Metadata: Identification_Information: Citation: Citation_Information: Originator: Carolyn D. Ruppel Originator: Arthur H. Lachenbruch Publication_Date: 2019 Title: USGS T-3 enhanced thermal data from T-3 Ice Island, 1963-73 Geospatial_Data_Presentation_Form: tabular digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P97EPU2F Publication_Information: Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA Publisher: U.S. Geological Survey, Coastal and Marine Hazards and Resources Program Online_Linkage: https://doi.org/10.5066/P97EPU2F Online_Linkage: https://www.sciencebase.gov/catalog/item/5d10eb42e4b0941bde550210 Larger_Work_Citation: Citation_Information: Originator: Carolyn D. Ruppel Originator: Deborah R. Hutchinson Originator: Arthur H. Lachenbruch Originator: John K. Hall Publication_Date: 2019 Title: Thermal Data and Navigation for T-3 (Fletcher's) Ice Island Arctic Ocean Heat Flow Studies, 1963-73 Geospatial_Data_Presentation_Form: tabular digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P97EPU2F Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Other_Citation_Details: Ruppel, C.D., Hutchinson, D.R., Lachenbruch, A.H., and Hall, J.K., 2019, Thermal data and navigation for T-3 (Fletcher's) ice island Arctic Ocean heat flow studies, 1963-73: USGS data release, https://doi.org/10.5066/P97EPU2F. Online_Linkage: https://doi.org/10.5066/P97EPU2F Online_Linkage: https://www.sciencebase.gov/catalog/item/5c65b826e4b0fe48cb390173 Description: Abstract: The T-3 (Fletcher's) Ice Island in the Arctic Ocean was the site of a scientific research station re-established by the Naval Arctic Research Laboratory starting in 1962. Starting in 1963, the USGS acquired marine heat flow data and coincident sediment cores at sites in Canada Basin, Nautilus Basin, Mendeleev Ridge, and Alpha Ridge as the ice island drifted in the Amerasian Basin. At least 584 heat flow penetrations were attempted, and data were reported at 356 of these. This dataset is the enhanced version of the original data table from Lachenbruch and others (2019; see cross-reference), incorporating additional information such as the probable dates of measurement, physiographic province and surficial geology at each station, and the length of recovered cores. In addition, this dataset converts the original units to SI units and the positions to decimal degrees. Purpose: To provide an enhanced version of the T-3 heat flow data with additional information about the heat flow stations and conversions to SI units. Supplemental_Information: This dataset is an enhanced version (data converted to modern units; additional information integrated) of Table 2 in: Lachenbruch, A.H., Marshall, B.V., and Ruppel, C.D., 2019, Post-expedition report for USGS T-3 Ice Island heat flow measurements in the High Arctic Ocean, 1963-1973: U.S. Geological Survey data release, https://doi.org/10.5066/P91XQ3IS. (See cross-reference.) Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1963 Ending_Date: 1973 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -176.70250 East_Bounding_Coordinate: -78.75000 North_Bounding_Coordinate: 86.05683 South_Bounding_Coordinate: 75.37100 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5d10eb42e4b0941bde550210 Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme_Keyword: oceans Theme_Keyword: location Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: marine geology Theme_Keyword: navigational data Theme_Keyword: field monitoring stations Theme_Keyword: heat flow (earth) Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: Woods Hole Coastal and Marine Science Center Theme_Keyword: WHCMSC Theme_Keyword: Lamont Geological Observatory Theme_Keyword: Lamont-Doherty Earth Observatory Theme_Keyword: marine heat flow Theme_Keyword: T-3 Ice Island Theme_Keyword: Fletcher's Ice Island Theme_Keyword: navigation Place: Place_Keyword_Thesaurus: None Place_Keyword: Alpha Ridge Place_Keyword: Mendeleev Ridge Place_Keyword: Nautilus Basin Place_Keyword: Canada Basin Place_Keyword: Chukchi Plateau Place_Keyword: Arctic Ocean Place_Keyword: Amerasian Basin Place_Keyword: Fletcher's Ice Island Place_Keyword: T-3 Ice Island Place: Place_Keyword_Thesaurus: Common geographic areas Place_Keyword: Arctic Access_Constraints: None. Please see 'Distribution Info' for details. Use_Constraints: Not to be used for navigation. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Carolyn Ruppel Contact_Organization: U.S. Geological Survey, Woods Hole Coastal and Marine Science Center Contact_Position: Research Geophysicist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Rd. City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: (508) 548-8700 x2339 Contact_Facsimile_Telephone: (508) 457-2310 Contact_Electronic_Mail_Address: cruppel@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/5d10eb42e4b0941bde550210?name=T3enhancedheatflowgraphic.jpg Browse_Graphic_File_Description: T-3 heat flow data labelled with the station number and color-coded by heat flow value. The background bathymetry is from: Jakobsson, M. and other (2012), The International Bathymetric Chart of the Arctic Ocean (IBCAO) Version 3.0, Geophys. Res. Lett., 39, L12609, doi:10.1029/2012GL052219. Browse_Graphic_File_Type: JPEG Data_Set_Credit: Dataset originally compiled by Lachenbruch et al. (2019)--see cross-reference. This version of the dataset converts original data to modern (SI) units and adds information about date of