PCCT measurements of stress and strain during direct shear tests of fine-grained sediment collected from Area C, Krishna-Godavari Basin during India's National Gas Hydrate Program, NGHP-02

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What does this data set describe?

Title:
PCCT measurements of stress and strain during direct shear tests of fine-grained sediment collected from Area C, Krishna-Godavari Basin during India's National Gas Hydrate Program, NGHP-02
Abstract:
Understanding how effectively methane can be extracted from a gas hydrate reservoir requires knowing how compressible, permeable, and strong the overlying seal sediment is. This data release provides results for flow-through permeability, consolidation, and direct shear measurements made on fine-grained seal sediment from Site NGHP-02-08 offshore eastern India. The sediment was collected in a pressure core from the Krishna-Godavari Basin during the 2015 Indian National Gas Hydrate Program Expedition 2 (NGHP-02). Gas hydrate is a crystalline solid that forms naturally in the sediment of certain marine and permafrost environments where pressure is relatively high (equivalent to the pressure measured at ~300 meters water depth or more) and temperature is relatively low (but generally above freezing). The concentration of methane can be high enough to make certain gas hydrate occurrences potentially relevant as energy resources. To extract methane from gas hydrate, the in situ formation (generally a coarse-grained, gas-hydrate-bearing sediment interval) can be depressurized by drawing pore water out through a production well. As the pore pressure falls below the gas hydrate stability limit, the solid gas hydrate breaks down, releasing gas and water that migrate toward the production well for collection.
How effectively the production well can depressurize the gas-hydrate-bearing interval depends on how permeable the overlying seal sediment is. If the seal is permeable, depressurizing the reservoir to extract methane causes water to flow out of the seal and into the reservoir. This can limit the ability of the production well to maintain the low reservoir pressure required to break down gas.
Supplemental_Information:
In addition to funding from the U.S. Geological Survey Gas Hydrate Project, this work is sponsored in part by the Department of Energy through an interagency agreement (DE-FE0023495). More information about the project can be found at: https://www.netl.doe.gov/research/oil-and-gas/project-summaries/methane-hydrate/fe0023495-usgs. This work is also part of the NGHP-02 expedition. Links to related data and publications within the NGHP-02 project are collected in the USGS Field Activity Report 2015-023-FA, found at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-023-FA.
  1. How might this data set be cited?
    Jang, Junbong, 2018, PCCT measurements of stress and strain during direct shear tests of fine-grained sediment collected from Area C, Krishna-Godavari Basin during India's National Gas Hydrate Program, NGHP-02: data release DOI:10.5066/P91XJ7DP, 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.

