Daniel J. Kennedy
Maureen A.L. Walton
Guy R. Cochrane
Charles K. Paull
David W. Caress
Krystle Anderson
Eve Lundsten
Lisa Gilbane
20210823
Donated AUV Chirp seismic-reflection data collected during Monterey Bay Aquarium Research Institute (MBARI) cruise in April 2018 offshore of south-central California
Chirp seismic-reflection data in SEG-Y format
data release
DOI:10.5066/P97QM7NF
Pacific Coastal and Marine Science Center, Santa Cruz, California.
U.S. Geological Survey
https://doi.org/10.5066/P97QM7NF
Daniel J. Kennedy
Maureen A.L. Walton
Guy R. Cochrane
Charles K. Paull
David W. Caress
Krystle Anderson
Eve Lundsten
Lisa Gilbane
2021
Donated AUV bathymetry and Chirp seismic-reflection data collected during Monterey Bay Aquarium Research Institute cruises in 2018-2019 offshore of south-central California
data release
DOI:10.5066/P97QM7NF
Pacific Coastal and Marine Science Center, Santa Cruz, CA
U.S. Geological Survey
https://doi.org/10.5066/P97QM7NF
This dataset consists of autonomous underwater vehicle (AUV) Chirp seismic-reflection data collected in April 2018 aboard the R/V Rachel Carson, which is owned and operated by the Monterey Bay Aquarium Research Institute (MBARI). During the cruise, data were collected across eight AUV dives, six of which collected coincident bathymetry and Chirp seismic-reflection data (two dives collected Chirp seismic-reflection data only). The collection of these data was funded entirely by MBARI, and the data have been donated to the U.S. Geological Survey (USGS). The data were collected in collaboration with the USGS and the Bureau of Ocean Energy Management (BOEM) and they are located in the same study area as the collaborative California Deepwater Investigations and Groundtruthing I (Cal DIG I) project. The purpose of the overall Cal DIG I study is to assess shallow geohazards, benthic habitats, and thereby the potential for alternative energy infrastructure (namely floating wind turbines) offshore south-central California due to the study area's proximity to power grid infrastructure associated with the Morro Bay power plant. The AUV data in this portion of the data release provide ultra-high-resolution subsurface imaging of eight different patches of seafloor offshore of the south-central California coast. The AUV mapping navigation has not been accurately positioned and is considered as only partially processed.
The goal of this part of the Cal DIG I study is to collect overlapping multibeam bathymetric and Chirp seismic-reflection data Chirp offshore of south-central region of California for the purpose of improving regional models of seafloor (benthic) habitats, sediment transport, and assessing potential geologic hazards.
Additional information about the USGS field activity from which these data were derived is available online at:
http://cmgds.marine.usgs.gov/2021-603-DD
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.
20180425
20180428
Ground conditions at time data were collected.
As needed
-121.957
-121.22
35.288
35.862
USGS Metadata Identifier
USGS:5e78d619-1942-4fb3-895c-06ab6942ccc8
ISO 19115 Topic Category
oceans
elevation
geoscientificInformation
Data Categories for Marine Planning
Substrate
Distributions
USGS Thesaurus
sub-bottom profiling
sea-floor characteristics
geospatial datasets
marine geophysics
Marine Realms Information Bank (MRIB) keywords
acoustic methods
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources Program
CMHRP
Pacific Coastal and Marine Science Center
PCMSC
Monterey Bay Aquarium Research Institute
MBARI
Edgetech 2205 1-6 kHz
AUV Chirp
sub reflection profiling
Geographic Names Information System (GNIS)
Pacific Ocean
State of California
Morro Bay
NGA GEOnet Names Server (GNS)
Santa Lucia Bank
Santa Barbara Basin
none
Santa Maria Basin
Diablo Canyon
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 and Monterey Bay Aquarium Research Institute (MBARI) as the originator(s) of the dataset and in products derived from these data.
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
MBARI_AUVChirp_April2018_thumbnail.png
Bathymetry map offshore of south-central California overlaid with MBARI-donated AUV survey data in purple.
PNG
The donated data were collected aboard the R/V Rachel Carson, which is owned and operated by the Monterey Bay Aquarium Research Insitute.
