2006060711094400FALSE20080225135518002008022513551800{2E43FE60-ACC9-4462-8CD4-C2464BABA1CD}Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.780enContinuous resistivity profiling (CRP) surveys were conducted at Cape Cod National Seashore in 2004 and 2006 in order to test hypotheses about groundwater flow under and into estuaries and the Atlantic Ocean. Coastal resource managers here and elsewhere are concerned about nutrients that are entering coastal waters via submarine groundwater discharge, which are contributing to eutrophication and harmful algal blooms. CRP is used to measure electrical resistivity of sediments, a property that is sensitive to differences in salinity of submarine ground water. The 2004 and 2006 surveys used floating resistivity streamers of 100 m and 50 m respectively. The depth penetration of the streamers is approximately 20% of the streamer length which translates to approximately 20-25 m with the 100 m streamer and 12-14 m with the 50 m streamer. These data were processed using AGI's EarthImager 2D software.To provide the linearized raw resistivity data collected by the AGI SuperSting system in the RES2DINV format.John F. Bratton2008RES2DINV Format Continuous Resistivity Profiles from Cape Cod National Seashore, Feb. 28, 2006feb28_res2dinv.txthttp://pubs.usgs.gov/of/2006/1169/data/res_data/2006/res2dinv_format/feb28_res2dinv.zipSubmarine Hydrogeological Data from Cape Cod National SeashoreVeeAnn A. CrossJohn F. BrattonJohn CrusiusJohn A. ColmanTimothy D. McCobb2008Open-File Report2006-1169Woods Hole Science Center, Woods Hole, MAU.S. Geological Survey, Coastal and Marine Geology Programhttp://pubs.usgs.gov/of/2006/1169/Open-File Report2006-1169Woods Hole Science Center, Woods Hole, MAU.S. Geological Survey, Coastal and Marine Geology Programhttp://pubs.usgs.gov/of/2006/1169/htmldocs/catalog.htmground condition20060228None planned-69.973172-69.94535041.83693341.820967GeneralCMGPCoastal and Marine Geology ProgramContinuous Resistivity ProfilingCRPground-waterOF 2006-1169Open-File Reportsubmarine ground-waterU.S. Geological SurveyUSGSWoods Hole Science CenterWHSC field activity serial number 06007GeneralAtlantic OceanCape CodMassachusettsNorth AmericaUnited StatesSalt PondNauset MarshgeoscientificInformationinlandWaterslocationISO 19115 Topic CategoryoceansNone.The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.Text FileJohn F. BrattonU.S. Geological Surveymailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598508-548-8700 x2254508-457-2210jbratton@usgs.govMicrosoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.780feb28_res2dinv.txtenFGDC Content Standards for Digital Geospatial MetadataFGDC-STD-001-1998local timeVeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.gov20080225http://www.esri.com/metadata/esriprof80.htmlESRI Metadata ProfileISO 19115 Geographic Information - MetadataDIS_ESRI1.0datasetDownloadable DataNeither 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.John F. BrattonU.S. Geological Surveymailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2254(508) 457-2310jbratton@usgs.govRES2DINVWinZip204 KB204 KBNone.These data are availabe in a format compatible with the RES2DINV resistivity inversion software. The user must have software capable of reading this format in order to process the data.002Text File20080225The data were transferred from the logging computer via AGISSAdmin software. The data files available for this day are l1*, l2*, l3*, l4*, l5*, l6*, l8*, l9*, l10*, l11*, l12*, l13*, l14*, and l15*. ***Of note, on lines 1 and 2, during acquisition the distance between the cable connection point and the first electrode was entered as 10 meters instead of -10 meters. This can be adjusted when reading the data into Marine Log Manager for linearization.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.gov$GPRMC lines with the GPS file that had bad time stamps or were otherwise corrupt were deleted.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govThe resistivity data were merged with the navigation data 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). In some instances, only a portion of the line was exported for processing. In particular, turns are removed before processing. (AGISSAdmin version 1.33.182). ***Note. When reading in l1 and l2, the GPS offset needs to be set to 10 to account for an incorrect acquisition paramger indicating the distance between the cable connection point and the first electrode.AGISSAdmin version 1.33.182; MLM version 1.03.92006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govThe file was then exported to a new STG file, and accompanying DEP file. The DEP file contains the distance along line and bathymetry values.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govThese data were acquired with an AGI SuperSting Marine system that is described at the website: www.agiusa.com/marinesystem.shtml. The particular system used for this acquisition was an 11 electrode array with electrodes spaced 5 meters apart. The potential electrodes are made of graphite, with the remaining electrodes 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 potentials between electrode pairs in the remaining electrodes. Each line of data acquisition records several files. The two files necessary for processing are the *.stg and *.gps file. The STG file contains the resistivity data, while the GPS file contains the navigation information including bathymetry. GPS and bathymetry data acquired with a Lowrance system.In most cases, nearshore values were very important. For that reason, the whole linearized STG file was selected for export. This applied in the following lines: l1, l2, l4, l5, l6, l9, l11, l12 and l14. The way the Marine Log Manager software works, the first value exported is where at least one of the electrodes has a known navigational fix. But the rest of the streamer electrodes at this position have a negative distance along line. When this export option is chosen, no DEP file is output. In order to create a DEP file, a second export file is needed. This one selects only positive electrode positions for export.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govThe linearized STG file with negative values is processed with EarthImager version 2.01 in order to determine the most negative position (available from the final XYZ output file). Once this is done, I can create a navigation fix for that negative distance along line. Based on the trackline created from the GPS data, I run an ArcView 3.3 avenue script (extendline.ave) which uses a straight-line tow path assumption of the first 2 points to create an additional point at the negative distance input. Essentially I extend the line at the start of the line.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govWith this new point I can modify the DEP file generated by the positive only electrode position export. I add in the negative distance along, as well as all the supplemental information, including the header information describing the latitude and longitude position of the start of line. So now I have a linearized STG file, as well as the accompanying DEP file for those files with negative distances along line.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govThe DEP file was checked for anomalous bathymetry values, or duplicated distance along values, and those lines in the file were deleted.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govEarthImager 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. On this survey, an instrument was used periodically to measure water conductivity. This value was converted to appropriate resistivity units and added to the DEP file. A value of 0.2 was used in all the files.2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govThe STG and DEP file were converted to a format suitable for the RES2DINV processing software. The conversion was accomplished by a Visual Basic 6 program written at the USGS office in Woods Hole (AGI2res2d.exe).2006VeeAnn A. CrossU.S. Geological SurveyMarine Geologistmailing and physical address384 Woods Hole Rd.Woods HoleMA02543-1598(508) 548-8700 x2251(508) 457-2310vatnipp@usgs.govOnly those lines with valid resistivity data are represented here.