measurement, length of core obtained at the station, physiographic province, and surface geology. Native_Data_Set_Environment: Microsoft Windows 7 Enterprise edition; Microsoft Excel 2013 Cross_Reference: Citation_Information: Originator: Arthur H. Lachenbruch Originator: B. Vaughn Marshall Originator: C.D. Ruppel Publication_Date: 2019 Title: Post-expedition report for USGS T-3 Ice Island heat flow measurements in the High Arctic Ocean, 1963-1973 Geospatial_Data_Presentation_Form: PDF Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P91XQ3IS Publication_Information: Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA Publisher: U.S. Geological Survey, Coastal and Marine Hazards and Resources Program Other_Citation_Details: This dataset originated as Table 2 in: Lachenbruch, A.H., Marshall, B.V., and Ruppel, C.D., 2019, Post-expedition report for USGS T-3 Ice Island heat flow measurements in the High Arctic Ocean, 1963-1973: U.S. Geological Survey data release, https://doi.org/10.5066/P91XQ3IS. Online_Linkage: https://doi.org/10.5066/P91XQ3IS Online_Linkage: https://cmgds.marine.usgs.gov/data/field-activity-data/1963-001-FA/ Cross_Reference: Citation_Information: Originator: Ruppel, Carolyn D. Originator: Lachenbruch, Arthur H. Originator: Hutchinson, Deborah R. Originator: Munroe, Robert Originator: Mosher, David C. Publication_Date: 2019 Title: Heat Flow in the Western Arctic Ocean (Amerasian Basin) Series_Information: Series_Name: Journal of Geophysical Research Issue_Identification: DOI:10.1029/2019JB017587 Publication_Information: Publication_Place: Washington, D.C. Publisher: American Geophysical Union Other_Citation_Details: Ruppel, C.D., Lachenbruch, A.H., Hutchinson, D.R., Munroe, R., and Mosher, D.C., 2019, Heat flow in the Western Arctic Ocean (Amerasian Basin): J. Geophysical Research. Online_Linkage: https://doi.org/10.1029/2019JB017587 Cross_Reference: Citation_Information: Originator: University of Wisconsin-Madison Department Of Geoscience Publication_Date: 2016 Title: Archive of information about the Ice Island T3 piston core collection Geospatial_Data_Presentation_Form: publication Publication_Information: Publication_Place: n/a Publisher: NOAA National Centers for Environmental Information Online_Linkage: https://doi.org/10.7289/v51834g7 Cross_Reference: Citation_Information: Originator: Arthur H. Lachenbruch Originator: B. Vaughn Marshall Publication_Date: 1966 Title: Heat flow through the Arctic Ocean floor: The Canada Basin-Alpha Rise Boundary Series_Information: Series_Name: Journal of Geophysical Research Issue_Identification: vol. 71, issue 4 Publication_Information: Publication_Place: Washington, D.C. Publisher: American Geophysical Union (AGU) Other_Citation_Details: pp. 1223– 1248 Online_Linkage: https://doi.org/10.1029/JZ071i004p01223 Cross_Reference: Citation_Information: Originator: University Of Wisconsin-Madison Department Of Geoscience Publication_Date: 2016 Title: Archive of information about the Ice Island T3 piston core collection Geospatial_Data_Presentation_Form: NCEI data release Publication_Information: Publication_Place: n/a Publisher: NOAA National Centers for Environmental Information Online_Linkage: https://doi.org/10.7289/v51834g7 Cross_Reference: Citation_Information: Originator: Arthur H. Lachenbruch Originator: B. Vaughn Marshall Publication_Date: 1969 Title: Heat Flow in the Arctic Publication_Information: Publication_Place: Calgary, Alberta, Canada Publisher: Arctic Institute of North America Other_Citation_Details: pp. 300–311 Online_Linkage: www.jstor.org/stable/40507641 Cross_Reference: Citation_Information: Originator: Marcus G. Langseth Originator: Arthur H. Lachenbruch Originator: B. Vaughn Marshall Publication_Date: 1990 Title: Geothermal observations in the Arctic region Publication_Information: Publication_Place: Boulder, CO Publisher: Geological Society of America Other_Citation_Details: In: The Arctic Ocean Region, edited by A. Grantz, L. Johnson and J. F. Sweeney, Decade of North American Geology, Vol. L, Geological Society of America, pp. 133-152. Online_Linkage: https://doi.org/10.1130/DNAG-GNA-L.133 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: This is a legacy dataset collected between 1963 and 1973. To determine accuracy of the original data: Carolyn Ruppel attempted to locate original records at the USGS Menlo Park office and among Arthur Lachenbruch's scientific papers, which are in the possession of Barbara Lachenbruch of Corvalis, Oregon. Lacking the original records (logs, records of heat flow equilibration curves, records of benchtop thermal conductivity measurements), it is impossible to determine whether the derived information reported in this dataset is accurate. The dataset is assumed to be accurate based on material in Lachenbruch and others (2019)--(see cross-reference), which discusses calibrations, internal checks, and other measures taken to ensure that the collected data (geothermal gradients and thermal conductivity values) were of high quality and accuracy. The dataset includes percentage uncertainties on reported heat flow measurements for most of the heat flow stations. It is assumed that these uncertainties are propagated errors from the thermal gradients and thermal conductivities combined. Another accuracy issue concerns the quality of the transfer from the hardcopy table to the digital version. The data were first manually keyed by Carolyn Ruppel in 2016. Subsequently, the