Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Corsica River Estuary, Maryland on May 15, 2007 on USGS Cruise 07005

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Frequently anticipated questions:

What does this data set describe?
Who produced the data set?
Why was the data set created?
How was the data set created?
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Who wrote the metadata?

What does this data set describe?

Title:

Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Corsica River Estuary, Maryland on May 15, 2007 on USGS Cruise 07005

Abstract:

Submarine groundwater discharge (SGD) into Maryland's Corsica River Estuary was investigated as part of a larger study to determine the importance of nutrient delivery to Chesapeake Bay via this pathway. Resource managers are concerned about nutrients that are entering the estuary via submarine groundwater discharge from this primarily agricultural watershed that may be contributing to eutrophication, harmful algal blooms, and fish kills. An interdisciplinary U.S. Geological Survey (USGS) science team conducted field operations in the estuary in April and May 2007. Techniques used included continuous resistivity profiling (CRP), piezometer sampling, seepage meter measurements, and collection of a radon tracer time series. Better understanding of the style, locations, and rates of groundwater discharge could lead to improved models and mitigation strategies for estuarine nutrient over-enrichment in the Corsica River Estuary, and other similar settings. More information on the field work can be accessed from the Woods Hole Coastal and Marine Science Center Field Activity webpage: https://cmgds.marine.usgs.gov/fan_info.php?fan=2007-005-FA.

How might this data set be cited?
Bratton, John F., and Cross, VeeAnn A., 2011, Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Corsica River Estuary, Maryland on May 15, 2007 on USGS Cruise 07005: Open-File Report 2010-1094, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.
Online Links:
This is part of the following larger work.
Cross, VeeAnn A., Bratton, John F., Worley, Charles R., Crusius, John, and Kroeger, Kevin D., 2011, Continuous resistivity profiling data from the Corsica River Estuary, Maryland: Open-File Report 2010-1094, U.S. Geological Survey, Reston, VA.
Online Links:
- https://pubs.usgs.gov/of/2010/1094/
What geographic area does the data set cover?
West_Bounding_Coordinate: -76.126683
East_Bounding_Coordinate: -76.106167
North_Bounding_Coordinate: 39.090933
South_Bounding_Coordinate: 39.072400
What does it look like?
Does the data set describe conditions during a particular time period?

Calendar_Date: 15-May-2007
Currentness_Reference:

ground condition
What is the general form of this data set?
How does the data set represent geographic features?
1. How are geographic features stored in the data set?
2. What coordinate system is used to represent geographic features?
  Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Degrees and decimal minutes. The horizontal datum used is North American Datum of 1983.
  The ellipsoid used is Geodetic Reference System 80.
  The semi-major axis of the ellipsoid used is 6378137.000000.
  The flattening of the ellipsoid used is 1/298.257222.
  
  Vertical_Coordinate_System_Definition:
  Depth_System_Definition:
  Depth_Datum_Name: Local surface
  Depth_Resolution: 0.1
  Depth_Distance_Units: meters
  Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
How does the data set describe geographic features?

Who produced the data set?

Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
- John F. Bratton
- VeeAnn A. Cross
Who also contributed to the data set?
To whom should users address questions about the data?

John F. Bratton

U.S. Geological Survey

Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2254 (voice)

(508) 457-2310 (FAX)

jbratton@usgs.gov

Contact_Instructions:
Current address: NOAA/GLERL 4840 S. State Rd. Ann Arbor MI 48108-9719 734-741-2235 John.Bratton@noaa.gov

Why was the data set created?

The purpose of this dataset is to provide the raw resistivity data collected on May 15, 2007 in the Corsica River Estuary by the AGI SuperSting system. Modifications to the raw data were necessary in order to prepare the data for processing.

How was the data set created?

From what previous works were the data drawn?
How were the data generated, processed, and modified?
Date: 2007 (process 1 of 10)
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 ¼ 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 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.
Date: 2007 (process 2 of 10)
The data were transferred from the logging computer via AGISSAdmin software version 1.3.2.165. The data files available for this day are L1F1*, L2F1*, L3F1*, L4F1*, F5L1*, L6F1*, L7F1*, L8F1*, L9F1*, L9F2*, L10F1*, L11F1*, L12F1*, L12F2*, L13F1*. These files were then transferred via a thumb drive to the processing computer. The files included in this publication are the *.crs, *.cmd, *.gps, and *.stg. The two files essential for processing are the GPS and STG files. The GPS file contains the navigation, and in the case of the Lowrance system also includes water depth and temperature. The STG file contains the resistivity measurements from each of the electrodes. The CRS file contains the contact resistance readings. The CMD file contains the parameters for data collection. These last two files aren't necessary for data processing, but can be useful in terms of troubleshooting. This process step and all subsequent process steps were performed by the same person - VeeAnn A. Cross. Person who carried out this activity:

