Station and data summary for data collected by the U.S. Geological Survey on Stellwagen Bank during three surveys aboard the R/V Auk, September 2020 to August 2021

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Title:
Station and data summary for data collected by the U.S. Geological Survey on Stellwagen Bank during three surveys aboard the R/V Auk, September 2020 to August 2021
Abstract:
These data are a part of the effort to map geologic substrates of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts. The overall goal is to develop high-resolution (1:25,000) interpretive maps, based on multibeam sonar data and seabed sampling, showing surficial geology and seabed sediment dynamics. The work was conducted in collaboration with the Stellwagen Bank National Marine Sanctuary, and the data collected will aid research on the ecology of fish and invertebrate species that inhabit the region. The Sanctuary's research vessel, R/V Auk, visited a total of 169 locations on Stellwagen Bank during three separate surveys from September 2020 to August 2021. During these surveys a customized Van Veen grab sampler (SEABOSS) equipped with a video camera and a CTD was deployed in drift mode to collect sediment for grain-size analysis, video imagery of the seabed, and measurements of water column properties including temperature, salinity, density, and fluorescence.
Supplemental_Information:
Additional information regarding the field activities associated with these data can be obtained from the following locations https://cmgds.marine.usgs.gov/fan_info.php?fan=2020-012-FA, https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-016-FA, and https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-017-FA .
  1. How might this data set be cited?
    Valentine, Page C., 20230321, Station and data summary for data 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:

    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:

    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: -70.56265
    East_Bounding_Coordinate: -70.11801
    North_Bounding_Coordinate: 42.43998
    South_Bounding_Coordinate: 42.09603
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/633c961cd34e900e86cf1aae?name=2020-2021_station_data_summary_browse.jpg&allowOpen=true (JPEG)
    Browse graphic showing the station locations.
  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 and tabular digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (169)
    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.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Local surface
      Depth_Resolution: 1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    2020-2021_station_data_summary in Excel spreadsheet, CSV, and shapefile format
    The Microsoft Excel spreadsheet has a header in row 1 explaining the columns of information, header names in row 2, and header names that are appropriate for incorporation into a GIS (shorter names, no punctuation) in row 3. The spreadsheet gives basic station information (location, cruise, occupation date and time), as well as additional information indicating what data were collected at each location. The labels below are the shapefile and CSV row headers with the first part of the attribute definition the longer header on row 2 of the Excel spreadsheet. The software-generated FID and Shape attributes listed below are only included in the shapefile and are absent from the Excel spreadsheet and CSV file and are not visible in all GIS software packages. (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.
    FIELD_NO
    USGS station: Sample 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.
    DEPTH_M
    Water depth, m: Depth in meters of the station based on the ship echosounder. Recorded in the log book at the time of deployment of the SEABOSS. The values were rounded to the nearest meter to account for ship motion. (Source: U.S. Geological Survey)
    Range of values
    Minimum:23
    Maximum:67
    Units:meters
    VESSEL
    Vessel name: The name of the ship that the field activity used for the cruise. (Source: U.S. Geological Survey) Character string.
    CRUISE_ID
    WHCMSC field activity number: The field activity number assigned to the cruise by the Woods Hole Coastal and Marine Science Center (WHCMSC) on which the sample was collected. The cruise identifier is in the format YYYY-XXX where YYYY is the survey year, and XXX is the survey number of that year. (Source: U.S. Geological Survey) Character string.
    UTC_DATE
    Date, UTC: The date of the row of data collection based on UTC (Coordinated Universal Time) time. In the Excel spreadsheet, the date has the format of D-M-YYYY where D is the numeric day, M is the month abbreviation, and YYYY is the year. The date is based on the deployment of the SEABOSS. (Source: U.S. Geological Survey) Character string.
    UTC_JD
    Julian Day, UTC: Julian day of data collection based on the deployment of the SEABOSS in UTC time. 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
    UTC_JDTIME
    Station occupation date and time, DDD:HH:MM:SS, UTC: Station occupation date and time with Julian day and time in UTC. The format is DDD:HH:MM:SS where DDD is the Julian day, HH is hour, MM is minutes, and SS is seconds. Julian day is the integer number representing the interval of time in days since January 1 of the year of collection. This time corresponds to when the sediment sample was collected (if one was collected). If a sediment sample was not collected, this time represents the end of the video drift. (Source: U.S. Geological Survey) Character string.
    TIMEZONE
    Study area time zone: The time zone in which the study area is located. (Source: U.S. Geological Survey)
    ValueDefinition
    EDTEastern Daylight Time. To derive EDT, subtract 4 hours from the UTC time.
    STA_LAT
    Station location, Lat N, decimal degrees: Latitude coordinate in decimal degrees (WGS 84) of station location. The position represents the location of the sediment sample (if collected). If a sediment sample was not collected, the position represents the end of the video drift. (Source: U.S. Geological Survey)
    Range of values
    Minimum:42.09603
    Maximum:42.43998
    Units:decimal degrees
    STA_LON
    Station location, Lon W, decimal degrees: Longitude coordinate in decimal degrees (WGS 84) of station location. West longitudes are recorded as negative values. The position represents the location of the sediment sample (if collected). If a sediment sample was not collected, the position represents the end of the video drift. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.56265
    Maximum:-70.11801
    Units:decimal degrees
    STIME_VID
    Video drift start time, UTC, HHMMSS: Start time of the video drift when the SEABOSS reached the seabed, in UTC time in HHMMSS. (Source: U.S. Geological Survey) Text field presented as a number.
    ETIME_VID
    Video drift end time, UTC, HHMMSS: End time of the video drift when the SEABOSS left the seabed, in UTC time in HHMMSS. (Source: U.S. Geological Survey) Text field presented as a number.
    SLAT_VID
    Video drift start Lat N, decimal degrees: Latitude coordinate in decimal degrees (WGS 84) at the start of the station video drift when the SEABOSS reached the seabed. (Source: U.S. Geological Survey)
    Range of values
    Minimum:42.0963
    Maximum:42.44029
    Units:decimal degrees
    SLON_VID
    Video drift start Lon W, decimal degrees: Longitude coordinate in decimal degrees (WGS 84) at the start of the station video drift when the SEABOSS reached the seabed. West longitude is recorded as negative values. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.56283
    Maximum:-70.12003
    Units:decimal degrees
    ELAT_VID
    Video drift end Lat N, decimal degrees: Latitude coordinate in decimal degrees (WGS 84) at the end of the station video drift when the SEABOSS left the seabed. (Source: U.S. Geological Survey)
    Range of values
    Minimum:42.09603
    Maximum:42.43998
    Units:decimal degrees
    ELON_VID
    Video drift end Lon W, decimal degrees: Longitude coordinate in decimal degrees (WGS 84) at the end of the station video drift when the SEABOSS left the seabed. West longitude is recorded as negative values. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.56265
    Maximum:-70.11801
    Units:decimal degrees
    SAMP_LAT
    Sediment sample location, Lat N, decimal degrees: Latitude coordinate in decimal degrees (WGS 84) of the sediment sample location. A value of 9999 indicates no sample location because no sample was collected. (Source: U.S. Geological Survey)
    Range of values
    Minimum:42.09603
    Maximum:42.43998
    Units:decimal degrees
    SAMP_LON
    Sediment sample location, Lon W, decimal degrees: Longitude coordinate in decimal degrees (WGS 84) of the sediment sample location. West longitude is recorded as negative values. A value of 9999 indicates no sample location because no sample was collected. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.56265
    Maximum:-70.11801
    Units:decimal degrees
    VIDEO
    Video imagery collected: The value of this attribute indicates if seabed video was recorded at the station. The value "y" indicates that video was recorded, "n" indicates no video was recorded. (Source: U.S. Geological Survey) Boolean character set.
    VIDEOFG
    Video frame grabs collected: The value of this attribute indicates if a video frame grab was acquired at the station. The value "y" indicates that a frame was captured, "n" indicates no frame was captured. (Source: U.S. Geological Survey) Boolean character set.
    CTD_PR
    CTD profile data collected: The value "du" indicates that CTD downcast and upcast data were collected, "n" indicates no CTD cast was taken. (Source: U.S. Geological Survey) Boolean character set.
    SEDSAMP
    Sediment sample collected: The value of this attribute indicates if a seabed sample was successfully collected at the station. The value "y" indicates that a sample was collected, "n" indicates no sample was collected. (Source: U.S. Geological Survey) Boolean character set.
    SEDSAMPPH
    Sediment sample photo collected: The value of this attribute indicates if a photo of the sediment sample surface in the SEABOSS grab sampler was taken at the station. The value "y" indicates that a photo was taken, "n" indicates no photo was taken. Please note that photos were sometimes taken of unsuccessful sediment samples that were discarded. (Source: U.S. Geological Survey) Boolean character set.
    AREA
    Region: General geographic area of data collection. This can be an abbreviation, such as SBNMS for Stellwagen Bank National Marine Sanctuary. (Source: U.S. Geological Survey) Character string.
    Entity_and_Attribute_Overview:
    The attribute label is the abbreviated label in the third row of the Excel file that is more compatible with importing the dataset into a GIS. The first part of the attribute definition is the longer label of the column that is in the second row of the Excel spreadsheet.
    The Excel spreadsheet has the following information in the first row describing the spreadsheet:
    [Cruise station and data summary: column A, USGS station number; column B, water depth, meters; column C, vessel name; column D, WHCMSC field activity number; column E, date, UTC; column F, Julian Day, UTC; column G, station occupation date and time, UTC (for Eastern Daylight Time subtract 4 hours; for Eastern Standard Time, subtract 5 hours); column H, study area time zone; column I, station location, latitude north, decimal degrees; column J, station location, longitude west, decimal degrees (station location is the sample location, if collected; otherwise it is the video drift end location); column K, video drift start time, UTC; column L, video drift end time, UTC; column M, start of video drift, latitude north, decimal degrees; column M, start of video drift, longitude west, decimal degrees; column O, end of video drift, latitude north, decimal degrees; column P, end of video drift, longitude west, decimal degrees; column Q, sediment sample location, latitude north, decimal degrees; column R, sediment sample location, longitude west, decimal degrees; column S, video imagery collected; column T, video frame grabs collected; column U, CTD profile collected; column V, sediment sample collected; column W, sediment sample photo collected; column X, geographic region [abbreviations: DDD, Julian Day; EDT, Eastern Daylight Time; EST, Eastern Standard Time; H, hour; M, minute; S, second; lat, latitude; lon, longitude; WHCMSC, USGS Woods Hole Coastal and Marine Science Center; SBNMS, Stellwagen Bank National Marine Sanctuary; UTC, Coordinated Universal Time (Greenwich Mean Time, Zulu time); y, yes; n, no; du, downcast and upcast data; 9999, no sample location because no sample collected]
    The CSV file has the same information and the same column definitions except the first two rows included in the Excel file are omitted (information describing the spreadsheet and longer column labels). Likewise the shapefile is the same as the CSV file, with the addition of shapefile specific attributes that are software generated.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