    Jang, Junbong, Dai, Sheng, Yoneda, Jun, Waite, William F., Collett, Timothy S., and Kumar, Pushpendra, 2018, Pressure core characterization tool measurements of compressibility, permeability, and shear strength of fine-grained sediment collected from Area C, Krishna-Godavari Basin, during India's National Gas Hydrate Program Expedition NGHP-02: data release DOI:10.5066/P91XJ7DP, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Jang, J., Dai, S., Yoneda, J., Waite, W.F., Collett T.S., and Kumar, P., 2018, Pressure core characterization tool measurements of compressibility, permeability, and shear strength of fine-grained sediment collected from Area C, Krishna-Godavari Basin, during India's National Gas Hydrate Program Expedition NGHP-02: U.S. Geological Survey data release, https://doi.org/10.5066/P91XJ7DP.
    This dataset supports the following publication:
    Jang, J., Dai, S., Yoneda, J., Waite, W.F., Stern, L.A., Boze, L.-G., Collett, T.S., and Kumar, P., 2018. Pressure core analysis of geomechanical and fluid flow properties of seals associated with gas hydrate-bearing reservoirs in the Krishna-Godavari Basin, offshore India: Marine and Petroleum Geology, https://doi.org/10.1016/j.marpetgeo.2018.08.015.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: 82.924221
    East_Bounding_Coordinate: 82.924222
    North_Bounding_Coordinate: 16.581168
    South_Bounding_Coordinate: 16.581167
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5b69af43e4b006a11f774f11?name=NGHP02_AreaC_Direct_Shear_BrowseGraphic.png (PNG)
    Direct Shear Chamber (DSC) used for the obtaining the data in this data release.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 03-Jul-2015
    Currentness_Reference:
    ground condition of the field activity when the original pressure core that was subsampled for this study was collected
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (969)
    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 0.0000001. Longitudes are given to the nearest 0.0000001. Latitude and longitude values are specified in decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Meters below sea floor
      Depth_Resolution: 1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    NGHP02_AreaC_Direct_Shear_Data
    Vertical and horizontal stress and strain data for direct shear tests of fine-grained NGHP-02 (Krishna-Godavari Basin, offshore India) seal sediment from Site NGHP-02-08 (Source: U.S. Geological Survey)
    Site
    Site: NGHP-02 site name designation. Format is: Expedition Name (NGHP-02)-Site Number and Hole Designation Letter. Hole A was used only for logging-while-drilling (no core recovery). Holes B and C were used for coring. (Source: U.S. Geological Survey) Character set (text).
    J-CORES section ID
    SectionID: Unique, sequential identifier given at the time of collection to any shipboard core section. Cores were collected on the D/V Chikyu, so each ID begins with CKY. (Source: Shipboard science party, D/V Chikyu) Character set (text).
    Latitude (degrees, minutes, seconds)
    Latitude_DMS: Latitude coordinate, in degrees (°) minutes (’) decimal seconds (”), of the sample’s location. North latitude recorded as positive values. Data release describes measurements from a single core, so the location information is single-valued. (Source: Shipboard science party, D/V Chikyu)
    Range of values
    Minimum:16°34'52.206"
    Maximum:16°34'52.206"
    Units:degrees (°) minutes (’) decimal seconds (”)
    Longitude (degrees, minutes, seconds)
    Longitude_DMS: Longitude coordinate, in degrees (°) minutes (’) decimal seconds (”), of the sample’s location. East longitude is recorded as positive values. Data release describes measurements from a single core, so the location information is single-valued. (Source: Shipboard science party, D/V Chikyu)
    Range of values
    Minimum:82°55'27.198"
    Maximum:82°55'27.198"
    Units:degrees (°) minutes (’) decimal seconds (”)
    Latitude (decimal degrees)
    Lat_DD: Latitude coordinate, in decimal-degrees, of sample’s location. North latitude recorded as positive values. (Source: U.S. Geological Survey)
    Range of values
    Minimum:16.58116833
    Maximum:16.58116833
    Units:decimal degrees
    Longitude (decimal degrees)
    Long_DD: Longitude coordinate, in decimal degrees, of the sample’s location. East longitude is recorded as positive values. (Source: U.S. Geological Survey)
    Range of values
    Minimum:82.92422167
    Maximum:82.92422167
    Units:decimal degrees
    Core Subsection