VeeAnn A. Cross

U.S. Geological Survey

Marine Geologist

Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2251 (voice)

(508) 457-2310 (FAX)

vatnipp@usgs.gov

Date: 2007 (process 3 of 10)
The first step is to check the navigation recorded in the *.gps file for each line of acquisition. At first glance, the navigation data in the files seem fine so I ran an AWK script which extracts the navigation, bathymetry, and temperature information recorded in each individual GPS data file. (* refers to the line name, which for this day are L1F1, L2F1, L3F1, L4F1, F5L1, L6F1, L7F1, L8F1, L9F1, L9F2, L10F1, L11F1, L12F1, L12F2, L13F1.)
```
AWK script "awkgps":
BEGIN {
FS = ","
}
{
FS = ","
ARGC = 2
depth = -9999
temp = -9999
if ($1=="$GPRMC")
	{
	utctime = $2
	latdeg = substr($4,1,2)
	latmin = substr($4,3,6)
	declat = latdeg + (latmin/60)
	londeg = substr($6,1,3)
	lonmin = substr($6,4,6)
	declon = -1 * (londeg + (lonmin/60))
	holddepth = -9999
	}
if ($1=="$SDDPT")
	{
	depthreal = $2
	holddepth = depthreal
	}
if ($1=="$SDMTW")
	{
	temp = $2
	if (holddepth > -1) {
		printf("%s, %9.6f, %9.6f, %3.1f, %4.1f, %s\n", utctime, declon, declat, holddepth, temp, ARGV[2])
	}
	else {
		printf("%s, %9.6f, %9.6f, %3.1f, %4.1f, %s\n", utctime, declon, declat, depth, temp, ARGV[2])
	}
	holddepth = -9999
	}
}
```
This AWK script was initialized by "doawk" - shell script run under CYGWIN (UNIX like environment that runs under Windows):
```
files=`ls *.gps | cut -d. -f1 | tr "[A-Z"] ["a-z"]`
for file in $files
do
	awk -f awkgps $file.gps $file > $file.txt
done
```
Person who carried out this activity:

VeeAnn A. Cross

U.S. Geological Survey

Marine Geologist

Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2251 (voice)

(508) 457-2310 (FAX)

vatnipp@usgs.gov

Data sources used in this process:
- *.gps
Data sources produced in this process:
- *.txt
Date: 2007 (process 4 of 10)
These files were then appended to each other using the UNIX cat command. cat l1f1.txt l2f1.txt l3f1.txt l4f1.txt f5l1.txt l6f1.txt l7f1.txt l8f1.txt l9f1.txt l9f2.txt l10f1.txt l11f1.txt l12f1.txt l12f2.txt l13f1.txt > day1gps.txt Person who carried out this activity:

VeeAnn A. Cross

U.S. Geological Survey

Marine Geologist

Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2251 (voice)

(508) 457-2310 (FAX)

vatnipp@usgs.gov

Data sources used in this process:
- *.txt
Data sources produced in this process:
- day1gps.txt
Date: 2007 (process 5 of 10)
VI under CYGWIN was used to add the appropriate header line and the comma-delimited text file was imported to ArcMap 9.2: Tools - Add XY Data. The X field is longitude; Y field is latitude, and the Coordinate System was defined as Geographic, NAD83. Visual inspection indicated that L1F1 has a spurious navigation fix. This bad point, along with the corresponding resistivity streamer electrodes values had to be removed before the file could be processed. Navigation from all the other lines from this day were fine. The modified GPS file is called L1F1_mod.gps. Both the original and modified versions of this file are include in the dataset. Person who carried out this activity:

VeeAnn A. Cross

U.S. Geological Survey

Marine Geologist

Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2251 (voice)

