None
Dataset (offsite)
2011-09-12
creation
Minisparker seismic-reflection data of field activity B-05-11-CC, from Point Sur to Morro Bay, offshore central California, 2011-09-12 to 2011-09-26
This data release includes marine geophysical data collected on cruise B-05-11-CC between Point Sur and Morro Bay, California. The overall goal of this research is to understand the shallow geologic framework of this area as a contribution to the California Seafloor Mapping Program (Johnson and others, 2017). Particular focus is on mapping active faults and documenting the distribution and thickness of offshore, unconsolidated sediment.
Approximately 700 km of single-channel, seismic-reflection data between Point Sur and Morro Bay were collected during the cruise. Seismic profiles were collected at 1 km line spacing between Point Sur and Piedras Blancas, crossing the Hosgri-San Gregorio fault system 60 times. Data were also collected to the south on the south flank of Piedras Blancas (south of San Simeon) crossing the Hosgri-San Gregorio fault 13 times at 800 m line spacing. Farther south, additional data were collected offshore of Morro Bay with a focus on crossing the Los Osos fault zone. Data collected in the southern two areas overlap with and supplement data available in Sliter and others (2009).
Seismic-reflection data were collected using a minisparker system that creates an acoustic signal by discharging an electrical pulse between electrodes and a ground that generates a frequency spectrum roughly between 200 and 1600 Hz. At boat speeds of 4 to 4.5 nm/hour, seismic traces were collected roughly every 1 to 2 meters. Water depths were between 20 m and 600 m. Acoustic pulses were generated at 0.5-second intervals on profiles where maximum depth was about 300 m; a 1-second interval was used on the deeper water profiles. Standard SEG-Y files were generated using a Triton Subbottom Logger (SBL). Seismic data processing was accomplished using Sioseis, a public-domain software developed at Scripps Institute of Oceanography (part of the University of California at San Diego), and SeismicUnix developed at the Colorado School of Mines. The processing of these data consisted of a bandpass filter, mute function, automatic gain control, water bottom detect, swell correction, and scaling/plotting. Both raw data in SEG-Y format and processed (corrected) data are provided here.
Suggested Citation: Johnson, S.Y., Hartwell, S.R., Sliter, R.W., and Beeson, J.W., 2017, Minisparker seismic-reflection data of field activity B-05-11-CC, from Point Sur to Morro Bay, offshore central California, 2011-09-12 to 2011-09-26: U.S. Geological Survey data release, doi:10.5066/F7K35S44
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
compilation
Seismic:Active:SCS
Seismic:Reflection
Other
DigitalSeg:DigitallyAcquired
DigitalSeg
Online
Unspecified
fieldSession
Seismic-reflection data were collected using a minisparker system that creates an acoustic signal by discharging a 500-Joule, high-voltage electrical pulse between electrodes and a ground that generates a frequency spectrum roughly between 200 and 1,600 Hz. At boat speeds of 4 to 4.5 nm/hour, seismic traces were collected roughly every 1 to 2 meters. The data were recorded on a 15-m-long hydrophone streamer in standard SEG-Y 32-bit floating-point format with Triton Subbottom Logger (SBL) software that merges seismic-reflection data with differential GPS navigation data.
2011-09-12
Pacific Coastal and Marine Science Center
Stephen Hartwell
Shartwell@usgs.gov}
custodian
dataset
SEG-Y header data were normalized using the "header" Sioseis processes, and a band pass filter was applied. Next, each SEG-Y file was displayed and up to 16 water-bottom time/shot-point pairs where recorded to guide the automated water-bottom picker used to mute the water column. Finally, a swell filter was applied to the data, and the results were exported as a new SEG-Y file.
Pacific Coastal and Marine Science Center
Stephen Hartwell
Shartwell@usgs.gov}
custodian
36.26521
35.30109
-120.89699
-121.91238
Central California
2011-09-12
2011-09-26
U.S. Geological Survey
Patrick Hart
hart@usgs.gov
pointOfContact
Pacific Coastal and Marine Science Center
Stephen Hartwell
Shartwell@usgs.gov
custodian
open
Unspecified
Unspecified
Unspecified
resourceProvider
Johnson, S.Y., Cochrane, G.R., Golden, N.E., Dartnell, P., Hartwell, S.R., Cochran, S.A., and Watt, J.T.
The California Seafloor Mapping Program - Providing science and geospatial data for California's State Waters
2017-01-01
published
Ocean and Coastal Management
p. 88-104
v. 140
10.1016/j.ocecoaman.2017.02.004
http://dx.doi.org/10.1016/j.ocecoaman.2017.02.004
Sliter, R. W., Triezenberg, P. J., Hart, P. E., Watt, J. T., Johnson, S.Y., and Scheirer, D. S.
High-resolution seismic reflection and marine magnetic data along the Hosgri Fault Zone, central California
2009-01-01
published
U.S. Geological Survey Open-File Report 2009-1100
https://pubs.usgs.gov/of/2009/1100/
Hydrophone_Streamer
SeismicSource_Sparker
digital
WGS84
no
CSV
2021-09-13
U.S. Geological Survey
Peter Triezenberg
ptriezenberg@usgs.gov
pointOfContact
Seismic Metadata v.1
2017-06-08