VeeAnn A. Cross
2014
Point shapefile of processed continuous resistivity profiling data below the sediment water interface collected in the Indian River Bay, Delaware, on April 14, 2010, on U.S. Geological Survey Field Activity 2010-006-FA (MRGAPR14_ALLXYZRES.SHP, Geographic, WGS 84)
1
vector digital data
Open-File Report
2011-1039
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Geology Program
https://doi.org/10.3133/ofr20111039
https://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html
https://pubs.usgs.gov/of/2011/1039/data/resistivity/shapefile/mrgapr14_allxyzres.zip
V.A. Cross
J.F. Bratton
H.A. Michael
K.D. Kroeger
A. Green
E. Bergeron
2014
Continuous Resistivity Profiling and Seismic-Reflection Data Collected in April 2010 from Indian River Bay, Delaware
1
Open-File Report
2011-1039
Reston, VA
U.S. Geological Survey
https://pubs.usgs.gov/of/2011/1039/
https://doi.org/10.3133/ofr20111039
A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was carried out in April 2010. This included surveying at higher spatial resolution in the vicinity of a study site at Holts Landing, where intensive onshore and offshore studies were subsequently completed. The total length of continuous resistivity profiling (CRP) survey lines was 145 kilometers (km), with 36 km of chirp seismic lines surveyed around the perimeter of the bay. Medium-resolution CRP surveying was performed using a 50-meter streamer in a bay-wide grid. Results of the surveying and data inversion showed the presence of many buried paleochannels beneath Indian River Bay that generally extended perpendicular from the shoreline in areas of modern tributaries, tidal creeks, and marshes. An especially wide and deep paleochannel system was imaged in the southeastern part of the bay near White Creek. Many paleochannels also had high-resistivity anomalies corresponding to low-salinity groundwater plumes associated with them, likely due to the presence of fine-grained estuarine mud and peats in the channel fills that act as submarine confining units. Where present, these units allow plumes of low-salinity groundwater that was recharged onshore to move beyond the shoreline, creating a complex fresh-saline groundwater interface in the subsurface. The properties of this interface are important considerations in construction of accurate coastal groundwater flow models. These models are required to help predict how nutrient-rich groundwater, recharged in agricultural watersheds such as this one, makes its way into coastal bays and impacts surface water quality and estuarine ecosystems. For more information on the survey conducted for this project, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2010-006-FA.
The purpose of this shapefile is to release all the processed continuous resistivity profile data that occurs at the sediment water interface or below collected in the Indian River Bay on April 14, 2010. These data were processed with a single water resistivity value.
20100414
ground condition
None planned
-75.194306
-75.074833
38.615210
38.571023
USGS Metadata Identifier
USGS:80522d48-b8a7-4b93-834d-12fdf23f6a34
None
U.S. Geological Survey
USGS
Coastal and Marine Geology Program
CMGP
Woods Hole Coastal and Marine Science Center
WHCMSC
Field Activity Number 2010-006-FA
Info Bank ID K-6-10-DL
navigation
bathymetry
Continuous Resistivity Profiling
CRP
R/V Knob
Lowrance GPS
AGI SuperSting
processed data
groundwater
submarine groundwater
point shapefile
Open-file Report 2011-1039
ISO 19115 Topic Category
elevation
location
oceans
geoscientificInformation
USGS Thesaurus
continuous resistivity profiling
geospatial datasets
None
North America
North Atlantic Ocean
United States
Delaware
Indian River Bay
Indian River Inlet
Holts Landing
Piney Neck
Sussex County
Rosedale Beach
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
https://pubs.usgs.gov/of/2011/1039/data/resistivity/shapefile/mrgapr14_allxyzres.gif
Thumbnail GIF image showing the location of the processed CRP data in Indian River Bay collected on April 14, 2010. The coastline is included for spatial reference.
GIF
Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4095
All the data files were checked and handled in the same manner.
All of the CRP data processed with a single water resistivity value from April 14, 2010 are incorporated into this shapefile.
The navigation system used was a Lowrance 480M with an LGC-2000 Global Positioning System (GPS) antenna. The antenna was located directly above the fathometer transducer mount point, and approximately 2 meters starboard of the mount point of the towed continuous resistivity profile streamer. GPS data are assumed to be accurate wtihin 10 meters on this survey.
All bathymetry values were acquired by the 200 kHz Lowrance fathometer. The fathometer was mounted on the starboard side of the R/V Knob, directly below the GPS antenna. The Lowrance manufacturer indicates the speed of sound used by the system to calculate to depth is 4800 feet/second. The depth values are not corrected for the approximately 0.2 m transducer draft. All values are assumed to be accurate to within 1 meter. Some of the depths recorded as attributes are extracted from a gridded surface and are assumed to be accurate 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. The particular system used for this acquisition was a 50-m streamer with an 11 electrode array with electrodes spaced 5 meters apart. 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 1/4 the streamer length. So for the 50-m streamer, maximum depth is about 12.5 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 antenna and fathometer transducer were mounted on the starboard side of the boat. The streamer tow point was on the port side aft. The layback offset between the navigation antenna and the first electrode was 17.6 meters on April 13 and 14. On April 15 the antenna and transducer were moved 1.6 m aft changing the layback offset to 16 m. This layback offset is accounted for by the acquisition system. The approximately 2 m lateral offset is not accounted for. The Lowrance 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. There are instances where no depth or temperature information is recorded due to an equipment problem. 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.
2010
One of the resulting files from processing resistivity data with AGI's EarthImager software is an XYZ file. This XYZ file has three columns of information: distance along line (meters), resistivity reading depth (meters), resistivity value (ohm-m). One of the resulting files from linearization of the raw STG resistivity data is a DEP file. The DEP file has four columns of information: distance along line (meters), water depth (meters), latitude, longitude. This DEP file is dependent on the presence of bathymetry data in the originally recorded GPS file, or the addition of bathymetry information to that GPS file. This DEP file is used in the EarthImager processing and is carried over to the processing output. The MATLAB script justbelowsed.m combines these two data files such that the output is only the resistivity values that fall at or below the sediment water interface. This script was written by the USGS in Woods Hole. In order to have a value at the sediment water interface, the software usually has to interpolate values. The version of MATLAB used for these data was MATLAB 7.5.0.342 (R2007b). An example of the script usage in MATLAB is: justbelowsed('L10F1_lin_AllInvRes.xyz','L10F1_lin_wres.dep'). The output is: L10F1_lin_AllInvRes_jbsed.xyz. This resulting XYZ file has 5 columns of information: distance along line (meters); depth below water surface (meters); depth below sediment/water interface (meters); resistivity value (ohm-m); log(10) resistivity value. This process step and all subsequent process steps were performed by the same person - VeeAnn A. Cross.
*.dep
*.xyz
201102
*jbsed.xyz
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
Using ArcMap 9.2 and VACExtras v 2.1 (extension developed by the USGS in Woods Hole) these XYZ files are converted to shapefiles. The tool in VACExtras to do this is "convert resistivity to shapefile". This tool requires the data frame be in a UTM projection, the active layer in the data frame needs to be a polyline shapefile with one record selected (the polyline navigation file) and the user is prompted for the file from justbelowsed.m. The program uses the distance along value to find an actual latitude and longitude. The software assumes the datum of the data layer and the data frame projection are the same. The conversion of the Easting and Northing locations to latitudes and longitudes is done by the tool. The result is a point shapefile with 11 columns of information. The Id attribute is automatically generated upon creation of a shapefile, the "line" attribute is the line name as indicated within the polyline shapefile that the program prompts the user for, "dist" is the distance along attribute carried over from the MATLAB file, the attributes of location information (latitude, longitude, utmx, utmy) are calculated by the tool, the attributes depth, dep_b_sed, resvalue, and reslogval are carried over from the MATLAB file. The Entity and Attribute section further describes these attributes and their units. An individual point shapefile is generated for each CRP polyline. In some instances of a sharp turn during data collection, the resistivity processing will split the line into multiple parts. On April 14, no lines had to be split during the resistivity processing.
jd104gps_lines.shp
all the individual MATLAB generated *jbsed.xyz files from this day
201102
*jbsed.shp
With all the individual point shapefiles from April 14, 2010 in ArcMap 9.2, ArcToolbox - Data management Tools - General - Merge was used to combine the individual files into a single shapefile. The input was all the individual point shapefiles, with the output being mrgapr14_allxyzres.shp. The field mapping was left at the defaults as all the input shapefiles have the same attributes.
*jbsed.shp
201102
mrgapr14_allxyzres.shp
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. Moved the minimal source information provided to make it the first process step. 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.
20171002
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
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
Vector
Entity point
710318
0.000001
0.000001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.257224
Local surface
0.1
meters
Attribute values
mrgapr14_allxyzres
ESRI point shapefile
ESRI
FID
Internal feature number.
ESRI
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
ESRI
Coordinates defining the features.
Id
An automatically generated numeric value.
VACExtras v 2.1
0
0
line
The alphanumeric name corresponding to the prefix of the GPS filename. This name reflects the name assigned to the line of data acquisition and incorporates modifiers (part1, part2) to reflect modification of the GPS file if the GPS file was split into more than one part. Additionally, the name incorporates a modifier (a,b) if the resistivity line was split into more than one part during processing.
U.S. Geological Survey
Character set.
dist
Distance along line in meters. Originally calculated by the AGI processing software and assumed to be based on the UTM projection appropriate for the area (UTM, Zone 18).
Processing software calculated.
0.1
9485.3
meters
longitude
Longitude position of the point (decimal degrees, WGS84)
Processing software calculated (VACExtras - convert resistivity to shapefile).
-75.194306
-75.074833
decimal degrees
latitude
Latitude position of the point (decimal degrees, WGS84)
Processing software calculated (VACExtras - convert resistivity to shapefile).
38.571023
38.61521
decimal degrees
utmx
Easting position of the point in meters (UTM, Zone 18, WGS84)
Processing software calculated (VACExtras - convert resistivity to shapefile).
483077.7
493484.8
meters
utmy
Northing position of the point in meters (UTM, Zone 18, WGS84)
Processing software calculated (VACExtras - convert resistivity to shapefile).
4269189.7
4274082.1
meters
depth
Depth (meters) of the resistivity value below the water surface. This value is not corrected for tides or transducer draft.
Acquisition software derived.
-12.32
-0.36
meters
dep_b_sed
Depth (meters) of the resistivity value below the sediment/water interface.
Processing software derived (MATLAB - justbelowsed.m).
-11.96
0
meters
resvalue
Resistivity value of the data point in ohm-m.
Processing software calculated (AGI EarthImager).
0.1
114.968
ohm-m
reslogval
Log(10) of the resistivity value.
Processing software calculated (MATLAB justbelowsed.m).
-1
2.060577
Log(10) of ohm-m
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.
Shapefile
ArcGIS 9.2
This WinZip (v. 14) file contains the point shapefile as well as the associated metadata files.
17.1
https://pubs.usgs.gov/of/2011/1039/data/resistivity/shapefile/mrgapr14_allxyzres.zip
https://pubs.usgs.gov/of/2011/1039/html/ofr2011-1039-catalog.html
https://doi.org/10.3133/ofr20111039
None.
This zip file contains data available in Esri point shapefile format. The user must have software capable of uncompressing the zip file and reading/displaying the shapefile.
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