Online Links:
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| Range of values | |
|---|---|
| Minimum: | 25 |
| Maximum: | 36 |
| Units: | meters |
| Value | Definition |
|---|---|
| EST | Eastern Standard Time. To derive EST, subtract 5 hours from the UTC time. |
| Range of values | |
|---|---|
| Minimum: | 42.17582 |
| Maximum: | 42.1979 |
| Units: | decimal degrees |
| Range of values | |
|---|---|
| Minimum: | -70.27053 |
| Maximum: | -70.20766 |
| Units: | decimal degrees |
| Range of values | |
|---|---|
| Minimum: | 42.17569 |
| Maximum: | 42.19777 |
| Units: | decimal degrees |
| Range of values | |
|---|---|
| Minimum: | -70.27048 |
| Maximum: | -70.20785 |
| Units: | decimal degrees |
| Range of values | |
|---|---|
| Minimum: | 42.17582 |
| Maximum: | 42.1979 |
| Units: | decimal degrees |
| Range of values | |
|---|---|
| Minimum: | -70.27053 |
| Maximum: | -70.20766 |
| Units: | decimal degrees |
| Range of values | |
|---|---|
| Minimum: | 42.17582 |
| Maximum: | 42.19766 |
| Units: | decimal degrees |
| Range of values | |
|---|---|
| Minimum: | -70.27053 |
| Maximum: | -70.20851 |
| Units: | decimal degrees |
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.
As a part of the process of mapping the sea floor, the USGS developed the SEABOSS to collect samples, videos, and photographs 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 were opened by collapsing the extended arms to a near-horizontal position and locked in place with two catches. The sampler operates passively to sample the seabed; it is not spring loaded.
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 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 and discarded, after which the sampler was washed in preparation for sampling at the next site. 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.
Video methods and data availability:
Seabed videos were collected using two battery-operated, high-definition (1920 x 1080 pixels) GoPro Hero 4 Black digital video cameras mounted on the SEABOSS. The SEABOSS also had a SeaViewer 6000 HD Sea-Drop, high-definition (1920 x 720 pixels), video camera attached to it with a live feed to the surface. The SeaViewer camera was mounted a little higher on the frame and was used to observe obstacles, like gill nets and lobster gear, in order to avoid entanglement. In case of camera failure, the additional 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 video lights. Each light provided a light flux of up to 9000 lumens at a correlated color temperature of 5000 kelvin. Two parallel red lasers mounted 20 centimeters apart provided a scale in the video images.
Video imagery includes the launch and recovery of the SEABOSS, transit through the water column, and the drift over the seabed. The duration of 19 individual video files ranges from 3.3 to 5.6 minutes. Video files are archived in .MP4 format and range in size from 0.8 to 1.3 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 log book at the time of the deployment of the SEABOSS, when it reached the seabed, when a grab sample was attempted, and when it left the seabed. 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. 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). 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. Person who carried out this activity:
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Are there legal restrictions on access or use of the data?Access_Constraints: None.
Use_Constraints: Not to be used for navigation.
Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
| Data format: | The ZIP file contains the station summary information in XLSX, CSV, and shapefile format, along with the browse graphic and FGDC CSDGM metadata. in format XLSX (version Microsoft Excel O365) Size: 1 |
|---|---|
| Network links: |
https://cmgds.marine.usgs.gov/data/field-activity-data/2016-004-FA/data/samples/2016-004-FA_station_summary.zip https://cmgds.marine.usgs.gov/data/field-activity-data/2016-004-FA/ https://doi.org/10.5066/P934L7PN |
| Data format: | The ZIP file contains the station summary information in XLSX, CSV, and shapefile format, along with the browse graphic and FGDC CSDGM metadata. in format CSV (version comma-separated values exported from Microsoft Excel O365) Size: 1 |
|---|---|
| Network links: |
https://cmgds.marine.usgs.gov/data/field-activity-data/2016-004-FA/data/samples/2016-004-FA_station_summary.zip https://cmgds.marine.usgs.gov/data/field-activity-data/2016-004-FA/ https://doi.org/10.5066/P934L7PN |
| Data format: | The ZIP file contains the station summary information in XLSX, CSV, and shapefile format, along with the browse graphic and FGDC CSDGM metadata. in format Shapefile (version ArcGIS 10.6.1) Size: 1 |
|---|---|
| Network links: |
https://cmgds.marine.usgs.gov/data/field-activity-data/2016-004-FA/data/samples/2016-004-FA_station_summary.zip https://cmgds.marine.usgs.gov/data/field-activity-data/2016-004-FA/ https://doi.org/10.5066/P934L7PN |
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.