data were optically scanned to PDF format and a subset of the data were subjected to optical character recognition by B. Clark and M. Arsenault. The manually keyed and optically-character-recognized data were then quality controlled by Deborah Hutchinson, who made notes about parts of the table that were not legible in the scans and best determinations about the appropriate values. Hutchinson also identified locations that did not confirm to the known T-3 navigation track. The dataset contains JPEG graphics showing the initially digitized table beside the scanned PDF portion of the table, with identified problems marked. Logical_Consistency_Report: Dates are logical based on T-3 navigation track. Positions of measurements were checked to confirm that they lie on the known navigational track for T-1 as provided in this data release as part of the dataset "T-3 Ice Island One Hour Navigation: May 14, 1962 to September 15, 1974." Station FL-532 was correctly digitized but does not lie on the T-1 navigational track. Thermal gradients, thermal conductivity, and heat flow values are all positive and physically plausible. Average calculated thermal conductivity range does not agree with inferred conductivity range, indicating that original dataset may have had access to thermal conductivity data not included in the interval thermal conductivities. Completeness_Report: This file enhances the one released in "USGS T-3 original thermal gradient, thermal conductivity, and heat flow data from T-3 ice island, 1963-73." Refer to metadata for that dataset regarding completeness. In summary, all values present in the original PDF scan were included in that dataset, and a best guess was used when the data were unreadable. This enhanced dataset makes no modifications of the original data in that release and merely adds to that data. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Background on navigation is summarized in: Hunkins, K., and W. Tiemann (1977), Geophysical data summary for Fletcher's Ice Island (T-3), 1962-1974, Technical Report, Lamont-Doherty Survey of the World Ocean Rep. CU-1-77, 219 pp, Lamont-Doherty Geological Observatory and in the cross-referenced Journal of Geophysical Research paper associated with this release. See also "T-3 Ice Island One Hour Navigation: May 14, 1962 to September 15, 1974" within this data release. Before 1967, navigation relied on theodolite fixes of the sun (summer) and stars (winter) coupled with a chronometer that was frequently checked for accuracy via radio. Hunkins and Tiemann [1977] estimate a positional error of up to 1 km during the summer and 0.5 km in the winter for this period. Starting in 1967, satellite data from the Navy Navigation Satellite System provided positional fixes, and Hunkins and Tiemann [1977] estimate that positions were known within 250 m. Based on the years of the island's occupation, the horizontal datum is assumed to be NAD27. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The water depths reported in the data table accompanying the Lachenbruch and others (2019) report (see cross-reference) are apparently line-out depths for the heat flow apparatus. No additional information with regards to depth measurements is indicated, and no vertical coordinate system is specified. Note that Hunkins and Tiemann (1977) also collected depth measurements using seismic and subbottom profiling systems and these are reported in "T-3 Ice Island One Hour Navigation: May 14, 1962 to September 15, 1974" as part of this data release. It is not known whether these depth measurements were adopted for the heat flow and radiogenic heat datasets. Lineage: Process_Step: Process_Description: This process step gives an overview of the acquisition of the original data. This is copied from details given in this data release in metadata for dataset: "USGS T-3 original thermal gradient, thermal conductivity, and heat flow data from T-3 ice island, 1963-73." Details about the operations to acquire the data are given in Lachenbruch and others (2019)--see cross-reference. Summary information about procedures is also provided in the other cross-referenced publications, particularly the Journal of Geophysical Research paper by Ruppel and others (2019). The heat flow measurements were made once a day or once every several days (occasionally two per day) during USGS occupation of the T-3 ice island. The measurements were made through a permanent hole in the ice (moonpool) maintained under the protection of a hut near the Colby Bay portion of the T-3 ice island. The apparatus consisted of a corer with attached thermistors (four thermistors during the first few years of the operation and then five thermistors on a slightly longer core barrel during subsequent years). The thermistor closest to the bottom of the core barrel was designated as #1. Thermistor accuracy was 0.001 degrees Celsius based on Lachenbruch and others(2019). The corer with attached thermistors was lowered to the seafloor on a winch system. The probe remained in the bottom sediments long enough for the frictional heat pulse associated with sediment penetration to decay to the conductive part of the curve so that an equilibrium temperature could be determined for each thermistor during post-analysis. Thermal conductivity was not measured in situ in the seafloor. The probe was recovered with sediments in the corer. Far more sediment cores were recovered than heat flow measurements taken (for example, refer to the information in the University of Wisconsin NCEI dataset at https://doi.org/10.7289/v51834g7 for selected information about USGS T-3 sediment cores). It is unknown whether heat flow measurements were not attempted on every coring run or whether the heat flow probe or recording instrumentation suffered frequent problems. The consistent recovery of sediment cores indicates that the probe penetrated the sediments at many locations, meaning that a heat flow measurement was in theory possible at those locations as well. After completion of a measurement, data would have been analyzed to determine an equilibrium temperature for each thermistor. These equilibrium temperature data have been lost, as have the bottom water temperature data recorded during the surveys and information about the penetration depth of the probe. For the Journal of Geophysical Research paper by Ruppel and others (2019)--see cross-reference, attempts were made to use the lengths of recovered cores as an indicator of the probe's penetration depth to assist in determination of equilibrium thermal gradients, but this analysis was unsuccessful. The reported data from the heat flow measurements are thermal gradients between adjacent thermistors. For a 4-thermistor penetration with all 4 thermistors operational, the dataset provides thermal gradient values between thermistors 1 and 2, 2 and 3, and 3 and 4. If one thermistor were not functioning (for example, thermistor #2), the reported gradients would be between thermistors 1 and 3 and 3 and 4. Thermal conductivity values were measured on the laboratory benchtop on recovered sediment cores using needle probes. The reported values correspond to core sections between each of the working thermistors. For example, if a gradient is reported for the interval between thermistors 2 and 3, then the dataset gives a corresponding thermal conductivity determination in that interval from the corresponding core. The original thermal conductivity data have been lost, but it is suspected that far more thermal conductivity measurements were completed than are compiled or averaged to generate the values in the dataset. Ruppel and others (2019)--see cross-reference-- analyzes some of the thermal conductivity data in this dataset. Heat flow was calculated by multiplying average thermal gradient and average thermal conductivity. Uncertainties are reported on a subset of the values as a percentage of the heat flow. A maximum heat flow uncertainty is also provided by for heat flow values to which a percentage deviation was assigned. Process date likely spanned the duration of the experiment and is reported below as the last day of 1974, which is the approximate date of the USGS report provided in Lachenbruch and others (2019)--see cross-reference Source_Used_Citation_Abbreviation: Lachenbruch and others (2019)--see cross-reference Process_Date: 19741231 Process_Step: Process_Description: This process step details how the original table was digitized and quality checked. The original table was available only as a PDF scan of Table 2 from Lachenbruch and others (2019). In 2016, Carolyn Ruppel manually keyed most of this table. Subsequently, technical staff (B. Clark and M. Arsenault) at the USGS Woods Hole Coastal and Marine Science Center conducted optical character recognition on parts of the scanned file. The two inputs were combined, and then Deborah Hutchinson conducted quality control on the resulting table. This process identified entries that were partially illegible in the original PDF scan of the report, positions that had been improperly keyed, and one position (station FL-352) that did not plot on the T-3 navigation track obtained through independent means and released with this dataset as "T-3 Ice Island One Hour Navigation: May 14, 1962 to September 15, 1974." Values were corrected in the table based on this analysis. It is expected that some errors likely remain in the transfer of the original PDF scan to the digital data file. It is not believed that any of the possible errors affect the subsequent outcome or analysis in any significant way. Process_Date: 2019 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Carolyn Ruppel Contact_Position: Research Geophysicist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: Massachusetts Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: 508-548-8700 x2263 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: cruppel@usgs.gov Process_Step: Process_Description: Original data were averaged, converted, and updated: Latitudes and longitudes were transformed from degree-minute to decimal degree format. Average thermal gradients were determined by averaging reported interval thermal gradients over the number of interval thermal gradients per station. Average thermal conductivity was determined in the same manner using the interval thermal conductivities. Heat flow was converted from Heat Flow Units (HFU) to modern SI units (mW/m^2) by multiplication by the factor of 41.8 mW/m^2 per HFU. The reported maximum deviation of heat flow measurements was similarly converted to HFU. Uncertainties expressed as a percentage were multiplied by the converted (SI units) heat flow to generate an error bar for use in plotting. Where percentage uncertainties were not reported, a value of 10% was adopted to generate the appropriate error bar. The heat flow value was divided by the average gradient to generate an inferred thermal conductivity used by the original reference (Lachenbruch and others, 2019--see cross-reference). Process_Date: 2019 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Carolyn Ruppel Contact_Position: Research Geophysicist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: Massachusetts Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: 508-548-8700 x2263 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: cruppel@usgs.gov Process_Step: Process_Description: Using Esri ArcGIS 10.2, the latitude and longitude of the heat flow stations were merged with the Arctic Ocean physiographic province polygons from Jakobsson, M., Hypsometry and volume of the Arctic Ocean and its constituent seas, Geochem. Geophys. Geosyst., 3(1), doi:10.1029/2001GC000302, 2002 and a split added between Alpha and Mendeleev Ridges. The polygon shapefiles were provided by Martin Jakobsson to Carolyn Ruppel. This produced a mapping of physiographic province for each heat flow station. In addition, the positions of the heat flow stations were merged with surficial geology from Boggild, K., D. C. Mosher, C. Gebhardt, M. Jakobsson, L. A. Mayer, K. Hogan, and D. Dove (2018), Surficial geology of the Amerasian Basin from subbottom profiler data, Open File Rep. 8465, Geological Survey of Canada, Ottawa, Canada. The surficial geology GIS was provided to the U.S. Geological Survey by David Mosher, co-author on the cross-referenced Journal of Geophysical Research (Ruppel and others, 2019) paper. Dates were added to the dataset first by using known dates of piston cores retrieved from the Arctic Ocean simultaneously with the acquisition of the heat flow data. The dates are given in the NCEI dataset from University of Wisconsin (2016)--see cross-reference. All successful heat flow stations were presumed to have yielded piston cores since thermal conductivity data are reported for all stations. However, not all the cores may have been sent to University of Wisconsin and are therefore not in the database. When core dates were missing, ArcGIS 10.2 was used to find the date on which the T-3 drift path was closest to a particular heat flow station using the 1-hour navigation provided as part of this release in "T-3 Ice Island One Hour Navigation: May 14, 1962 to September 15, 1974." This method assumes that the position recorded for the heat flow station was where the heat flow was actually measured in the seafloor. However, the position could be recorded when the corer entered the water, and the heat flow station actually recorded when it penetrates the bottom, up to hours later. Also note that this method of merging time-stamped navigation with the positional information for the heat flow data assumes that the heat flow probe entered the seafloor vertically beneath the location of the surface infrastructure on T-3 Ice Island. In modern heat flow measurements, the heat flow probe is only rarely directly beneath the vessel when heat flow is recorded. For stations at which neither method for assigning dates was possible, the date was interpolated based on known dates of preceding/subsequent stations. The lengths of cores recovered at each station were added to the file using information from the University of Wisconsin (2016) NCEI release and from a data file provided by Dr. Dennis Darby of Old Dominion University. Process_Date: 2019 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Carolyn Ruppel Contact_Position: Research Geophysicist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: Massachusetts Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: 508-548-8700 x2263 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: cruppel@usgs.gov Process_Step: Process_Description: Text data flags were added as columns in the Excel file to replace color coding used in the working copy of the enhanced data file. Source_Used_Citation_Abbreviation: T3EnhancedHeatFlow.xlsx Process_Date: 20190621 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Carolyn Ruppel Contact_Position: Research Geophysicist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: Massachusetts Postal_Code: 02543-1598 Country: USA Contact_Voice_Telephone: 508-548-8700 x2263 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: cruppel@usgs.gov Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20200806 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.001 Longitude_Resolution: 0.001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.978698214 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: Not known, but likely was water's surface below the ice. Depth_Resolution: 0.1 Depth_Distance_Units: meters Depth_Encoding_Method: attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: T3EnhancedHeatFlow.xlsx Entity_Type_Definition: Excel 2013 Worksheet Entity_Type_Definition_Source: Producer Defined Attribute: Attribute_Label: Station Attribute_Definition: Heat flow station (ordinal number), usually referred to in T-3 literature as "FL-" then station number. Station numbers are non-sequential where heat flow penetration failed (no data obtained). Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2 Range_Domain_Maximum: 584 Attribute: Attribute_Label: Date Attribute_Definition: Probable date of the heat flow measurement in format YYYYMMDD, where YYYY denotes 4 digits for year, MM denotes two digits for month, and DD denotes two digits for day. See process step 4 for information about determination of the date. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 19630423 Range_Domain_Maximum: 19731113 Attribute: Attribute_Label: Date Flag Attribute_Definition: Flag indicating the origin of the probable date in the previous column. "c" indicates that the date is from a database of piston cores (University of Wisconsin, 2016--see cross-reference). When a core was not obtained at the heat flow station but the flag is "c", the date could be pinned with certainty due to known dates at adjacent heat flow stations. "g" indicates that the date was derived by merging the positional information with the T-3 navigation file. "i" indicates that the date was inferred based on other information. For station FL-2, the date is consistent with the T-3 navigation track but is several months before FL-3, so may not be correct. The date for FL-476 was inferred based on known dates of cores at adjacent stations. There is a large time gap between FL-476 and FL-483. FL-479 was arbitrarily assigned to 19700101 since no other information about the date could be inferred given the high density of measurements on this part of Alpha Ridge during this period. Refer to process step 4. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Unrepresentable_Domain: Character set (text). Attribute: Attribute_Label: Latitude (degree) Attribute_Definition: Decimal Degrees of north latitude for heat flow penetration Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 75.371 Range_Domain_Maximum: 86.057 Attribute_Units_of_Measure: decimal degree Attribute_Measurement_Resolution: 0.001 Attribute: Attribute_Label: Longitude (degree) Attribute_Definition: Decimal Degrees of west longitude for heat flow penetration Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -176.703 Range_Domain_Maximum: -78.750 Attribute_Units_of_Measure: decimal degree Attribute_Measurement_Resolution: 0.001 Attribute: Attribute_Label: Water depth (m) Attribute_Definition: water depth in meters at location of heat flow penetration, believed to be measured based on wire-out Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1066 Range_Domain_Maximum: 3818 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 1 Attribute: Attribute_Label: Physiographic province from Jakobsson Attribute_Definition: Physiographic province in which the heat flow station is located based on Jakobsson, M., Hypsometry and volume of the Arctic Ocean and its constituent seas, Geochem. Geophys. Geosyst., 3( 1), doi:10.1029/2001GC000302, 2002. A split was added between Alpha and Mendeleev Ridges and the Greenland-Canada Rise and Slope were combined. Only values of "Alpha Ridge," "Canada Basin," "Mendeleev Ridge," "Nautilus Basin", and "Greenland-Canada Rise/Slope" were used. The submarine highlands within Nautilus Basin were coded as "Nautilus Basin." FL-104 is at the edge of Mendeleev Ridge on the "Chukchi Perched Rise" and is coded as "Mendeleev Ridge." FL-549 and FL-551 are near the boundary with Alpha Ridge polygon and were coded as "Alpha Ridge." FL-550 was coded as "Greenland-Canada Rise/Slope." Refer to process step 4. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Unrepresentable_Domain: Character set (text). Attribute: Attribute_Label: Surficial Geology from Boggild Attribute_Definition: Surficial seafloor geology at heat flow station from the data in Boggild, K., D. C. Mosher, C. Gebhardt, M. Jakobsson, L. A. Mayer, K. Hogan, and D. Dove (2018), Surficial geology of the Amerasian Basin from subbottom profiler data, Open File Rep. 8465, Geological Survey of Canada, Ottawa, Canada. Refer to process step 4. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Unrepresentable_Domain: Character set (text). Attribute: Attribute_Label: Core length (m) Attribute_Definition: Length of the piston core recovered during the heat flow penetration from University of Wisconsin NCEI data release (2016) and data provided by Dennis Darby. Values greater than ~3.7 meters indicate overpenetration (weight stand likely buried in the seafloor) of the corer, which had maximum length of 3.66 m. See process step 4. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.76 Range_Domain_Maximum: 5.54 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: 1-2 Gradient (milliC/m) Attribute_Definition: Thermal gradient in milliCelsius per meter between thermistors 1 and 2, with 1 being the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 24.1 Range_Domain_Maximum: 74.5 Attribute_Units_of_Measure: milliCelsius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: 1-3 Gradient (milliC/m) Attribute_Definition: Thermal gradient in milliCelsius per meter between thermistors 1 and 3, with 1 being the deepest penetrating thermistor. This gradient is used when thermistor 2 is malfunctioning. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 26.4 Range_Domain_Maximum: 75.5 Attribute_Units_of_Measure: milliCelsius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: 2-3 Gradient (milliC/m) Attribute_Definition: Thermal gradient in milliCelsius per meter between thermistors 2 and 3, with 1 being the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 6.9 Range_Domain_Maximum: 109.0 Attribute_Units_of_Measure: milliCelsius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: 2-4 Gradient (milliC/m) Attribute_Definition: Thermal gradient in milliCelsius per meter between thermistors 2 and 4, with 1 being the deepest penetrating thermistor. This gradient is used when thermistor 3 is malfunctioning. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 30.0 Range_Domain_Maximum: 62.7 Attribute_Units_of_Measure: milliCelsius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: 3-4 Gradient (milliC/m) Attribute_Definition: Thermal gradient in milliCelsius per meter between thermistors 3 and 4, with 1 being the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 26.4 Range_Domain_Maximum: 104.4 Attribute_Units_of_Measure: milliCelsius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: 3-5 Gradient (milliC/m) Attribute_Definition: Thermal gradient in milliCelsius per meter between thermistors 3 and 5, with 1 being the deepest penetrating thermistor. This gradient is used when thermistor 4 is malfunctioning. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 34.9 Range_Domain_Maximum: 62.9 Attribute_Units_of_Measure: milliCelcius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: 4-5 Gradient (milliC/m) Attribute_Definition: Thermal gradient in milliCelsius per meter between thermistors 4 and 5, with 1 being the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 47.4 Range_Domain_Maximum: 82.9 Attribute_Units_of_Measure: milliCelsius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: 1-2 Conductivity (mcal/(cm-s-C)) Attribute_Definition: Thermal conductivity in millicalorie per (centimeter-second-degree Celsius) measured on the benchtop (not in the sea floor) in the sediment core section recovered between thermistors 1 and 2. Thermistor 1 is the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.94 Range_Domain_Maximum: 3.60 Attribute_Units_of_Measure: millicalorie per (centimeter-second-degree Celsius) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: 1-3 Conductivity (mcal/(cm-s-C)) Attribute_Definition: Thermal conductivity in millicalorie per (centimeter-second-degree Celsius) measured on the benchtop (not in the seafloor) in the sediment core section recovered between thermistors 1 and 3. Thermistor 1 is the deepest penetrating thermistor. Only used when Thermistor 2 was malfunctioning.(empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.37 Range_Domain_Maximum: 3.07 Attribute_Units_of_Measure: millicalorie per (centimeter-second-degree Celsius) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: 2-3 Conductivity (mcal/(cm-s-C)) Attribute_Definition: Thermal conductivity in millicalorie per (centimeter-second-degree Celsius) measured on the benchtop (not in the seafloor) in the sediment core section recovered between thermistors 2 and 3. Thermistor 1 is the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.58 Range_Domain_Maximum: 3.49 Attribute_Units_of_Measure: millicalorie per (centimeter-second-degree Celsius) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: 2-4 Conductivity (mcal/(cm-s-C)) Attribute_Definition: Thermal conductivity in millicalorie per (centimeter-second-degree Celsius) measured on the benchtop (not in the seafloor) in the sediment core section recovered between thermistors 2 and 4. Thermistor 1 is the deepest penetrating thermistor. Column only used when Thermistor 3 was malfunctioning. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.14 Range_Domain_Maximum: 3.3 Attribute_Units_of_Measure: millicalorie per (centimeter-second-degree Celsius) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: 3-4 Conductivity (mcal/(cm-s-C)) Attribute_Definition: Thermal conductivity in millicalorie per (centimeter-second-degree Celsius) measured on the benchtop (not in the seafloor) in the sediment core section recovered between thermistors 3 and 4. Thermistor 1 is the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.13 Range_Domain_Maximum: 3.41 Attribute_Units_of_Measure: millicalorie per (centimeter-second-degree Celsius) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: 3-5 Conductivity (mcal/(cm-s-C)) Attribute_Definition: Thermal conductivity in millicalorie per (centimeter-second-degree Celsius) measured on the benchtop (not in the seafloor) in the sediment core section recovered between thermistors 3 and 5. Thermistor 1 is the deepest penetrating thermistor. Column only used when Thermistor 4 was malfunctioning. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.79 Range_Domain_Maximum: 3.22 Attribute_Units_of_Measure: millicalorie per (centimeter-second-degree Celsius) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: 4-5 Conductivity (mcal/(cm-s-C)) Attribute_Definition: Thermal conductivity in millicalorie per (centimeter-second-degree Celsius) measured on the benchtop (not in the seafloor) in the sediment core section recovered between thermistors 4 and 5. Thermistor 1 is the deepest penetrating thermistor. (empty cell) for no value. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.76 Range_Domain_Maximum: 3.56 Attribute_Units_of_Measure: millicalorie per (centimeter-second-degree Celsius) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Heat flow (HFU) Attribute_Definition: Heat flow in heat flow units (HFU) calculated by taking the product of the average thermal gradient and average thermal conductivity; 1 HFU = 41.8 milliWatt/m^2. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.71 Range_Domain_Maximum: 2.86 Attribute_Units_of_Measure: Heat Flow Units Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Average % Deviation Attribute_Definition: Percentage uncertainty in heat flow measurement (empty cell means no value reported) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.15 Range_Domain_Maximum: 39.35 Attribute_Units_of_Measure: percentage Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Maximum Heat Flow Deviation (HFU) Attribute_Definition: Maximum uncertainty in heat flow value in heat flow units (HFU). 