John F. Bratton
VeeAnn A. Cross
2012
Processed continuous resistivity profile data collected by the U.S. Geological Survey in Great South Bay on Long Island, New York, on Sept. 25, 2008
1
Open-File Report
2011-1040
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.3133/ofr20111040
https://pubs.usgs.gov/of/2011/1040/html/catalog.html
https://pubs.usgs.gov/of/2011/1040/data/resistivity/proc_resis/sept25_proc.zip
V.A. Cross
J.F. Bratton
K.D. Kroeger
J. Crusius
C.R. Worley
2012
Continuous Resistivity Profiling Data from Great South Bay, Long Island, New York
1
Open-File Report
2011-1040
Reston, VA
U.S. Geological Survey
1 DVD
https://pubs.usgs.gov/of/2011/1040/
An investigation of submarine aquifers adjacent to the Fire Island National Seashore and Long Island, New York, was conducted to assess the importance of submarine groundwater discharge (SGD) as a potential nonpoint source of nitrogen delivery to Great South Bay. More than 200 kilometers (km) of continuous resistivity profiling (CRP) data were collected to image the fresh-saline groundwater interface in sediments beneath the bay. In addition, groundwater sampling was performed at sites (1) along the northern shore of Great South Bay, particularly in Patchogue Bay, that were representative of the developed Long Island shoreline, and (2) at sites on and adjacent to Fire Island, a 50-km-long barrier island on the southern side of Great South Bay. Other field activities included sediment coring, stationary electrical resistivity profiling, and surveys of in-situ pore water conductivity. The onshore and offshore shallow hydrostratigraphy of the Great South Bay shorelines, particularly the presence and nature of submarine confining units, appears to exert primary control on the dimensions and chemistry of the submarine groundwater flow and discharge zones. Sediment coring has shown that the confining units commonly consist of drowned and buried peat layers likely deposited in salt marshes. Based on CRP data, low-salinity groundwater extends from 10 to 100 meters (m) offshore along much of the northern and southern shores of Great South Bay, especially off the mouths of tidal creeks, and beneath shallow flats to the north of Fire Island adjacent to modern salt marshes. Human modifications of much of the shoreline and nearshore areas along the northern shore of the bay, including filling of salt marshes, construction of bulkheads and piers, and dredging of navigation channels, has substantially altered the natural hydrogeology of the bay's shorelines by truncating confining units and increasing recharge near the shore in filled areas. Better understanding of the nature of SGD along developed and undeveloped shorelines of embayments such as this could lead to improved models and mitigation strategies for nutrient overenrichment of estuaries. For more information on the surveys involved in this project, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2008-007-FA and https://cmgds.marine.usgs.gov/fan_info.php?fan=2008-037-FA.
This dataset provides the processed continuous resistivity profile (CRP) data collected on Sept. 25, 2008 in Great South Bay on Long Island, New York. The CRP system (AGI SuperSting) images the subsurface electrical properties of an estuarine, riverine or lacustrine environment. Resistivity differences can be attributed to subsurface geology (conductive vs less conductive layers) and hydrogeologic conditions with fresh water exhibiting high resistivity and saline conditions showing low resistivity. This also acts as an archive of these data.
20080925
ground condition
None planned
-73.212600
-73.172167
40.709333
40.697050
USGS Metadata Identifier
USGS:d3758f26-95a9-4091-85d8-6aadbb927e2c
None
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Woods Hole Coastal and Marine Science Center
WHCMSC
Field Activity Number 2008-037-FA
Info Bank ID T-37-08-LI
navigation
bathymetry
Continuous Resistivity Profiling
CRP
Lowrance GPS
AGI SuperSting
processed data
groundwater
submarine groundwater
R/V Terrapin
ISO 19115 Topic Category
elevation
location
oceans
geoscientificInformation
USGS Thesaurus
continuous resistivity profiling
image collections
navigational data
None
North America
North Atlantic
United States
New York
Long Island
Great South Bay
Fire Island
Suffolk County
None.
The public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
Woods Hole Coastal and Marine Science Center
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
vatnipp@usgs.gov
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.4000
Advanced Geosciences, Inc.
2008
Instruction Manual for EarthImager 2D, version 2.2.8, Resistivity and IP inversion software
Austin, Texas
Advanced Geosciences, Inc.
http://www.agiusa.com
Advanced Geosciences, Inc.
2003
Instruction Manual for the Marine Log Manager Module of the Administrator for SuperSting Software, Release 1.3.7
Austin, Texas
Advanced Geosciences, Inc.
http://www.agiusa.com
All data collected on this day were collected with the 15-m streamer.
All usable data collected on this day was processed. File L74F1 did not have an STG file, so could not be processed.
The navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located at the anchor point for the resistivity streamer, which is also directly above the fathometer transducer mount point. The GPS system is published to be accurate to within 10 meters.
All collected bathymetry values were collected by the 200 kHz Lowrance fathometer. The fathometer was mounted starboard side aft, directly below the GPS antenna and the resistivity streamer tow point. The transducer was approximately 0.30 meters below the sea surface, and this draft was not corrected for. The Lowrance manufacturer indicates the speed of sound used by the system to convert to depths is 4800 feet/second. All values are assumed to be accurate to within 1 meter.
The continuous resistivity profile (CRP) system used on this cruise was an AGI SuperSting marine system described at the website: www.agiusa.com/marinesystem.shtml. Two different streamers were used for data collection - not simultaneously. One streamer was a 50-m streamer with an 11 electrode array with electrodes spaced 5 meters apart. The other streamer was a 15-m streamer with an 11 electrode array with electrodes spaced 1.5 meters apart. In both cases, the source electrodes are graphite, while the receiver electrodes are stainless steel. A dipole-dipole configuration was used for the data collection in which two fixed current electrodes are assigned with the measurement of voltage potential between electrode pairs in the remaining electrodes. The maximum depth below the water surface the streamer can reach is approximately ΒΌ the streamer length. So for the 50-m streamer, maximum depth is about 12.5 meters, while the 15 meter streamer can reach about 3.75 meters. Each line of data acquisition records several files. The two files necessary for processing are the *.stg and the *.gps file. The STG file contains the resistivity data, while the GPS file contains the navigation information. The navigation system used in concert with the CRP system is a Lowrance LMS-480M with an LGC-2000 GPS antenna and a 200 kHz fathometer transducer. The transducer also contains a temperature sensor. Lowrance indicates the speed of sound used by the system is 4800 feet/second. Both the temperature and depth information are recorded in the logged GPS file. The CRP system images the subsurface electrical properties of an estuarine, riverine or lacustrine environment. Resistivity differences can be attributed to subsurface geology (conductive vs less conductive layers) and hydrogeologic conditions with fresh water exhibiting high resistivity and saline conditions showing low resistivity.
2008
The resistivity data (*.stg) were merged with the navigation data (*.gps) and linearized using AGI's Marine Log Manager software. (Note that the Marine Log Manager version is different than the software version of the AGISSAdmin software of which it is a part - although shipped together, the software is developed separately). The version of Marine Log Manager used was AGI SSAdmin MLM v 1.3.4.217. The GPS offset in MLM was set to +2 because an offset value of 0 was used during data acquisition, yet the offset from the GPS antenna to the first electrode was 2 meters. The output from this process is a linearized STG file and a DEP file which contains water depths at distances along line. This process step and all subsequent process steps were performed by the same person - VeeAnn A. Cross.
*.stg
*.gps
200809
*lin.stg
*.dep
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
Woods Hole Coastal and Marine Science Center
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
vatnipp@usgs.gov
Initial processing of L70F1 and L72F1 indicated anomalies in the water column. In an attempt to fix this, L70F1.stg was copied to L70F1_mod.stg and removed the electrode measurements at 13:51:45. For L72F1, after the linearization, copied L72F1_lin.stg to L72F1_linmod.stg and used VI to remove the last electrodes set which was causing a water column anomaly.
*.stg
200810
*mod.stg
Each DEP file was checked for anomalous bathymetry values, or duplicated distance along values, and those lines in the file were deleted.
200810
EarthImager software does not require that a default resistivity value for the water column be supplied in the DEP file. If one is not supplied, then it calculates a value based on the first electrode pair. For this cruise salinity was measured on a water sample taken from the bay. The salinity was measured at 25 ppt. Using an average water temperature of 19.45 degrees Celsius, a resistivity value of 0.29 ohm-m was calculated to use for the data processing. This calculation was done using the website <http://www2.sese.uwa.edu.au/~hollings/pilot/denscalc.html> and using the 1/conductivity for the result. The water resistivity value was added to the appropriate place in the DEP files so that a known water resistivity value would be used in the calculations. As of 2012, the website for the density calculation has changed: http://fermi.jhuapl.edu/denscalc.html.
*.dep
200810
*wres.dep
EarthImager version 2.2.8 build 562 was then used to process the data files. The *.ini file accompanying the results contains the parameters used during the processing. These parameters include: minimum voltage: 0.02; minimum abs(V/I): 2E-5; max repeat error: 3%; min apparent res: 0.03; max apparent res: 1000; max reciprocal error: 5%; remove negative resistivity, smooth model inversion; finite element method; Cholesky decomposition; Dirichlet boundary condition; thickness incremental factor: 1.1; depth factor: 1.1; max number of CG iterations: 100; stop criteria: number of iterations 8; max RMS 3%; error reduction 5%; L2Norm; CRP processing using a 65% overlap. These INI files can be loaded in EarthImager to help maintain consistent processing parameters for other datasets. When the files are processed, numerous files are generated. Because of the "roll-along" nature of the processing, each line takes several iterations of processing which are then combined into a single output. The output consists of numerous files including JPEG images and text files representing the XYZ position of each resistivity value. The output consists of numerous files including JPEG images and text files representing the XYZ position of each resistivity value. There are two JPEG image generated with each process when possible - a long version with the x-axis labeled with latitude and longitude values and a corresponding short version of the same information. The JPEG files produced use a color scale for the resistivity that is based on the data extent from that particular file. The JPEG images also include a plot of temperature along the line. In addition to the JPEG images, there are text files with the extensions of *.llt, and *.xyz. Each of these is a text file. The LLT file has four columns of information: longitude in decimal degrees, latitude in decimal degrees, depth in meters, and resistivity value in ohm-m. The XYZ file has three columns of information: distance along line in meters, depth in meters, and resistivity value in ohm-m. You can process an individual line as many times as you want and the software places the results in incrementing folder names starting with trial1. These data represent in most cases trial2, which is the processing with the water resistivity value. The exception to this is L72F1 which was modified after linearization and only has 1 trial - and that with the water resistivity value. Because one of the files collected on this day is so short, the roll-along component of the processing was unnecessary. For this reason, the JPEG image and the XYZ data had to be saved manually. First, just the inverted resistivity line is displayed using View - Inverted Resistivity Section. Then the image can be saved using File - Save Image. And finally, the XYZ data had to be saved manually using File - Save Data in XYZ format. The XYZ output file extension is DAT instead of XYZ. This DAT file three columns of information: distance along line in meters, depth in meters, and resistivity value in ohm-m. Automatically generated is the file with the LLT extension. The LLT file has four columns of information: longitude in decimal degrees, latitude in decimal degrees, depth in meters, and resistivity value in ohm-m. This shorter data file also represents trial2 which is the processing with the water resistivity value. The white line appearing in most of the JPEG images is the seafloor position based on the bathymetry.
*lin.stg
*wres.dep
200810
*.ini
*.llt
*.xyz or *.dat
*.jpg
The XYZ output file was then loaded into MATLAB version 7.5.0.342 (R2007b), along with the depth information from the DEP file, to create a new JPEG image with the same color scale for all the data files. In this manner, the JPEG images can be compared directly. Care was taken to try to get the vertical and horizontal scales uniform as well, although this was not always possible due to MATLAB limitations. These images reside in the "matlabimages" folder. These JPEG images include a black line within the resistivity profile which represents the sediment water interface based on the depth values from the DEP file. The local MATLAB script used to load the 15-m streamer data was cp_gsbay_15m.m. The local MATLAB script used to export the JPEG image was exportfig.m.
*.xyz or *.dat
*wres.dep
201010
*.jpg
Corel PhotoPaint v. 11 was used to crop excess white space from around the MATLAB resistivity profile JPEG images, saving the JPEGs with the same filename.
*.jpg
201010
*.jpg
Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Attempted to modify http to https where appropriate. Updated the link to the field activity. Moved the minimal source information provided to make it the first process step. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. Added a distribution format to account for the JPEG images in the zip file. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent.
20171006
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
USGS Thesaurus keywords added to the keyword section.
20180720
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
Crossref DOI link was added as the first link in the metadata.
20191118
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
Added keywords section with USGS persistent identifier as theme keyword.
20200908
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
Local surface
0.1
meters
Explicit depth coordinate included with horizontal coordinates
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
Woods Hole Coastal and Marine Science Center
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
vatnipp@usgs.gov
Downloadable Data
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.
TEXT
The WinZip (version 9.0) file contains all the processed CRP data from Sept. 23, 2008 as well as the associated metadata files.
7.9
https://pubs.usgs.gov/of/2011/1040/data/resistivity/proc_resis/sept25_proc.zip
https://pubs.usgs.gov/of/2011/1040/html/catalog.html
JPEG
The WinZip (version 9.0) file contains all the processed CRP data from Sept. 23, 2008 as well as the associated metadata files.
7.9
https://pubs.usgs.gov/of/2011/1040/data/resistivity/proc_resis/sept25_proc.zip
https://pubs.usgs.gov/of/2011/1040/html/catalog.html
None.
The data are provided in a WinZip compressed file. The user must have software capable of uncompressing the archive. In addition, portions of the processed data are available in a format compatible with AGI Geosciences EarthImager software. The user must have software capable of reading the AGI format in order to process these data. The data are also available in an XYZ ASCII format.
20240318
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
mailing and physical address
Woods Hole Coastal and Marine Science Center
384 Woods Hole Rd.
Woods Hole
MA
02543-1598
(508) 548-8700 x2251
(508) 457-2310
whsc_data_contact@usgs.gov
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318)
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
local time