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?

The record of data acquired at each station provides water depths, times, and coordinates of video imagery and samples to aid in the interpretation and mapping of seabed substrate types. This data summary file indicates what data are available for the interpretation at each station.

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)
    Sediment sampling methods:
    As a part of the process of mapping the sea floor, the USGS developed the SEABed Observation and Sampling System (SEABOSS) to collect samples and video and photographic images of the seabed to aid in the interpretation of seabed sonar imagery. A modified Van Veen sediment grab sampler is mounted in the center of the SEABOSS frame, which ensures the sampler is properly oriented on the seabed when a sample is collected. Before deployment, the sampler bucket jaws are opened by collapsing the extended arms to a near-horizontal position and locking them in place with two catches. The sampler operates passively to sample the seabed; it is not spring loaded.
    To collect a sediment sample, the SEABOSS frame was lowered gently onto the seabed, reducing tension on the cable, which caused the two locking catches to be automatically released by gravity. As the cable was retrieved, the grab sampler arms were pulled upward, closing the bucket around the sediment, and the SEABOSS was lifted off the seabed.
    The SEABOSS was retrieved and set upon a wooden platform that kept the sampler bucket and camera systems above the deck. The sampler arms were held in the upright position manually or by tension on the cable, the two doors on the upper side of the bucket were opened, and the sediment surface was photographed before the sediment was removed. For this project, the upper 2 cm of sediment, representing the surface of the seabed, were removed with a rectangular shovel 2-cm deep and stored in a plastic bag for grain-size analysis. The remaining sediment was dumped into a tray on the deck below the sampler, after which the sampler was washed in preparation for sampling at the next site. The dumped sediment was sifted through for sandlance, which if found, were bagged and frozen for additional analyses by the SBNMS scientists. Further information on the SEABOSS can be found in Blackwood and Parolski (2001) and Valentine and others (2000).
    Grain-size analyses of the sediment samples were performed at the sediment laboratory at the USGS Woods Hole Coastal and Marine Science Center in Woods Hole, Massachusetts, by using a standard suite of analytical methods (Poppe and others, 2014). This laboratory has been in operation since 1963 and has analyzed many thousands of sediment samples collected by the USGS in New England. The grain-size analyses of the sediment samples collected during these field activities is available from the larger work citation.
    Video methods and data availability:
    Seabed videos were collected using two battery-operated, high-definition (1920 x 1080 pixels) GoPro digital video camera mounted on the SEABOSS. The SEABOSS system also had a SeaViewer high-definition (1920 x 720 pixels), video camera attached to it with 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 for this data release. In case of camera failure, the additional GoPro and SeaViewer cameras provided backup video. As the SEABOSS drifted over the seabed, the GoPro 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 and recovery of the SEABOSS, transit through the water column, and the drift over the seabed. The duration of 168 individual video files ranges from 2 to 13.5 minutes. Video files are archived in .MP4 format and range in size from 0.2 to 3.0 gigabytes. The video files are not part of this data release, but they are archived at the USGS Woods Hole Coastal and Marine Science Center.
    The position (latitude and longitude) and time were 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). Consistently, the time when the SEABOSS reached the seabed, when a grab sample was attempted, and when it left the seabed was recorded in the log book. Some activities also recorded the time the instrument was deployed and recovered. Latitude and longitude positions recorded by hand in the log book were later adjusted to match the data recorded in the GPS navigation file. Video was recorded during the descent through the water column (1-2 minutes), during the drift over the seabed, and during the ascent to the surface.
    Video frame grabs were captured to show typical images of the seabed. These images are available from the Larger Work citation.
    The station position (latitude and longitude) represents the location of the sediment sample (if collected) as noted in the cruise log and then adjusted, if necessary, based on the GPS navigation data. If a sediment sample was not collected, the station position represents the end of the video drift.
    Water depth was determined using a Simrad ES60, 120 kHz, single beam echosounder using a dual frequency 120-25 kHz transducer, which detects the seabed to a depth of 800 m. Depth values were recorded in a log book at the time of deployment of the SEABOSS and were rounded to the nearest meter to account for ship motion.
    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: 2021 (process 2 of 5)
    This information was manually entered into a Microsoft Excel (2016) spreadsheet with a column for each piece of information as described in the entity and attribute section of the metadata. The first row is an explanation header, the second row contains descriptive column headers, and the third row contains brief column headers that are compatible with importing the data into a GIS. The first and second rows do not appear in the CSV or shapefile versions of the dataset.
    Data were collected from 2021 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 3 of 5)
    The individual Excel files from each cruise were combined into a single Excel file in Microsoft Excel O365. The data rows from each cruise were appended within the single file in chronological order. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 2022 (process 4 of 5)
    The spreadsheet was opened in Microsoft Excel (O365). The first row (the explanation header) and the second row (descriptive column headers) were deleted, and the third row (brief column headers that are compatible with importing the data into a GIS) was retained. Then the spreadsheet was exported as an MS-DOS CSV. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 2022 (process 5 of 5)
    Using QGIS 3.16.7, the CSV file was converted to a shapefile within QGIS using Layer - Add Layer - Add delimited text layer. The CSV file was selected, with the x-coordinate set to STA_LON and the y-coordinate set to STA_LAT. The coordinate system of the input coordinates was set to the geographic coordinate system GCS_WGS_1984. Once the XY layer was added to QGIS, the data were then converted to a shapefile by right-clicking on the layer in the contents pane - Export - Save Features As. All of the features were exported using the layer's source data for the coordinate system. The output shapefile was exported as 2021-2021_station_data_summary.shp. 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
  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:

    Poppe, L.J., McMullen, K.Y., Williams, S.J., and Paskevich, V.F., 2014, USGS east-coast sediment analysis: Procedures, database, and GIS data: Open-File Report 2005-1001, U.S. Geological Survey, Reston, VA.

    Online Links:

    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:

    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 stations 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?
    Water depth relative to the local sea surface was determined using a Simrad ES60, 120 kHz, single beam echosounder using a dual frequency 120-25 kHz transducer, which detects the seabed to a depth of 800 m. Depth values were rounded to the nearest meter to account for ship motion. The water depths were transcribed manually, so some errors could be associated with that process. The depth is relative to the transducer location, no adjustment was made for tides or transducer depth.
  4. Where are the gaps in the data? What is missing?
    These station locations and data collection information represent all the station information available for all 169 stations visited during the three field activities. Not every station collected sediment samples, vidoe imagery, photos of acquired samples, or CTD data. The details of which stations acquired what information is available throught the attributes of the dataset. Of note, although station 5023 indicates the presence of CTD data, the file itself is extremely small and probably does not represent a full deployment.
  5. How consistent are the relationships among the observations, including topology?
    The same information was recorded for each station occupied. The station locations (latitude and longitude values) are based on information recorded in the cruise log book and later adjusted to match the data recorded in the GPS navigation file based on time.
    All the field activities were conducted 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.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints None.
Use_Constraints Not to be used for navigation.
  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 Excel spreadsheet with the station summary information (2020-2021_station_data_summary.xlsx), a CSV file of the same information with a GIS compatible header row (2020-2021_station_data_summary.csv), and the shapefile created from the CSV file (2020-2021_station_data_summary.shp and the other files associated with a shapefile). The dataset also includes the browse graphic (2020-2021_station_data_summary_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?
  5. What hardware or software do I need in order to use the data set?
    The ZIP file contains data in XLSX, CSV, and Esri shapefile formats. The user must have software capable of uncompressing the ZIP file and reading the data formats.

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)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P9G7QARQ/2020-2021_station_data_summary_meta.faq.html>
Generated by mp version 2.9.51 on Tue Mar 21 11:09:10 2023