(508) 457-2310 (FAX)

vatnipp@usgs.gov

Data sources used in this process:
- day1gps.txt
Date: 2007 (process 6 of 10)
After the initial processing, it became apparent that I needed to exclude a set of electrode readings from L2F1 that causes an anomaly in the water column. The easiest way to do this is to delete the corresponding navigation point as the Marine Log Manager (MLM) software only processes those electrodes with corresponding navigational fixes. For this reason I removed the $GPRMC, $SDDPT and $SDMTW readings corresponding to the time 154829. Although the anomaly is found after some processing, the edit is made to the raw data - hence the reason for recording this information with the raw data. The modified GPS file is called L2F1_mod.gps. Both the original and the modified are included in this dataset. Person who carried out this activity:

VeeAnn A. Cross

U.S. Geological Survey

Marine Geologist

Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2251 (voice)

(508) 457-2310 (FAX)

vatnipp@usgs.gov

Data sources used in this process:
- L2F1.gps
Data sources produced in this process:
- L2F1_mod.gps
Date: 18-Oct-2017 (process 7 of 10)
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. Reordered the links in the identification section to have a landing page link as the first link. 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. 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. Person who carried out this activity:

U.S. Geological Survey

Attn: VeeAnn A. Cross

Marine Geologist

384 Woods Hole Road
Woods Hole, MA

508-548-8700 x2251 (voice)

508-457-2310 (FAX)

vatnipp@usgs.gov

Date: 20-Jul-2018 (process 8 of 10)
USGS Thesaurus keywords added to the keyword section. Person who carried out this activity:

U.S. Geological Survey

Attn: VeeAnn A. Cross

Marine Geologist

384 Woods Hole Road
Woods Hole, MA

508-548-8700 x2251 (voice)

508-457-2310 (FAX)

vatnipp@usgs.gov

Date: 18-Nov-2019 (process 9 of 10)
Crossref DOI link was added as the first link in the metadata. Person who carried out this activity:

U.S. Geological Survey

Attn: VeeAnn A. Cross

Marine Geologist

384 Woods Hole Road
Woods Hole, MA

508-548-8700 x2251 (voice)

508-457-2310 (FAX)

vatnipp@usgs.gov

Date: 08-Sep-2020 (process 10 of 10)
Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:

U.S. Geological Survey

Attn: VeeAnn A. Cross

Marine Geologist

384 Woods Hole Road
Woods Hole, MA

508-548-8700 x2251 (voice)

508-457-2310 (FAX)

vatnipp@usgs.gov
What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

How well have the observations been checked?
How accurate are the geographic locations?
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.
How accurate are the heights or depths?
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 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.
Where are the gaps in the data? What is missing?
Files L12F1, L12F2 and L13F1 did not have bathymetry values in the navigation files. All other files from this day did have fathometer data.
How consistent are the relationships among the observations, including topology?
Information unavailable from original metadata.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints	None.
Use_Constraints	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.

Who distributes the data set? (Distributor 1 of 1)

VeeAnn A. Cross

U.S. Geological Survey

Marine Geologist

Woods Hole Coastal and Marine Science Center
Woods Hole, MA

(508) 548-8700 x2251 (voice)

(508) 457-2310 (FAX)

vatnipp@usgs.gov
What's the catalog number I need to order this data set? Downloadable Data
What legal disclaimers am I supposed to read?
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.

How can I download or order the data?

Availability in digital form:

Data format:	The WinZip (version 9.0) file contains all the raw CRP data from May 15, 2007 as well as the associated metadata files. in format TEXT Size: 0.456
Network links:	https://pubs.usgs.gov/of/2010/1094/html/catalog.html https://pubs.usgs.gov/of/2010/1094/data/resistivity/raw_resis/may15_raw.zip
Media you can order:	DVD-ROM (Density 4.75 GBytes) (format UDF)

Cost to order the data: none

What hardware or software do I need in order to use the data set?
The data are provided in a WinZip compressed file. The user must have software capable of uncompressing the archive. In addition, the raw data are available in a format compatible with AGI Geosciences Marine Log Manager software. The user must have software capable of reading the AGI format in order to process these data.

Who wrote the metadata?

Dates:

Last modified: 18-Mar-2024

Metadata author:

VeeAnn A. Cross

U.S. Geological Survey

Marine Geologist

Woods Hole Coastal and Marine Science Center

Woods Hole, MA

(508) 548-8700 x2251 (voice)

(508) 457-2310 (FAX)

whsc_data_contact@usgs.gov

Contact_Instructions:

The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240318)

Metadata standard:

FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2010-1094/may15_rawmeta.faq.html>