Ray W. Sliter
James E. Conrad
Holly F. Ryan
Peter J. Triezenberg
2017
Chirp seismic-reflection data collected between Oceanside and La Jolla, offshore of southern California, from 2010-06-01 to 2010-06-12 (USGS field activity S-12-10-SC)
chirp seismic-reflection data in SEG-Y format
data release
DOI:10.5066/F7VD6WMM
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.5066/F7VD6WMM
This dataset includes raw and processed, high-resolution seismic-reflection data collected in 2010 to collect information on active offshore faults. The survey is area is offshore southern California between Oceanside and La Jolla. The data were collected aboard the U.S. Geological Survey R/V Parke Snavely. The seismic-reflection data were acquired using an EdgeTech 512 chirp subbottom profiler. Subbottom acoustic penetration spanned tens to about 50 meters, variable by location.
The U.S. Geological Survey (USGS) collected high-resolution seismic-reflection profiles in June 2011, between Oceanside and La Jolla, southern California. The survey was designed to image faults and folds associated with movement on the numerous faults offshore southern California, including the Newport-Inglewood, Coronado Bank, San Diego Trough, and several other unnamed fault zones. This data can be used to update the USGS Quaternary fault database and in shaking hazard models developed by the Working Group for California Earthquake probabilities. This work was funded by the USGS Coastal and Marine Catastrophic Hazards Project. Data were collected aboard the USGS R/V Parke Snavely. Approximately 487 km of single-channel seismic-reflection data were acquired, mainly using a SIG 2mille minisparker [DOI:10.5066/F7QN64W8]. About 434 km of data were collected using an EdgeTech 512 Chirp. Subbottom acoustic penetration spanned tens to about 50 meters, variable by location. This dataset also includes navigation files of the surveyed transects. The images of bedrock, sediment deposits and tectonic structure provide geologic information that is essential to hazard assessment, regional sediment management and coastal and marine spatial planning at Federal, State and local levels, as well as to future research on the geomorphic, sedimentary, tectonic and climatic record of Southern California.
Additional information about the field activity from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=S1210SC
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
20100601
20100612
ground condition at the time the data were collected
As needed
-117.97713
-117.28061
33.28480
32.86867
USGS Metadata Identifier
USGS:8c150cad-e8d9-43bb-a111-a32058e56e9a
Global Change Master Directory (GCMD)
Bathymetry
Continental Margins
ISO 19115 Topic Category
geoscientificInformation
oceans
USGS Thesaurus
sub-bottom profiling
Marine Realms Information Bank (MRIB) keywords
seismic reflection profiling
Data Categories for Marine Planning
Bathymetry and Elevation
None
chirp
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMG
CMGP
Pacific Coastal and Marine Science Center
PCMSC
Geographic Names Information System (GNIS)
Pacific Ocean
State of California
San Diego County
Orange County
Oceanside
La Jolla
None.
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
This information is not intended for navigational purposes.
PCMSC Science Data Coordinator
U.S. Geological Survey, Pacific Coastal and Marine Science Center
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
SEG-Y Rev 1
Identified as best available version.
Subbottom data were collected during USGS cruise S-12-10-SC using an Edgetech 512 Chirp subbottom profiling system consisting of a source transducer and an array of receiving hydrophones housed in a 500-lb “fish” towed at a depth of several meters below the sea surface. Quality control was conducted during the collection process.
Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
Position data were provided by a Differential Global Positioning System (DGPS) navigation receiver. The Edgetech 512 Chirp fish was deployed 7m behind the DGPS receiver. Layback is estimated to be 7 ± 3m. No layback correction from the DGPS receiver position was applied to navigation data.
Depths shown in the seismic data files are in milliseconds (round trip travel time) and are referenced to sea level. Vertical resolution is approximately 0.5 milliseconds and vertical accuracy is approximately ±4 milliseconds depending on sea state.
Process_Description: Seismic-reflection data were collected using an Edgetech 512 Chirp subbottom profiling system consisting of a source transducer and an array of receiving hydrophones housed in a 500-lb “fish” towed at a depth of several meters below the sea surface. The swept-frequency “chirp” source signal is between 500 and 4,500 Hz, and data are recorded by hydrophones located on the bottom of the fish. At boat speeds of 4 to 4.5 nm/hour, seismic traces were collected roughly every 1 to 2 meters. The data consist of three-channels, a raw channel, a 90-degree phase-shifted channel and an “amplitude envelope” channel created and transformed internally from the other two channels. The data were recorded in standard SEG-Y 16-bit integer format with Triton Subbottom Logger (SBL) software that merges seismic-reflection data with differential GPS navigation data.
2010
The processed seismic-reflection SEG-Y files consist of the internally transformed amplitude envelope channel corrected for the depth of the fish below the sea surface using Paradigm Geophysical Echos seismic processing software (see: http://www.pdgm.com/products/echos/).
1) SEG-Y channel with sequence number “1” was written to a SEG-Y file;
2) The fish depth header word was read and converted from millimeters to two-way travel time to create a fish-depth static value; and
3) The fish depth static was applied to the data to correct for the vertical up and down movement of the Chirp fish and a final processed SEG-Y was output.
2010
Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.
20201019
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Data were moved to a new repository, and metadata was edited to reflect the new location. Other edits were performed as needed to bring the metadata up to PCMSC standards, including a slight rewording of the title. No data were changed.
20210831
U.S. Geological Survey
Susan A Cochran
Geologist
Mailing and Physical
2885 Mission Street
Santa Cruz
CA
95060
831-460-7545
scochran@usgs.gov
Horizontal X and Y locations for the seismic profile locations are provided in ASCII position files and are stored in the SEG-Y data trace headers in the standard header locations.
0.00001
0.00001
Decimal degrees
D_WGS_84
WGS_84
6378137.0
298.257223563
Local surface
0.1
meters
Attribute values
Navigation and Seismic Shots with Time Stamp in standard SEG-Y file format
Society of Exploration Geophysicists (SEG) Technical Standards, available for download at http://seg.org/Publications/SEG-Technical-Standards
U.S. Geological Survey - CMGDS
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060
USA
1-831-427-4747
S-12-10-SC.scs.chirp.zip – this zip file contains raw and processed high-resolution seismic-reflection (SEG-Y) and navigation (ASCII) data collected during PCMSC field activity S-12-10-SC. The data are divided up and presented by navigation line, as reflected in the individual file name(s).
Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
SEG-Y
SEG-Y rev 1
Zip file contains the raw and processed seismic data per navigation line
Winzip, 7-zip, or Winrar are free software that will open .zip files
39318
https://doi.org/10.5066/F7VD6WMM
None
20210913
PCMSC Science Data Coordinator
U.S. Geological Survey, Pacific Coastal and Marine Science Center
mailing and physical
2885 Mission St.
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998