    Subsection: Core NGHP-02-08-30P was cut into several subsections for testing. Each subsection was tested in either the Direct Shear Chamber (DSC) or Effective Stress Chamber (ESC). The section number begins with 1 as the deepest subsection for the core, and increases for subsections taken higher up in the core. (Source: U.S. Geological Survey) Character set (text).
    Top Depth in CSF-B (mbsf)
    CSFB_TopDepth_mbsf: Depth of the top of the subsection in meters below the sea floor (mbsf), using the CSF-B convention in which gas expansion gaps, if present at the time of core recovery, have been removed. (Source: Shipboard science party, D/V Chikyu)
    Range of values
    Minimum:247.12
    Maximum:247.12
    Units:meters
    Bottom Depth in CSF-B (mbsf)
    CSFB_BottomDepth_mbsf: Depth of the bottom of the subsection in meters below the sea floor (mbsf), using the CSF-B convention in which gas expansion gaps, if present at the time of core recovery, have been removed. (Source: Shipboard science party, D/V Chikyu)
    Range of values
    Minimum:247.28
    Maximum:247.28
    Units:meters
    Before or After Dissociation
    Dissociation: Direct shear tests were made on the specimen tested here before and after the pore pressure was reduced below atmospheric pressure (depressurization was accomplished at a constant effective stress by simultaneously controlling the vertical load and the pore pressure). For data collected prior to the depressurization, this column contains the word "Before." For data collected after the depressurization, this column contains the word "After." (Source: U.S. Geological Survey) Character set (text).
    Loading or Unloading
    LoadState: The first two direct shear tests were made after consolidation steps for which the effective vertical stress had been increased (designated in this column as "Loading"). The third direct shear tests was run after a consolidation step for which the effective vertical stress had been decreased (designated in this column as "Unloading"). The fourth direct shear tests was made after a consolidation step for which the effective vertical stress had been increased (designated in this column as "Reloading"). The fifth and final direct shear tests was run after a consolidation step for which the effective vertical stress had been decreased (designated in this column as "Unloading"). (Source: U.S. Geological Survey) Character set (text).
    Vertical Effective Stress (Megapascal)
    Vert_Eff_Stress_MPa: This is the 1-dimensional (vertical) stress applied to the specimen during the direct shear test. (Source: U.S. Geological Survey)
    Range of values
    Minimum:2.005
    Maximum:6.958
    Units:megapascals
    Horizontal Strain (unitless)
    Hor_Strain: Horizontal strain is the change in the position of the shearing ring divided by the diameter of the core. (Source: U.S. Geological Survey)
    Range of values
    Minimum:0
    Maximum:0.19279485
    Units:None
    Vertical Strain (unitless)
    Vert_Strain: Vertical strain is the change in the height of the specimen divided by the diameter of the core. If the result is negative, the specimen is getting shorter. If the answer is positive, the shearing process is causing the specimen to get taller. Blank elements in this column indicate data points for which the height measurement was too noisy to confidently determine a value. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-0.002578412
    Maximum:0.000131986
    Units:None
    Shear-to-Effective-Vertical Stress Ratio (unitless)
    Stress_Ratio: The stress ratio is the ratio of the shear stress divided by the vertical effective stress. The behavior of this ratio as a function of the horizontal strain indicates the shear strength of the specimen as well as the mode of shearing (for instance, a case where the stress ratio shows a peak or maximum shear strength compared with a work hardening case where the stress ratio simply increases with horizontal strain). (Source: U.S. Geological Survey)
    Range of values
    Minimum:0
    Maximum:0.848038729
    Units:None
    Entity_and_Attribute_Overview:
    These data are available in a Microsoft Excel XLSX as well as a CSV format. The first two rows in the XLSX file are header rows, where the second row is an abbreviated column label intended for software packages that are unable to cope with longer labels available in the first row of the XLSX file. The first part of the attribute definition (before the colon) indicates the abbreviated column label. The first row of the CSV file is a header line and is the same as the abbreviated column label on the second row of the XLSX file.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Junbong Jang
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Junbong Jang
    Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2278 (voice)
    508-457-2310 (FAX)
    jjang@usgs.gov

Why was the data set created?

The purpose of this dataset is to report the strains (horizontal and vertical) and the stress ratio (shear stress normalized by the effective vertical stress) for a series of direct shear tests made on the fine-grained seal sediment collected in pressure core NGHP-02-08-30P using the Direct Shear Chamber.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 03-Jul-2015 (process 1 of 6)
    Deployment sample collection: This study used sediment from pressure core NGHP-02-08-30P, collected from Site NGHP-02-08 in Area C of the Bay of Bengal offshore Eastern India. Pressure core collection requires the rotary corer to retract the core through a ball valve and into an autoclave at the in situ coring depth. Once retracted into the autoclave, the ball valve at the base of the autoclave can be closed, sealing the core within the autoclave. A connected high-pressure nitrogen canister provides pressure stabilization as the autoclave is brought through different thermal regimes on the trip to the rig floor. Once the autoclave is recovered, it is chilled in an ice bath to stabilize the core contents, then transferred to a temperature-controlled unit for core manipulation. During NGHP-02, depth below sea floor was based on the continuous downhole log of the drill pipe length. The sea floor depth reference (mudline) was determined from a combination of noting when the drill string contacted the sea floor and increased the measured weight-on-bit, and visual verification of the drill bit position using an ROV. Here, depth is reported using the IODP standard depth terminology CSF-B (total depth from sea floor to target sediment, after all gas expansion gaps have been removed). Person who carried out this activity:
    U.S. Geological Survey
    Attn: William F. Waite
    Research Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2346 (voice)
    wwaite@usgs.gov
    Date: 2015 (process 2 of 6)
    Core preparation and transport: Note that throughout the core preparation, transport and testing stages, the hydrostatic pressure is maintained at or above in situ values to maintain the stability of the core contents and avoid the formation of gas bubbles. Once the core-filled autoclave was brought to the rig floor and its temperature was stabilized, the autoclave was transferred to a shipboard analysis laboratory. In the laboratory, a pressurized system extracted the core from the autoclave, cut the core to a prescribed length (1.2 meters for the NGHP-02-08-30P core described here), and inserted the 1.2 m-long section into a pressurized storage chamber. The storage chamber can then be isolated via a ball valve closure and, ultimately, shipped in a Department of Transportation-approved, refrigerated overpack system to the U.S. Geological Survey’s Woods Hole Coastal and Marine Science Center for analysis (WHCMSC). Person who carried out this activity:
    U.S. Geological Survey
    Attn: William F. Waite
    Research Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2346 (voice)
    wwaite@usgs.gov
    Date: 2017 (process 3 of 6)
    Pressure Core Characterization Tool (PCCT) Core Manipulation: Once the core storage chamber arrived at WHCMSC, it was moved into a refrigerated core storage facility to maintain the core’s temperature stability. The core was subsequently tested in the WHCMSC High Pressure Core Analysis Laboratory (HyPrCAL) using the PCCTs (see the browse graphic for this data releases primary landing page). Similar to the shipboard setup, the core was first retrieved, at pressure, from the storage chamber, then individual specimens were cut and inserted into either the Direct Shear Chamber (DSC) or Effective Stress Chamber (ESC). The core manipulation and transfer into the testing chambers was accomplished at a hydrostatic pressure between 10-11 MPa (Megapascal). Person who carried out this activity:
    U.S. Geological Survey
    Attn: Junbong Jang
    Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2278 (voice)
    508-457-2310 (FAX)
    jjang@usgs.gov
    Date: 2017 (process 4 of 6)
    Testing Chamber Overview: The DSC and its operations are described in Santamarina and others (2012, 2015). Briefly, once the specimen is isolated in the Direct Shear Chamber (DSC, see Browse Graphic), the sediment is extruded from the plastic core liner using a plunger that will eventually serve as the specimen’s top endcap once the specimen is pushed all the way out of the liner and into the primary testing space. The plunger is then used to apply a vertical effective stress, returning the specimen to its in situ state of effective stress (approximately 2 MPa). Additional vertical effective stress can be applied to test the specimen response to the increasing effective stress that will occur in situ when the formation is depressurized to extract methane from gas hydrate. The consolidation data measured while applying the full range of vertical stresses are provided in a separate data release within this larger work (see "PCCT measurements of the consolidation characteristics, constrained modulus and compressional wave velocity for fine-grained sediment collected from Area C, Krishna-Godavari Basin during India's National Gas Hydrate Program, NGHP-02" in Jang and others, (2018)). For the shear strength testing, a core specimen in the DSC is held in a three-layer specimen chamber. The middle layer can be horizontally moved, shearing the middle third of the approximately 15 cm-tall specimen along the top and bottom of the middle layer. In this data release, the following parameters are reported as functions of the applied effective vertical stress: the horizontal and vertical strain, and the ratio of shear stress to effective vertical stress. The strains (unitless) are measured using Linear Voltage Displacement Transducers, and are reported here with an accuracy of 1e(-8). Stresses are calculated from load cell measurements, and are reported here with an accuracy of 5 kPa (kilopascal).
    Jang, J., Dai, S., Yoneda, J., Waite, W.F., Collett T.S., and Kumar, P., 2018, Pressure core characterization tool measurements of compressibility, permeability, and shear strength of fine-grained sediment collected from Area C, Krishna-Godavari Basin, during India's National Gas Hydrate Program Expedition NGHP-02: U.S. Geological Survey data release, https://doi.org/10.5066/P91XJ7DP.
    Santamarina, J.C., Dai, S., Jang, J., and Terzariol, M., 2012, Pressure core characterization tools for hydrate-bearing sediments. Scientific Drilling, v. 14, p. 44-48.
    Santamarina, J.C., Dai, S., Terzariol, M., Jang, J., Waite, W.F., Winters, W.J., Nagao, J., Yoneda, J., Konno, Y., Fujii, T., and Suzuki, K., 2015, Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough. Marine and Petroleum Geology, v. 66, p. 434-450. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Junbong Jang
    Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2278 (voice)
    508-457-2310 (FAX)
    jjang@usgs.gov
    Date: 2017 (process 5 of 6)
    Direct Shear Chamber (DSC) direct shear measurement: To obtain the stress and strain data provided in this data release, a direct shear test is performed in the following fashion: A target vertical effective stress is applied to the specimen, and held until the specimen height becomes constant, meaning the specimen has finished consolidating to the extent required for that imposed vertical effective stress. A horizontal shear is induced by hydraulically forcing the ring containing the middle third of the specimen to slide horizontally at 1.9 millimeters per minute. The horizontal and vertical stresses and strains are tracked during this shearing. Once the middle ring has been displaced by 10 millimeters, the test is considered complete. The ring is pushed back into its original position, and a new vertical load is applied to the specimen. With the increased load, the specimen consolidates, and the shear planes are shifted below the upper and lower limits of the shearing ring. A subsequent shear test will therefore shear the specimen along a new pair of horizontal shear planes. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Junbong Jang
    Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2278 (voice)
    508-457-2310 (FAX)
    jjang@usgs.gov
    Date: 2017 (process 6 of 6)
    Data archiving: Microsoft Excel version 15.33 was used to consolidate all data in a spreadsheet. Measured interface heights and elapsed times were arranged by sediment and pore fluid type. Results were then exported to a comma-separated values (csv) file format. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Junbong Jang
    Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2278 (voice)
    508-457-2310 (FAX)
    jjang@usgs.gov
  3. What similar or related data should the user be aware of?

