Arnell S. Forde
20221018
2015-330-FA_trkln: Digital Chirp Subbottom Profile Trackline Data Collected During USGS Field Activity Number 2015-330-FA Offshore of Dauphin Island, Alabama, September 2015
Vector Digital Dataset (Polyline)
Arnell S. Forde
James G. Flocks
Stanley D. Locker
20221018
Archive of Chirp Subbottom Profile Data Collected in 2015 From Dauphin Island, Alabama
U.S. Geological Survey data release
doi:10.5066/P9YTIG6G
St. Petersburg, Florida
U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
https://doi.org/10.5066/P9YTIG6G
From September 16 through 23, 2015, the U.S. Geological Survey (USGS) conducted geophysical surveys to investigate the geologic controls on barrier island evolution and sediment transport offshore of Dauphin Island, Alabama. Geophysical data were collected as part of the Alabama Barrier Island Restoration Feasibility Study. This shapefile represents a line dataset of field activity number (FAN) 2015-330-FA chirp tracklines.
To aid in the registering of digital chirp seismic reflection data collected during USGS FAN 2015-330-FA.
Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-330-FA and in the Field Activity Collection System (FACS) and geophysical logs, which are included in the download file, 2015-330-FA_logs.zip (Forde and others, 2022).
20150916
20150923
ground condition
None planned
-88.328428
-88.040933
30.247492
30.158725
USGS Metadata Identifier
USGS:c5f6a328-761a-4bb1-81a3-ca0409df40dd
ISO 19115 Topic Category
geoscientificInformation
oceans
location
USGS Thesaurus
sub-bottom profiling
marine geology
geology
coastal processes
navigational data
geospatial datasets
None
trackline
barrier island mapping
seismic reflection
2015-330-FA
chirp
Common Geographic Areas
Little Dauphin Island
Alabama
Gulf of Mexico
None
The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research.
Arnell S. Forde
U.S. Geological Survey
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
aforde@usgs.gov
Data collection and processing were performed by Jim Flocks, Stan Locker (former employee), and Arnell Forde of the USGS St. Petersburg Coastal and Marine Science Center.
Environment as of Metadata Creation: Microsoft Windows 10 Version 6.2 (Build 9200); Environmental Systems Research Institute (Esri) ArcMap 10.7.1.11595; Seismic Unix (Release 44).
This dataset is from one field activity with consistent instrument calibrations.
A total of 118 seismic lines were collected during this field activity. Two test lines, 2015-330-FA.001 and 2015-330-FA.002, were collected in Mobile Bay on DOY 258. Lines 2015-330-FA, JD-260, and JD-264.003 were partial lines containing no usable data and line JD-264.010 was corrupted during acquisition; consequently, all of the preceding lines were excluded from this data release.
As the subbottom profile data were acquired, the position of the vessel was continuously determined by an Applanix POS MV Wavemaster II inertial aided navigation system (IANS), which is accurate to within 0.5-2 meters (m). Positions from the POS MV were recorded and written to seismic trace headers every second (s). The approximately 19-m offset between the chirp and GPS antenna has not been accounted for in the comma-delimited American Standard Code for Information Interchange (ASCII) navigation files and trackline map.
Navigation files were extracted from the seismic trace headers using Seismic Unix release 44 software, processed with PROJ.5.1.0 software to generate Universal Transverse Mercator (UTM) coordinates from latitude and longitude coordinates (World Geodetic System of 1984, WGS84), and then saved as ASCII text files in comma-separated values (CSV) format.
20220311
Arnell S. Forde
U.S. Geological Survey
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
aforde@usgs.gov
The reformatted, text files were imported into Esri ArcMap 10.7 software to produce a geographic representation of the subbottom profile tracklines collected within the survey area. The PointsToLine script (located in the ArcToolbox) was used to create a shapefile (.shp) in which individual chirp shotpoints were connected to form tracklines.
20220322
Arnell S. Forde
U.S. Geological Survey
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
727-502-8000
aforde@usgs.gov
Vector
String
113
0.0197878895
0.0227703311
Decimal degrees
WGS_1984
WGS_84
6378137.0
298.257223563
2015-330-FA_trkln.shp Attribute Table
Table containing attribute information associated with the dataset.
U.S. Geological Survey
FID
Internal feature number.
Esri
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
Esri
Coordinates defining the features.
Line
Trackline name
U.S. Geological Survey
The naming convention used for each subbottom line is as follows: xy_bp_mod, where 'x' is an alphanumeric identifier indicating a specific trackline (for example, JD-262 or JD-265b), 'y' is a number (such as, .001, .002, etc.) representing a new line if recording was prematurely terminated or reran for quality or acquisition problems, and 'env_bp' denotes that the seismic traces were output as an envelope and a bandpass filter was applied.
Image
Graphics Interchange Format (GIF) image name
U.S. Geological Survey
This attribute field provides the name of the subbottom profile image (.gif) that is associated with each trackline as a hyperlinked GIF; a folder containing all these .gif files, named "images", is included in 2015-330-FA_gis.zip.
Navigation files are available as ASCII delimited text files in CSV format. The final navigation files are provided in 2015-330-FA_nav.zip (Forde and others, 2022) and represent the reprojected survey shotpoint navigation, 1,000-shot-interval locations, and start of line files. The entity and attribute information provided here describes the tabular data associated with the shapefile, 2015-330-FA_trkln.shp. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the dataset.
The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.
Arnell S. Forde
U.S. Geological Survey
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
aforde@usgs.gov
This publication was prepared by an agency of the United States Government. Although these data were processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
Shapefile, MXD, KMZ, GIF
2015-330-FA_gis.zip contains the survey navigation data represented geospatially using a Google Earth keyhole markup language zipped (KMZ), Esri ArcMmap document (MXD), shapefiles, and a folder of processed subbottom profile images (GIF, accessible via hyperlinks included in the MXD). This metadata record describes the trackline locations provided in, 2015-330-FA_trkln.shp, which is one of the three Esri shapefiles included in the geographic information system (GIS) data ZIP file.
Winzip or 7zip
113.1
https://coastal.er.usgs.gov/data-release/doi-P9YTIG6G/data/2015-330-FA_gis.zip
None
This shapefile was created for use with Esri ArcGIS software. It may also be viewed with Esri public domain software Explorer for ArcGIS, GeoMapApp 3.6.14 (http://www.geomapapp.org, 2021), or other GIS software capable of importing the data.
20220912
Arnell S. Forde
U.S. Geological Survey
Geologist
Mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 502-8000
aforde@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998