U.S. Geological Survey
2020
Sound velocity profiles - locations, images, and text files for sound velocity profiles calculated from XBT and CTD casts conducted during USGS field activities 2017-001-FA and 2017-002 FA.
1.0
digital data
data release
DOI:10.5066/P9Y1MSTN
Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.5066/P9Y1MSTN
https://www.sciencebase.gov/catalog/item/5e1e05d7e4b0ecf25c610cc2
Wayne E. Baldwin
Eric M. Moore
Charles R. Worley
Alex R. Nichols
Carolyn D. Ruppel
2020
Marine Geophysical Data Collected to Support Methane Seep Research Along the U.S. Atlantic Continental Shelf Break and Upper Continental Slope Between the Baltimore and Keller Canyons During U.S. Geological Survey Field Activities 2017-001-FA and 2017-002-FA.
1.0
data release
DOI:10.5066/P9Y1MSTN
Reston, VA
U.S. Geological Survey
Suggested citation: Baldwin, W.E., Moore, E.M., Worley, C.R., Nichols, A.R., and Ruppel, C.D., 2020, Marine Geophysical Data Collected to Support Methane Seep Research Along the U.S. Atlantic Continental Shelf Break and Upper Continental Slope Between the Baltimore and Keller Canyons During U.S. Geological Survey Field Activities 2017-001-FA and 2017-002-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P9Y1MSTN.
https://doi.org/10.5066/P9Y1MSTN
https://www.sciencebase.gov/catalog/item/5e179176e4b0ecf25c59f97a
In spring and summer 2017, the U.S. Geological Survey’s Gas Hydrates Project conducted two cruises aboard the research vessel Hugh R. Sharp to explore the geology, chemistry, ecology, physics, and oceanography of sea-floor methane seeps and water column gas plumes on the northern U.S. Atlantic margin between the Baltimore and Keller Canyons. Split-beam and multibeam echo sounders and a chirp subbottom profiler were deployed during the cruises to map water column backscatter, sea-floor bathymetry and backscatter, and subsurface stratigraphy associated with known and undiscovered sea-floor methane seeps. The first cruise, known as the Interagency Mission for Methane Research on Seafloor Seeps and designated as field activity 2017-001-FA, was conducted from May 4 to May 11, 2017, and acquired geophysical data to support remotely operated vehicle exploration of seep sites using the Global Explorer, which is operated by Oceaneering International, Inc. Geophysical operations during cruise 2017-002-FA from August 25 to September 6, 2017, were also focused on mapping water column methane plumes, sea-floor seep sites, and subseafloor strata, but primarily supported conductivity, temperature, and depth instrument deployment, surface-water methane-concentration mapping, and water-sampling operations as part of a collaborative study with the University of Rochester of the effect of methane seepage on ocean water biogeochemistry. The National Oceanic and Atmospheric Administration’s Office of Ocean Exploration and Research partially sponsored cruise 2017-001-FA, and the U.S. Department of Energy partially sponsored both cruises.
This dataset is used to display the locations of sound velocity profiles (SVP, also referred to as sound speed profiles), as well as the SVP data, collected using Sippican XBT probes and a Seabird Electronics 911plus CTD during two 2017 USGS cruises along the U.S. Atlantic continental shelf break and upper continental slope between Accomac and Keller Canyons. The sound velocity profiles document water column sound speed variability during the cruises, and were used during processing to account for refraction artifacts present within the multibeam bathymetric data. The dataset contains graphs of the sound velocity profile at each station, as well as the date of collection, time of day, and station location coordinates in Geographic Coordinate System (GCS) WGS 84 latitude and longitude.
Support for 2017-001-FA was provided to the USGS by NOAA and DOE through interagency agreements 16-01118 and DE-FE0023495, respectively. Support for 2017-002-FA was provided to the USGS and the University of Rochester by DOE through interagency agreement DE-FE0026195 and grant DE-FE0028980, respectively. Additional information on the field activities are available from https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-001-FA and https://cmgds.marine.usgs.gov/fan_info.php?fan=2017-002-FA. Additional information specific to the Interagency Mission for Methane Research on Seafloor Seeps is available at https://www.usgs.gov/centers/whcmsc/science/immerss-interagency-mission-methane-research-seafloor-seeps?qt-science_center_objects=0#qt-science_center_objects and https://archive.usgs.gov/archive/sites/soundwaves.usgs.gov/2017/05/outreach.html.
20170504
20170905
ground condition
None planned.
-75.777222
-74.070000
37.813333
35.296667
USGS Metadata Identifier
USGS:5e1e05d7e4b0ecf25c610cc2
None
U.S. Geological Survey
USGS
Woods Hole Coastal and Marine Science Center
WHCMSC
Coastal and Marine Hazards and Resources Program
CMHRP
Department of the Interior
DOI
National Oceanic and Atmospheric Administration - Office of Ocean Exploration and Research
NOAA-OER
Department of Energy
DOE
University of Rochester
field activity number 2017-001-FA
HRS1704
Interagency Mission for Methane Research on Seafloor Seeps
IMMeRSS
field activity number 2017-002-FA
HRS1713
R/V Hugh R. Sharp
shapefile
Sippican XBT
Seabird Electronics 911plus CTD
SVP
SSP
PNG
sound velocity profile
sound speed profile
marine geophysics
oceanography
ISO 19115 Topic Category
oceans
geoscientificInformation
location
USGS Thesaurus
profiles
sound velocity
ocean sciences
navigational data
None
United States of America
Atlantic Ocean
Atlantic Margin
Accomac Canyon
Washington Canyon
Norfolk Canyon
Keller Canyon
Chincoteague Ridge
none
2017
none
Public domain data from the U.S. Government are freely distributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
Wayne E. Baldwin
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Road
Woods Hole
Massachusetts
02543-1598
USA
508-548-8700 x2226
508-457-2310
wbaldwin@usgs.gov
https://www.sciencebase.gov/catalog/file/get/5e1e05d7e4b0ecf25c610cc2/?name=2017-001-FA_2017-002-FA_SVPdata_browse.jpg
Example SVP profile image.
JPG
Demopoulos, A.
McClain-Counts, J.
Bourque, J.
Prouty, N.
Smith, B.
Brooke, S.
Ross, S.
Ruppel, C.
2019
Examination of Bathymodiolus childressi nutritional sources, isotopic niches, and food-web linkages at two seeps in the US Atlantic margin using stable isotope analysis and mixing models.
1.0
document
Deep Sea Research Part I
148, pp.53-66
Amsterdam, Netherlands
Elsevier
https://doi.org/10.1016/j.dsr.2019.04.002
Leonte, M.
Ruppel, C. D.
Ruiz‐Angulo, A.
Kessler, J. D.
2020
Surface methane concentrations along the Mid‐Atlantic Bight driven by aerobic subsurface production rather than seafloor gas seeps.
1.0
document
Journal of Geophysical Research: Oceans
vol. 125
Washington, DC
American Geophysical Union Publications
https://doi.org/10.1029/2019JC015989
Leonte, M.
Ruppel, C. D.
Ruiz‐Angulo, A.
Kessler, J. D.
2020
Water temperature, salinity, methane, methane stable isotopes, and others chemical parameters collected by CTD and Niskin bottles from research vessel Hugh R. Sharp in Mid-Atlantic Bight from 2017-08-25 to 2017-09-05.
1.0
dataset
NOAA National Centers for Environmental Information Dataset
NCEI Accession 0209090
Boulder, CO
NOAA National Centers for Environmental Information
https://doi.org/10.25921/pr39-4f13
Ruppel, C.
Demopoulos, A.
Prouty, N.
2018
Exploring US Mid-Atlantic Margin Methane Seeps: IMMeRSS, May 2017.
1.0
document
Supplement to Oceanography
31(1), p.93
Rockville, MD
The Oceanography Society
https://doi.org/10.5670/oceanog.2018.supplement.01
Sound velocity profiles were calculated from either Sippican Expendable Bathythermograph (XBT, T4 or T5 types) probe temperature and depth data or Seabird Electronics (SBE) 911plus conductivity, temperature, and depth (CTD) cast data. XBT probes were primarily launched during overnight geophysical mapping operations on both cruises, while CTD casts were conducted during daytime operations on 2017-002-FA only. 2017-001-FA_T4XBT01, 2017-001-FA_T4XBT05, 2017-001-FA_T4XBT07, and 2017-002-FA_T4XBT01 do not coincide with a trackline in '2017-001-FA_2017-002-FA_7160Tracklines.shp' or '2017-001-FA_2017-002-FA_EK60Tracklines' because the casts were conducted either prior to the start of geophysical survey operations or after they were completed. The approximately 11 meter profile for cast 2017-002-FA_CTD08 represents a test deployment of the CTD system in the Delaware River estuary.
Each sound velocity profile (51 total) collected during cruises 2017-001-FA and 2017-002-FA is represented by a Caris .svp formatted ASCII text file (see description below in the entity and attribute overview section), a PNG image file, and a feature point location in '2017-001-FA_2017-002-FA_SVPdata.shp'.
Navigation for the XBT casts was provided using a Hemisphere GPS receiver. XBTs were launched from the center of the stern, ~ 16 m aft of the GPS antenna mounted on the aft 01 deck handrail and the positional offset was not accounted for. A HYPACK (v. 17.0.26.0) target was created to record the position of each SVP station, and the geographic coordinates were manually entered into the WinMK21 (version 7.1) acquisition software as casts were conducted. Navigation for the CTD casts was provided by the vessel's Furuno GP-37 GPS and logged to the raw data header. CTD operations were conducted from the CTD winch station located on the starboard side approximately amidships. While the horizontal position accuracy is thought to be within 3 meters for the GPS position solutions, we consider the positions for the XBT casts to be within approximately 20 m, since the offset to the stern launch position was not accounted for. Reported positions represent locations at the start of each cast.
XBTs depths are estimated as a function of time after deployment via fall-rate equations by the WinMK21 (version 7.1) acquisition software and derived depths are accurate to within 2 percent of the water depth. SBE 911plus CTD depths are estimated by the Seabird Seasave (version 7.26.7) acquisition software via a calculation converting pressure sensor readings to depths while taking into account sea water density and gravity as a function of latitude, and the depths are thought to be accurate to within 1 meter.
U.S. Geological Survey
unpublished material
XBT and CTD profile data
disc
20170504
20170905
ground condition
XBT and CTD profile data
A Sippican XBT system consisting of a hand launcher connected via cable to an MK21 processing unit was used to launch Sippican T4 and T5 XBT probes (maximum depths of 460 and 1830 m, respectively) from the center stern of the vessel, and WinMK21 (version 7.1) acquisition software logged the temperature and depth data during each deployment. GPS navigation data for the sound velocity profiles were acquired using the WGS 84 coordinate system with a Hemisphere GPS receiver. XBTs were launched from the center of the stern, ~ 16 m aft of the GPS antenna mounted on the aft 01 deck handrail and the positional offset was not accounted for. A HYPACK (v. 17.0.26.0) target was created to record the position of each SVP station, and the geographic coordinates were manually entered into the WinMK21 (version 7.1) acquisition software as casts were conducted. CTD data were collected using an SBE 911plus CTD system, consisting of a 9plus CTD unit deployed from the CTD winch station located on the starboard side approximately amidships, with data transferred via the winch wire through a slip ring, and logged by an 11plus deck unit and Seabird Seasave (version 7.26.7) acquisition software in real time. Navigation for the CTD casts was provided by the vessel's Furuno GP-37 DGPS and logged to the raw data header.
XBT and CTD deployment and data and processing at sea:
During 2017-001-FA and 2017-002-FA XBT probes were generally deployed at the start and end of each overnight geophysical watch and intermittently when the multibeam bathymetric data were substantially impacted by sound speed related refraction artifacts. The Raw XBT EDF files recorded by the WinMK21 (version 7.1) acquisition software were imported into SVPEditor (version 1.0.5), which calculated a sound velocity profile via the UNESCO equation (Fofonoff and Millard, 1983) using the temperature profile data and a synthetic salinity profile estimated from World Ocean Atlas (2009) data at the location of the cast. The resulting sound velocity profiles were exported in Caris .svp and HYPACK .vel formatted ASCII files. CTD casts were primarily performed during daytime operations of 2017-002-FA only. R/V Sharp technicians used Seabird Seasave (version 7.26.7) to acquire and process the raw CTD HEX data, with one of the resulting outputs being a .sv_csv sound velocity profile for the downward portion of the cast, also calculated using the UNESCO equation. A python script was used to extract the time and position for the start of the cast from the processed .csv file, and the processed depth and sound velocity columns from the .sv_csv file and save them to a Caris .svp formatted ASCII file. (Fofonoff, N.P. and Millard Jr, R.C. (1983) Algorithms for the computation of fundamental properties of seawater. Paris, France, UNESCO, 53pp. (UNESCO Technical Papers in Marine Sciences; 44), http://hdl.handle.net/11329/109)
This process step and all subsequent process steps were conducted by the same person - Wayne Baldwin.
201709
Wayne E. Baldwin
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2226
(508) 457-2310
wbaldwin@usgs.gov
Plot the SVP data and import into SpatiaLite database:
A python script was used to read the SVP data and plot the sound speed profile as speed of sound (meter/second) versus depth (meters). Position, date, and time were pulled from the SVP header and written into the image (PNG) for reference. Within the same script, the position, Julian day, time, and profile id were also imported into a SpatiaLite (version 4.3.0) enabled SQLite (version 3.26.0) database table. The geographic positions were used to create point geometries for the station locations, and additional fields indicating Survey_ID, Vessel_ID, Device_ID, and SVP_Image were added.
201910
Create Esri shapefile containing the point data:
The SVP point features were added (Add Data) into ArcMap (version 10.7.1) from the SQLite database, then exported (Right click on database feature class > Data > Export Data) to the new Esri point shapefile '2017-001-FA_2017-002-0FA_SVPdata.shp'.
201910
Added keywords section with USGS persistent identifier as theme keyword.
20200806
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
0.000001
0.000001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.257224
2017-001-FA_2017-002-FA_SVPdata.shp
Sound velocity profile location shapefile for surveys 2017-001-FA and 2017-002-FA (51 point features).
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.
Lon
Decimal degree longitude value in GCS WGS 84.
U.S. Geological Survey
-75.777222
-74.07
degrees
.000001
Lat
Decimal degree latitude value in GCS WGS 84.
U.S. Geological Survey
35.296667
37.813333
degrees
.000001
SVP
Name of sound velocity profile used to distinguish between casts. Profile names containing 'XBT' refer to the Sippican XBT casts, and those containing 'CTD' refer to Seabird Electronics 911plus CTD casts (in names for XBT casts, the probe type is prepended to 'XBT'; the last two digits in each XBT and CTD casts indicates sequential cast number.)
U.S. Geological Survey
character set
Date
mm/dd/yyyy when the SVP cast was collected.
U.S. Geological Survey
character set
JD_UTC
Julian day and UTC time when the SVP cast was collected in the format: JD:HH:MM:SS; Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection.
U.S. Geological Survey
character set
SurveyID
WHMSC field activity identifier (e.g. "2017-001-FA" where 2017 is the survey year, 001 is survey number of that year, and FA is field activity).
U.S. Geological Survey
character set
VehicleID
Survey vessel name.
U.S. Geological Survey
character set
DeviceID
Device used to collect sound speed profile data.
U.S. Geological Survey
character set
SVP_Image
Name of the PNG image file associated with the SVP cast.
U.S. Geological Survey
Character set
2017-001-FA_2017-002-FA_SVP_ASCII
Sound velocity profile data in Caris SVP (.svp) ASCII format for surveys 2017-001-FA and 2017-002-FA (51 SVP files)
U.S. Geological Survey
2017-001-FA_2017-002-FA_SVP_Images
Portable network graphic images of sound velocity profile data for surveys 2017-001-FA and 2017-002-FA (51 PNG files)
U.S. Geological Survey
The PNG images can be hyperlinked to their shapefile location in ArcGIS. The graphs show depth on the y-axis and speed of sound on the x-axis. In addition to the graphs, the SVP data is also available in Caris .svp formatted ASCII files. The format of the .svp files is as follows:
Header row1: [SVP_VERSION_2] (format version number)
Header row2: 2017-001-FA_T4XBT01.svp (cast file name)
Header row3: Section 2017-237 23:42:54 37:31:48 -74:18:36 (Caris Section header indicating Year-Day, UTC Time, Degree:Minute:Second Latitude, and Degree:Minute:Second Longitude of cast)
Remaining rows: column data of depth (meters) and speed of sound (meters per second) space delimited.
U.S. Geological Survey
U.S. Geological Survey - ScienceBase
mailing and physical address
Federal Center
Building 810
Mail Stop 302
Denver
CO
80225
1-888-275-8747
USGS data release of sound velocity profiles collected along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during USGS field activities 2017-001-FA and 2017-002-FA: includes the shapefile '2017-001-FA_2017-002-FA_SVPdata.shp', the zip archive '2017-001-FA_2017-002-FA_SVP_Images.zip' containing 51 PNG images that represent all sound velocity profiles graphically, the zip archive '2017-001-FA_2017-002-FA_SVP_ASCII.zip' containing 51 Caris .svp formatted ASCII files, the browse graphic '2017-001-FA_2017-002-FA_SVPdata_browse.jpg', and the Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file '2017-001-FA_2017-002-FA_SVPdata_meta.xml'.
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.
Shapefile
ArcMap 10.7.1
shapefile
Shapefile of SVP profile locations collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during USGS field activities 2017-001-FA and 2017-002-FA.
none
0.085
https://www.sciencebase.gov/catalog/item/5e1e05d7e4b0ecf25c610cc2
https://www.sciencebase.gov/catalog/file/get/5e1e05d7e4b0ecf25c610cc2
https://doi.org/10.5066/P9Y1MSTN
The first link is to the page containing the data. The second is a direct link to download all data available from the page as a zip file. The final link is to the publication landing page. The data page (first link) may have additional data access options, including web services.
TEXT
0.24
Caris .svp ASCII text file
Zip compressed folder containing Caris .svp formatted text files of sound speed profile data collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during USGS field activities 2017-001-FA and 2017-002-FA..
any zip utility
1
https://www.sciencebase.gov/catalog/item/5e1e05d7e4b0ecf25c610cc2
https://www.sciencebase.gov/catalog/file/get/5e1e05d7e4b0ecf25c610cc2
https://doi.org/10.5066/P9Y1MSTN
The first link is to the page containing the data, the second link downloads all data available from the page as a zip file, and the third link is to the publication landing page.
PNG
Matplotlib (version 2.0.0)
portable network graphic (PNG)
Zip compressed folder containing images of the sound speed profiles collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center along the U.S. Atlantic continental shelf break and upper slope between Accomac and Keller Canyons during USGS field activities 2017-001-FA and 2017-002-FA..
any zip utility
2.87
https://www.sciencebase.gov/catalog/item/5e1e05d7e4b0ecf25c610cc2
https://www.sciencebase.gov/catalog/file/get/5e1e05d7e4b0ecf25c610cc2
https://doi.org/10.5066/P9Y1MSTN
The first link is to the page containing the data, the second link downloads all data available from the page as a zip file, and the third link is to the publication landing page.
none
To utilize these data, the user must have software capable of reading shapefiles, ASCII text, and/or PNG images.
20200806
Wayne E. Baldwin
U.S. Geological Survey
Geologist
mailing and physical address
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2226
(508) 457-2310
wbaldwin@usgs.gov
fgdc content standards for digital geospatial metadata
FGDC-STD-001-1998
local time