Ritchie, A.C., and Johnson, S.Y., 2013, Geology and geomorphology--Offshore of Ventura, California:.This is part of the following larger work.
Johnson, Samuel Y. , Dartnell, Peter, Cochrane, Guy R. , Golden, Nadine E. , Phillips, Eleyne L. , Ritchie, Andrew C. , Kvitek, Rikk G. , Greene, H. Gary , Krigsman, Lisa M. , Endris, Charles A. , Seitz, Gordon G. , Gutierrez, Carlos I. , Sliter, Ray W. , Erdey, Mercedes D. , Wong, Florence L. , Yoklavich, Mary M. , Draut, Amy E. , Hart, Patrick E. , and Cochran, Susan A. , 2013, California State Waters Map Series--Offshore of Ventura, California: Scientific Investigations Map SIM 3254, U.S. Geological Survey, Reston, VA.
This is a Vector data set. It contains the following vector data types (SDTS terminology):
The map projection used is WGS 1984 UTM Zone 11N.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.0001
Ordinates (y-coordinates) are specified to the nearest 0.0001
Planar coordinates are specified in Meter
The horizontal datum used is D WGS 1984.
The ellipsoid used is WGS 1984.
The semi-major axis of the ellipsoid used is 6378137.0.
The flattening of the ellipsoid used is 1/298.257223563.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
|Qms||Marine nearshore and shelf deposits|
|Qmsc||Coarse-grained marine nearshore and shelf deposits|
|Qmsf||Fine-grained marine shelf deposits|
|Qmss||Marine shelf scour depressions|
|Qms/Tp||Sediment-covered Pico Formation|
|Qms/Tp?||Sediment-covered Pico Formation, questionable|
text description of map unit
Positive real numbers that are automatically generated.
Positive real numbers that are automatically generated.
This field contains the representation rule in the ArcGIS file geodatabase which applies a solid color fill of a specified CMYK value to each polygon. Representation rules have the same name as the map unit abbreviation.
(831) 460-7814 (voice)
(831) 427-4748 (FAX)
To expand geologic mapping to the seafloor within California's State Waters, to update coastal geologic mapping, and to contribute to a uniform regional geologic database. Additionally, to provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the Santa Barbara coastal plain region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore.
Kvitek, Rikk G. , Dartnell, Peter, Phillips, Eleyne L. , and Cochrane, Guy R. , 2013, Bathymetry--Offshore of Ventura, California: Scientific Investigations Map SIM 3254 (sheets 1, 2), U.S. Geological Survey, Reston, VA.
Dartnell, Peter, Kvitek, Rikk G. , Phillips, Eleyne L. , and Cochrane, Guy R. , 2013, Acoustic backscatter--Offshore of Ventura, California: Scientific Investigations Map SIM 3254 (sheet 3), U.S. Geological Survey, Reston, VA.
Ray W. Sliter, Peter J. Triezenberg, Patrick E. Hart, 2008, High-resolution chirp and mini-sparker seismic-reflection data from the southern California continental shelf--Gaviota to Mugu Canyon: U.S. Geological Survey Open-File Report 2008-1246, U.S. Geological Survey, Reston, VA.
Polygons were primarily mapped by one
of the following methods: (1) interpretation of 2-meter-resolution hillshaded
bathymetry data from bathymetric lidar and sonar surveys (see sheets 1 and 2,
SIM 3254); (2) interpretation of 2-meter-resolution amplitude (backscatter)
data from bathymetric sonar surveys (see sheet 3, SIM 3254); (3) interpretation of 2-meter
interpretation of seismic-reflection-profile data (see sheet 8, SIM 3254).
Map Unit contact locations were interpreted typically at a scale of between 1:1,000 and 1:2,000 using the above base data. Bathymetric sonar and LiDAR data have a horizontal accuracy greater than the resolution of the base data.
Map unit contacts were digitized by heads-up screen digitization of line data on 2-meter-resolution DEMs described above. Horizontal accuracy is estimated to be between 2 and 5 meters depending on how clearly contacts can be resolved.
Most digitized positions on the map are estimated to have better than 5 m horizontal accuracy. There is no elevation data in the database.
Data are complete: no offshore features that could be accurately identified and represented at the compilation scale of 1:24,000 were eliminated or generalized. The smallest area represented is approximately 100 square meters. All geospatial database elements are attributed.
Map elements were visually checked for overshoots, undershoots, duplicate features, polygon closure, and other errors by the lead authors and by the GIS technician(s) who created the digital database. Review drafts of the map were reviewed internally by at least two other geologists for consistency with basic geologic principles and general conformity to USGS mapping standards.
Are there legal restrictions on access or use of the data?
- If physical samples or materials are available, constraints on their on-site access are described in "WR CMG Sample Distribution Policy" at URL: <http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html>
- This information is not intended for navigational purposes.
Read and fully comprehend the metadata prior to data use. Uses of these data should not violate the spatial resolution of the data. Where these data are used in combination with other data of different resolution, the resolution of the combined output will be limited by the lowest resolution of all the data.
Acknowledge the U.S. Geological Survey in products derived from these data. Share data products developed using these data with the U.S. Geological Survey.
This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document these data in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology.