Video transects of the sea floor collected by the U.S. Geological Survey on Stellwagen Bank during three surveys aboard the R/V Auk, September 2020 to August 2021

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?
   Valentine, Page C., 20230321, Video transects of the sea floor collected by the U.S. Geological Survey on Stellwagen Bank during three surveys aboard the R/V Auk, September 2020 to August 2021: data release DOI:10.5066/P9G7QARQ, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

   Online Links:

   • https://doi.org/10.5066/P9G7QARQ
   • https://sciencebase.gov/catalog/item/633c9861d34e900e86cf1ab4

   This is part of the following larger work.
   Valentine, Page C., and Cross, VeeAnn A., 2023, Sea-floor Sediment Samples, Seabed and Sample Imagery, and CTD Instrument Data Collected on Stellwagen Bank from September 2020 to August 2021: data release DOI:10.5066/P9G7QARQ, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.5066/P9G7QARQ
   • https://sciencebase.gov/catalog/item/633c8e2dd34e900e86cf1a93

   Other_Citation_Details:

   Suggested citation: Valentine, P.C., and Cross, V.A., 2023, Sea-floor sediment samples, seabed and sample imagery, and CTD instrument data collected on Stellwagen Bank from September 2020 to August 2021: U.S. Geological Survey data release, https://doi.org/10.5066/P9G7QARQ .

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -70.56283
   East_Bounding_Coordinate: -70.11801
   North_Bounding_Coordinate: 42.44029
   South_Bounding_Coordinate: 42.09603
   

3. What does it look like?

   https://www.sciencebase.gov/catalog/file/get/633c9861d34e900e86cf1ab4?name=video_driftlines_2020-2021_browse.jpg&allowOpen=true (JPEG)

   Browse graphic showing the video drift lines.

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 24-Sep-2020

   Ending_Date: 04-Aug-2021

   Currentness_Reference:

   Ground condition of when data were collected. These data were collected during three separate surveys, with the following ranges of dates for each survey: field activity 2020-012-FA: 20200924 to 20200925; field activity 2021-016-FA: 20210721 to 20210723; and field activity 2021-017-FA: 20210802 to 20210804.

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

   Geospatial_Data_Presentation_Form: vector digital dataset (polyline)
   

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):
      • String (168)
   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 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      
7. How does the data set describe geographic features?

   video_driftlines_2020-2021.shp

   polyline shapefile of video drift transects for three field activities (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.

   ID

   Unique identifier for each record per field activity. This identifier was assigned during the initial polyline creation from the Python script. Since the file combines more than one field activity, values can be duplicated. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	92

   Survey

   Name or number of cruise on which sample collected. The cruise identifier is in the format YYYY-XXX-FA where YYYY is the survey year, XXX is the survey number of that year, and FA is Field Activity. (Source: U.S. Geological Survey) Character string.

   Station

   Sample or station name or number as assigned in the field by the Chief Scientist. (Source: U.S. Geological Survey) Character set. Although numeric, stations could have a decimal number indicating a reoccupation of a station.

   Year

   Year the station was occupied. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	2020
   Maximum:	2021

   JD

   Julian day of the video drift based on the date in UTC time at the deployment of the SEABOSS. Julian day is the integer number representing the interval of time in days since January 1 of the year of collection. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	202
   Maximum:	269

   LineStart

   Start time of the video drift when the SEABOSS reached the seabed as recorded in the log book, in UTC time in HH:MM:SS. (Source: U.S. Geological Survey) Number represented as a text field.

   LineEnd

   End time of the video drift when the SEABOSS left the seabed as recorded in the log book, in UTC time in HH:MM:SS. (Source: U.S. Geological Survey) Number represented as a text field.

   GPSStart

   Time in the GPS navigation file that is closest to the start time of the video drift as recorded in the log book. UTC time in HH:MM:SS. (Source: U.S. Geological Survey) Number represented as a text field.

   GPSEnd

   Time in the GPS navigation file that is closest to the end time of the video drift as recorded in the log book. UTC time in HH:MM:SS. (Source: U.S. Geological Survey) Number represented as a text field.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Page C. Valentine
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey

   Attn: Page C. Valentine

   Research Geologist

   384 Woods Hole Rd.

   Woods Hole, MA
   

   USA

   (508) 548-8700 x2239 (voice)

   (508) 457-2310 (FAX)

   whsc_data_contact@usgs.gov

   Contact_Instructions:

   The contact email address is a generic address in the event the person is no longer with the USGS.