SEG-Y Rev 1
The AUV system developed at MBARI has an estimated vertical depth uncertainty ranging from about 0.05 m to 2.0 m over a horizontal range of 0 to 5 m. Accuracies of final products may be lower due to total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning and datum transformations. The subbottom data were collected from a submerged platform for which both the vertical position and the altitude over the seafloor are variable. In any time section or depth section, the data start at the location of the sonar in time or depth. The trace is recorded in two-way travel time (seconds), but the sonar depth is recorded to the headers 49-52, 61-64, and 65-68 (in meters), with a scalar (divisor) of -100 in headers 69-72. The sonar depth must be converted to two-way travel time seconds using 1500 m/s which can then be added to the Chirp trace to correct for water depth and display the data in two-way travel time (seconds). Horizontal X and Y locations for the seismic profile locations are provided and stored in the SEG-Y data trace headers in header bytes 81 and 85 with a scalar of 1.
No formal logical accuracy tests were conducted.
Dataset is considered partially complete for the information presented. AUV mapping data have not had the navigation corrected. Users are advised to read the rest of the metadata record carefully for additional details.
Position data derive from an onboard inertial navigation system (INS) that has drift bounded by 0.05 percent of distance traveled when aided by Doppler Velocity Log (DVL) velocity over ground observations. The raw INS positions are adjusted in post processing so that bathymetric features match in overlapping swath data. Following the navigation adjustment relative position accuracy within the surveys is less than 2 m. The absolute position accuracy is dominated by Ultra Short Base Line (USBL) tracking of the AUV at the beginning of missions, which is less than 30 m. Bottom positions were modified using MBSystem NavAdjust to make bathymetric features in overlapping swaths and crossing swath match. Data have not been adjusted to match surface ship collected multibeam bathymetry.
Depths shown in the seismic-reflection data files are in milliseconds (round trip travel time) and are referenced to sea level. Vertical accuracy ranges between +/- 0.2 and 1 meter.
Detailed seafloor surveys were conducted using an AUV developed at the Monterey Bay Aquarium Research Institute (MBARI) specifically for seafloor mapping. The vehicle carried a Reson 7125 400kHz multibeam sonar and an Edgetech 2205 1-6 kHz Chirp subbottom profiler. The AUV was preprogrammed to proceed to more than 50 waypoints during the dives while traveling at 3 knots and maintaining an altitude of 50 m off the seafloor. Track lines were spaced 140-150 m apart. In this mode, the AUV obtains overlapping multibeam bathymetric coverage at a vertical resolution of 0.15 m and a horizontal footprint of 0.87 m, and Chirp seismic-reflection profiles with a vertical resolution of 0.11 m.
20180428
Performed minor edits to the metadata to correct typos. No data were changed
20211013
U.S. Geological Survey
Susan A. Cochran
Geologist
Mailing and Physical
2885 Mission Street
Santa Cruz
CA
95060
831-460-7545
scochran@usgs.gov
Data were collected offshore of south-central California. SEG-Y file headers contain location information.
WGS 1984 UTM Zone 10N
0.9996
-121.45
0.0
500000.0
0.0
coordinate pair
0.0001
0.0001
Meter
World Geodetic System 1984
WGS 1984
6378137.0
298.257223563
North American Vertical Datum 1988 (NAVD-88)
0.1
meters
Attribute values
value
depth in meters relative to NAVD-88
Producer defined
The partially complete AUV Chirp was originally achieved as a collection of 0.5-2.0 m resolution seismic profiles recorded in SEG-Y format.
U.S. Geological Survey
U.S. Geological Survey – CMGDS
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
Zip files contain partially processed AUV Chirp seismic-reflection data in zipped SEG-Y format. The data are divided up into folders by dive and presented by navigation line, as reflected in the individual file name(s). Download sizes range from 2.1 to 4.3 GB.
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 files contain the partially processed AUV Chirp seismic-reflection data divided into folders by dive with individual files per navigation line. Download sizes range from 2.1 to 4.3 GB.
Winzip, 7-zip, or Winrar are free software that will open .zip files.
4300
https://doi.org/10.5066/P97QM7NF
Data and metadata can be downloaded using the Network_Resource_Name link and scrolling down to the Seismic Data section.
None.
The downloadable data file has been compressed with the "zip" command and can be unzipped with Winzip (or other tool) on Windows systems. Use of SEG-Y data requires specialized software, such as ProMax and Seisworks by Landmark Geophysical; FOCUS and SeisX by Paradigm Geophysical; SPW by Parallel Geoscience; VISTA by Seismic Image Software; SeiSee by Dalmorneftegeophysica (DMNG); amongst others.
20211013
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060
831-427-4747
pcmsc_data@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998