2023-310-FA_sol: Digital Chirp Subbottom Profile Start of Line Data Collected During USGS Field Activity Number 2023-310-FA Offshore of Kailua, Hawaii, May 2023

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Forde, Arnell S., 20240129, 2023-310-FA_sol: Digital Chirp Subbottom Profile Start of Line Data Collected During USGS Field Activity Number 2023-310-FA Offshore of Kailua, Hawaii, May 2023:.

   This is part of the following larger work.
   Forde, Arnell S., Wei, Emily A., and Stalk, Chelsea A., 20240129, Archive of Chirp Subbottom Profile Data Collected in 2023 From Oahu, Hawaii: U.S. Geological Survey data release doi:10.5066/P9I2T4ZE, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

   Online Links:

   • https://doi.org/10.5066/P9I2T4ZE

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -157.795000
   East_Bounding_Coordinate: -157.724867
   North_Bounding_Coordinate: 21.410228
   South_Bounding_Coordinate: 21.446028
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 07-May-2023

   Ending_Date: 13-May-2023

   Currentness_Reference:

   ground condition

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: Vector Digital Dataset (Point)
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (81)
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0198168337. Longitudes are given to the nearest 0.0211353994. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS_1984.
      The ellipsoid used is WGS_84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      
7. How does the data set describe geographic features?

   2023-310-FA_sol.shp Attribute Table

   Table containing attribute information associated with the dataset. (Source: U.S. Geological Survey)

   FID

   Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.

   Shape

   Feature geometry. (Source: Esri) Coordinates defining the features.

   UTMX

   UTM-X easting coordinate (Source: Universal Transverse Mercator (WGS 1984, Zone 4N))

   Range of values
   Minimum:	624877.207
   Maximum:	632135.187

   UTMY

   UTM-Y northing coordinate (Source: Universal Transverse Mercator (WGS 1984, Zone 4N))

   Range of values
   Minimum:	2368084.86
   Maximum:	2372047.496

   Line

   Trackline name (Source: U.S. Geological Survey) Line numbers were assigned by the EdgeTech 424 chirp topside unit during data acquisition and are composed of an alphanumeric identifier and trackline number. The naming convention used for each subbottom line is as follows: xy_line#, where 'x' represents a partial FAN, 'y' denotes the survey area, which is either Marine Corps Base Hawaii (MCBH) or Marine Corps Base Hawaii Coconut Island (MCBH_CI), and 'line#' is the trackline number (for example, 2023_310_MCBH_CI_line01 and 2023_310_MCBH_line01). If recording was prematurely terminated or reran, due to quality or acquisition issues, characters (specifically "a" or "b") or sequentially increasing numbers (such as .001, .002, etc.), were manually appended to the trackline name.

   Shot

   Shotpoint number (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1
   Maximum:	1

   Lon

   Longitude (Source: World Geodetic System 1984 Geographic Coordinate System)

   Range of values
   Minimum:	-157.795
   Maximum:	-157.724867

   Lat

   Latitude (Source: World Geodetic System 1984 Geographic Coordinate System)

   Range of values
   Minimum:	21.410228
   Maximum:	21.446028

   YEAR

   Year of data acquisition (Source: U.S. Geological Survey)

   Range of values
   Minimum:	2023
   Maximum:	2023

   DOY_HR_MIN

   day of year:hour:minute:second (Source: U.S. Geological Survey) Day of year, hour, minute and second of data acquisition, in Coordinated Universal Time.

   Entity_and_Attribute_Overview:

   The entity and attribute information provided here describes the tabular data associated with the shapefile, 2023-310-FA_sol.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. Navigation files are available as ASCII delimited text files in CSV format. The final navigation files are provided in 2023-310-FA_nav.zip (Forde and others, 2023) and represent the reprojected survey shotpoint navigation, 1,000-shot-interval locations, and start of line files.

   Entity_and_Attribute_Detail_Citation:

   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.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Arnell S. Forde
2. Who also contributed to the data set?
   Data collection and processing were performed by Chelsea Stalk, Emily Wei, and Arnell Forde of the USGS St. Petersburg Coastal and Marine Science Center.
3. To whom should users address questions about the data?
   Arnell S. Forde

   U.S. Geological Survey

   Geologist

   600 4th Street South

   St. Petersburg, FL
   

   USA

   727-502-8000 (voice)

   aforde@usgs.gov

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 07-Aug-2023 (process 1 of 2)

   Navigation files were extracted from the seismic trace headers using Seismic Unix release 44 software (https://github.com/JohnWStockwellJr/SeisUnix) and custom scripts, processed with PROJ.5.1.0 software (https://proj.org/) to generate Universal Transverse Mercator (UTM) Zone 4 North (N) 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. A custom script was created to produce unique navigation fixes for each line and for all instances where the shot was equal to 1, that data point was output into a new text file. All the shotpoints with a shot value equal to 1 were concatenated in the CSV file, 2023-310-FA_sol.csv, which represents the start of each trackline collected during the survey. Person who carried out this activity:
   

   Arnell S. Forde

   U.S. Geological Survey

   Geologist

   600 4th Street South

   St. Petersburg, FL
   

   USA

   727-502-8000 (voice)

   aforde@usgs.gov

   Date: 10-Oct-2023 (process 2 of 2)

   The reformatted text file was imported into Esri ArcMap 10.8 software to produce a geographic representation of the shotpoint data collected within the survey area. ArcMap was used to create a point shapefile containing start of line locations for all chirp tracklines. Person who carried out this activity:
   

   Arnell S. Forde

   U.S. Geological Survey

   Geologist

   600 4th Street South

   St. Petersburg, FL
   

   USA

   727-502-8000 (voice)

   aforde@usgs.gov

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   The validity or accuracy of marine subbottom profiles is highly qualitative and depends on equipment and operating condition variables. Visual inspection of the shapefile created from the navigation data did not show any major anomalies.
2. How accurate are the geographic locations?
   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 IANS were recorded and written to the seismic trace headers every 0.20 seconds, with unique navigation fixes being recorded every second. The approximately 3-meter offset between the chirp and vessel's IANS reference point has not been accounted for in the comma-delimited American Standard Code for Information Interchange (ASCII) navigation files and trackline map.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   A total of 84 seismic lines were collected during this field activity. Three lines and their associated navigation were excluded from this data release (Forde and others 2023), due to equipment or acquisition issues, resulting in unusable data files.
5. How consistent are the relationships among the observations, including topology?
   This dataset is from one field activity with consistent instrument calibrations. No seismic reflection data were collected on DOY 128 (May 8, 2023) or 129 (May 9, 2023).

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   Arnell S. Forde

   U.S. Geological Survey

   Geologist

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727) 502-8000 (voice)

   aforde@usgs.gov
2. What's the catalog number I need to order this data set?
3. What legal disclaimers am I supposed to read?
   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.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:

     2023-310-FA_gis.zip (Forde and others, 2023) contains the survey navigation data represented geospatially using a Google Earth Keyhole Markup Language Zipped (KMZ), Esri map document (MXD), shapefiles, and a folder of processed subbottom profile images (accessible via hyperlinks included in the MXD). This metadata record describes the start of line locations provided in 2023-310-FA_sol.shp, which is one of three Esri shapefiles included in the geographic information system (GIS) data ZIP file. in format Shapefile, MXD, KMZ, GIF Size: 20.3

     Network links:

     https://coastal.er.usgs.gov/data-release/doi-P9I2T4ZE/data/2023-310-FA_gis.zip

   • Cost to order the data: None

5. What hardware or software do I need in order to use the data set?
   This shapefile was created for use with Esri ArcGIS 10.8 software. It may also be viewed with QGIS (https://www.qgis.org/en/site/, 2023), GeoMapApp 3.6.15 (https://www.geomapapp.org, 2023), or other GIS software capable of importing the data.

Who wrote the metadata?

Dates:

Last modified: 29-Jan-2024

Metadata author:

Arnell S. Forde

U.S. Geological Survey

Geologist

600 4th Street South

St. Petersburg, FL

USA

(727) 502-8000 (voice)

aforde@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)