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: 2021 (process 1 of 5)

   Seabed video imagery was collected using two battery-operated, high-definition (1920 x 1080 pixels) GoPro digital video cameras and a SeaViewer high-definition (1920 x 720 pixels) video camera mounted on the SEABOSS. See the cross-references for a description of the SEABOSS (Blackwood and Parolski, 2001; Valentine and others, 2000). The SeaViewer camera had a live feed to the surface. It was mounted a little higher on the frame than the GoPros and was used to observe obstacles, like gill nets and lobster gear, in order to avoid entanglement. One of the GoPro cameras was selected as the primary source of video. In case of camera failure, the additional GoPro and SeaViewer cameras provided backup video.
   As the SEABOSS drifted over the seabed, the cameras imaged the seabed at a rate of 60 frames per second from an altitude of ~1 meter. Lighting was provided by two battery-operated Keldan LED dive lights. Each light provided a light flux of up to 9000 lumens at a correlated color temperature of 5000 kelvins. Two parallel red lasers mounted 20 centimeters apart provided a scale in the video images.
   GoPro video imagery includes the launch of the SEABOSS, transit through the water column, and the drift over the seabed. The duration of 168 individual video files ranges 2 to 13.5 minutes. Video files are archived in .MP4 format and range in size from 0.2 to 3.0 gigabytes.
   These video files are not available as part of this data release. Video files are archived at the USGS Woods Hole Coastal and Marine Science Center, 384 Woods Hole Road, Woods Hole, MA 02543.
   The position (latitude and longitude) and time of the start of the video drift was recorded from the navigation receiver by hand in the cruise log book (see the dataset cruise_logs_2020-2021 from the larger work citation of this data release). In some cases the time of the deployment of the SEABOSS is recorded, but in all cases, the time when the system reached the seabed, and when it left the seabed are recorded - which corresponds to the video drift transects. A video transect represents where the SEABOSS drifted and collected video of the seabed, not where the entire video was recorded at a station, which also includes the launch of the SEABOSS and descent through the water column. Latitude and longitude positions recorded by hand in the log book were later adjusted to match the data recorded in the GPS navigation file based on time.
   Data were collected from 2020 to 2021 with the process date representing the most recent acquisition year. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Page C. Valentine

   Research Geologist

   384 Woods Hole Rd.

   Woods Hole, MA
   

   USA

   (508) 548-8700 x2239 (voice)

   (508) 457-2310 (FAX)

   pvalentine@usgs.gov

   Date: 2022 (process 2 of 5)

   The original raw GGA navigation was run through an AWK script (awkauk_rndissue, on a machine running Cygwin - www.cygwin.com) to reformat the latitudes and longitudes into decimal degrees and output the data into a comma-delimited text file with the following columns of information: latitude (decimal degrees out to five decimal places), longitude (decimal degrees out to five decimal places), hour, minute, second, Julian day, year. The Julian day was determined by the original date in the filename of the navigation file as the GGA string does not contain any date information. The script made sure to round the latitude and longitude values to five decimal places in the same way that Excel would round the values. The AWK script also made sure that there were no duplicate records in terms of time, such as two navigation points recorded at 16:38:23. Depending on the boat drift rate, navigation fixes carried out to only five decimal places could have duplicate fixes. The individual navigation files were concatenated into a single file for each field activity in order of acquisition. This process was repeated for all three field activities. This process step and the remaining process steps were performed by the same person - VeeAnn A. Cross. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: VeeAnn A. Cross

   Marine Geologist

   384 Woods Hole Road

   Woods Hole, MA
   

   508-548-8700 x2251 (voice)

   508-457-2310 (FAX)

   vatnipp@usgs.gov

   Date: 2022 (process 3 of 5)

   Another AWK script (awkdrift_pullstartend) was run on the station summary CSV file to extract the following columns of information: station, Julian day of video start, UTC time of video start, Julian day of video end, UTC time of video end, and year. This same process was repeated for all three field activities.

   Date: 2022 (process 4 of 5)

   A Python script (driftlog_gui_v6.py) run from Python IDLE version 2.7.18 on Windows 10 was used to extract all the navigation points from the navigation file based on the start and end time of the video drift and combine these into polylines. Ideally, there is a match of the same time (with a corresponding navigation fix) in the GPS file to the start and end video times recorded in the log book. However, if this situation does not exist, then the closest (in time) navigation record to the start and end time of the video transect is used, along with all the navigation points in between those two times. Since location in the log book were updated based on the navigation files, these values should match. These extracted points were then combined into a polyline shapefile. The resulting shapefile has a polyline for every video drift on a single cruise. Based on the navigation system, the coordinate system of the dataset was set to geographic coordinates, WGS 84.

   Date: 2022 (process 5 of 5)

   The three individual polyline shapefiles were then combined in QGIS 3.16.7 using the Merge Vector Layers tool. The output dataset was set to a shapefile. Two fields created by QGIS as a result of the merge (layer and path) were removed as unnecessary information.