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

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    Horizontal position was determined by GPS satellite data, which provided guidance information for the dynamic positioning system (DPS) utilized by the D/V Chikyu. The DPS also utilizes inputs from tidal, wind and wave data to control six azimuthal thrusters beneath the ship’s hull. The thrusters are capable of 360 degree adjustment. Given the DPS capabilities, borehole locations for the D/V Chikyu are considered to be accurate to a radius of 15 meters. Details are provided in: Chikyu Hakken – Earth Discovery, Volume 1, Spring 2005, published by JAMSTEC’s Center for Deep Earth Exploration: https://www.jamstec.go.jp/chikyu/e/magazine/backnum/pdf/hk_01_e.pdf
  3. How accurate are the heights or depths?
    Coring depth measurements used on the D/V Chikyu during NGHP-02 followed standard International Ocean Drilling Program (IODP) protocols. Assessment of these protocols by IODP had determined the vertical position accuracy is on the order of centimeters to meters. Additional information about the depth conventions and accuracy are on pages 8 and 9 of the IODP report “IODP Depth Scales Terminology”: http://www.iodp.org/policies-and-guidelines/142-iodp-depth-scales-terminology-april-2011/file. Depth resolution ranges from 0.01 to 1 meter.
  4. Where are the gaps in the data? What is missing?
    This data release contains the stress and strain data associated with a set of direct shear tests using the DSC. Blank entries in the column of vertical strain reflect data points collected while the vertical strain measurement (via a Linear Voltage Displacement Transducer) was too noisy to acquire an accurate reading.
  5. How consistent are the relationships among the observations, including topology?
    Specimen collection via pressure core, and maintenance of high pore pressures throughout the specimen collection and testing process, is required because these are gassy sediment that potentially contain gas hydrate. Allowing these specimens to depressurize prior to testing would allow gas bubbles to form, expand, and disrupt the sediment fabric that determines the in situ moduli, permeability and strength reported in this data release.

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:
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.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? This dataset contains four files: NGHP02_AreaC_Direct_Shear_Data.xlsx (data in an Excel spreadsheet), NGHP02_AreaC_Direct_Shear_Data.csv (same data in a comma-separated text file), NGHP02_AreaC_Direct_Shear_BrowseGraphic.png (browse graphic), and FGDC CSDGM metadata in XML format.
  3. 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.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    These data are available in XLSX and CSV formats, and a browse graphic in PNG format. The user must have software capable of reading the data formats.

Who wrote the metadata?

Dates:
Last modified: 29-Jan-2019
Metadata author:
U.S. Geological Survey
Attn: William F. Waite
Geophysicist
384 Woods Hole Rd.
Woods Hole, MA

508-548-8700 x2346 (voice)
508-457-2310 (FAX)
wwaite@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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