pamphlet 40 p., 10 sheets, scale 1:24,000, https://doi.org/10.3133/ofr20161024. The acoustic-backscatter map of the Offshore of Santa Cruz, California was generated from backscatter data collected by the U.S. Geological Survey (USGS). Mapping was completed in 2009, using a 234-kHz SWATHplus bathymetric sidescan-sonar system. Within the final imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level, the frequency used to image the seafloor, the grazing angle, the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness, and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker
Version1
Keywordssea-floor characteristics, sonar methods, multibeam sonar, sidescan sonar, image mosaics, sea-floor acoustic reflectivity, ecosystems, geology, marine geophysics, bathymetry
Data typesMultibeam, Sidescan
FormatGeoTIFF;
Amount21 MB

Contacts

Contact
Peter Dartnell
Report a problem

Location of materials and files

Public files
Metadatahttps://cmgds.marine.usgs.gov/metadata/pcmsc/SeriesReports/DS_DDS/DS_781/XMLs_on_ScienceBase/F7TM785G_OffshoreSantaCruz/Backscatter_Swath_OffshoreSantaCruz_metadata.xml
Outline - Questions and answers - Text - XML

Activities and equipment

ActivityEquipment
S1009MBSwath
S709MBSwath