3. What similar or related data should the user be aware of?
   Blackwood, D.S., and Parolski, K.F., 2001, Seabed observation and sampling system: Sea Technology v. 42, no. 2, p. 39-43.

   Valentine, P., Blackwood, D., and Parolski, K., 2000, Seabed observation and sampling system: U.S. Geological Survey Fact Sheet FS-142-00, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.3133/fs14200
   • https://pubs.usgs.gov/fs/fs142-00/

   Valentine, P.C., and Cross, V.A., 2019, Location and analyses of sediment samples collected on Stellwagen Bank off Boston, Massachusetts from November 5, 2013 to April 30, 2019 on U.S. Geological Survey field activities: data release DOI:10.5066/P9FWFLPD, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.5066/P9FWFLPD
   • https://www.sciencebase.gov/catalog/item/5d95153ee4b0c4f70d10a4f7

   Other_Citation_Details:

   This publication includes the grain-size analyses of the sediment samples collected on 20 other field activities.

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?
   The location information for the video transects was acquired from a satellite navigation receiver (Furuno Satellite Compass SC-30, GPS receiver) in geographic coordinates (World Geodetic System of 1984 [WGS 84]) with a horizontal accuracy of 10 m. Field activity 2020-012-FA acquired navigation at two-second intervals on September 24 and five-second intervals on September 25. Field activity 2021-016-FA acquired navigation at a two-second interval. Field activity 2021-017-FA acquired navigation at a two-second interval. The navigation antenna was located 5.3 m forward of the SEABed Observation and Sampling System (SEABOSS) deployment location. This offset was not accounted for in the navigation acquisition, so navigation fixes represent antenna location. The SEABOSS may also drift away from the survey vessel when deployed to the sea floor.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   This represents the video trackline information for every video drift line obtained during the three field activities. of the 169 stations occupied by the SEABOSS during the three surveys, video imagery was collected at 168 sites. There is no video for station 4973 (survey 2021-012-FA).
5. How consistent are the relationships among the observations, including topology?
   Each record within the shapefile has the same information and was derived in the same manner.
   The end of the video transect sometimes coincides with the sample acquisition, but not always.
   All the field activities took place on the Stellwagen Bank National Marine Sanctuary's research vessel, R/V Auk. Although these data represent three separate field activities, the set-up and acquisition on all the cruises is consistent with the exception of the navigation - which was sometimes acquired at 2-second intervals and sometimes at 5-second intervals. A video transect represents where the SEABOSS drifted and collected video of the seabed, not where the entire video was recorded at a station, which also includes the launch of the SEABOSS and descent through the water column.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   USA

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? This dataset contains the video drift lines shapefile (video_driftlines_2020-2021.shp and other files associated with a shapefile). The dataset also includes the browse graphic (video_driftlines_2020-2021_browse.jpg) and the FGDC CSDGM metadata in XML format.
3. What legal disclaimers am I supposed to read?
   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 for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	The dataset contains the video drift transects polyline shapefile, browse graphic, and FGDC CSDGM metadata. in format Shapefile (version QGIS 3.16.7) Size: 1
     Network links:	https://www.sciencebase.gov/catalog/file/get/633c9861d34e900e86cf1ab4 https://www.sciencebase.gov/catalog/item/633c9861d34e900e86cf1ab4 https://doi.org/10.5066/P9G7QARQ

     Data format:	Web mapping services of the station summary data - video_driftlines_2020-2021. in format WMS (version 1.3)
     Network links:	https://www.sciencebase.gov/catalogMaps/mapping/ows/633c9861d34e900e86cf1ab4?service=wms&request=getcapabilities&version=1.3.0

     Data format:	Web feature services of the station summary data - video_driftlines_2020-2021. in format WFS (version 1.0)
     Network links:	https://www.sciencebase.gov/catalogMaps/mapping/ows/633c9861d34e900e86cf1ab4?service=wfs&request=getcapabilities&version=1.0.0

   • Cost to order the data: none

5. What hardware or software do I need in order to use the data set?
   The ZIP file contains data in Esri shapefile format. The user must software capable of uncompressing the ZIP file and reading the data format.

Who wrote the metadata?

Dates:

Last modified: 21-Mar-2023

Metadata author:

U.S. Geological Survey

Attn: VeeAnn A. Cross

Marine Geologist

384 Woods Hole Rd.

Woods Hole, MA

508-548-8700 x2251 (voice)

508-457-2310 (FAX)

whsc_data_contact@usgs.gov

Contact_Instructions:

The metadata contact email address is a generic address in the event the person is no longer with the USGS.

Metadata standard:

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