1 HFU = 41.8 milliWatts/m^2. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: empty cell Enumerated_Domain_Value_Definition: No average percentage deviation given for heat flow measurement and therefore no absolute value of heat flow deviation Enumerated_Domain_Value_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.01 Range_Domain_Maximum: 1.8 Attribute_Units_of_Measure: HFU Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Average thermal gradient (milliC/m) Attribute_Definition: Average of interval thermal gradient values reported in columns labelled with thermistor numbers followed by "gradient." Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 26.7 Range_Domain_Maximum: 106.7 Attribute_Units_of_Measure: milliCelsius per meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: Calculated Thermal Conductivity (W/(m-K)) Attribute_Definition: Average of thermal conductivity values reported in columns labelled thermistor numbers followed by "conductivity," converted to SI units. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.66 Range_Domain_Maximum: 1.46 Attribute_Units_of_Measure: Watts per (meter-Kelvin) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Inferred Thermal Conductivity (W/(m-K)) Attribute_Definition: Thermal conductivity value determined by dividing the reported heat flow in SI units by the average thermal gradient. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.66 Range_Domain_Maximum: 1.89 Attribute_Units_of_Measure: Watts per (meter-Kelvin) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Heat flow Converted (mW/m^2) Attribute_Definition: Conversion of heat flow from heat flow units (HFU) to SI units (mW/m^2) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 29.7 Range_Domain_Maximum: 119.6 Attribute_Units_of_Measure: milliWatts per cubic meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: Max. Heat Flow Deviation Converted (mW/m^2) Attribute_Definition: Maximum uncertainty in heat flow value converted from heat flow units (HFU) to SI units (mW/m^2). 1 HFU = 41.8 milliWatts/m^2. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0.0 Enumerated_Domain_Value_Definition: No absolute maximum heat flow deviation Enumerated_Domain_Value_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.418 Range_Domain_Maximum: 75.2 Attribute_Units_of_Measure: milliWatts per square meter Attribute_Measurement_Resolution: 0.1 Attribute: Attribute_Label: Uncertainty flag Attribute_Definition: Flag indicating whether original dataset provided an uncertainty for this heat flow measurement. "*" indicates none was provided. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Unrepresentable_Domain: Character set (text). Attribute: Attribute_Label: Heat Flow Error Bar (mW/m^2) Attribute_Definition: Percentage deviation multiplied by heat flow value in SI units. Where no uncertainty is given, an uncertainty of 10% is provided. The resulting error bars are assumed to be both the plus and minus value for each heat flow determination. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.1 Range_Domain_Maximum: 27.3 Attribute_Units_of_Measure: milliWatts per square meter Attribute_Measurement_Resolution: 0.1 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical address Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: The dataset contains the data in both Excel XLSX format and CSV format (T3EnhancedHeatFlowTable.xlsx T3EnhancedHeatFlowTable.csv), browse graphic of data locations (T3enhancedheatflowgraphic.jpg), plotting information (USGST3_RelativeThermalGradientPlots.pdf) and images of the thermal gradients measured at each heat flow station (T3Gradients2_75.jpg, T3Gradients76_192.jpg, T3Gradients196_279.jpg, T3Gradients284_354.jpg, T3Gradients355_427.jpg, T3Gradients429_566.jpg, and T3Gradients567_584.jpg), and CSDGM metadata in XML, TXT, and HTML formats. Distribution_Liability: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: XLXS Format_Version_Number: Microsoft Excel version 2013 Format_Information_Content: The dataset contains the XLSX and CSV format of the data, browse graphics and associated FGDC CSDGM metadata. Transfer_Size: 1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/5d10eb42e4b0941bde550210 Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5d10eb42e4b0941bde550210 Network_Resource_Name: https://doi.org/10.5066/P97EPU2F Access_Instructions: The first link downloads all the data on the landing page and provides them in a zip file, the second link goes to the dataset landing page where files can be downloaded individually, and the third link goes to the data release main landing page. Digital_Form: Digital_Transfer_Information: Format_Name: CSV Format_Version_Number: Microsoft Excel version 2013 Format_Specification: Comma-Separated Values exported from Excel Format_Information_Content: The dataset contains the XLSX and CSV format of the data, browse graphics and associated FGDC CSDGM metadata. Transfer_Size: 1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/5d10eb42e4b0941bde550210 Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5d10eb42e4b0941bde550210 Network_Resource_Name: https://doi.org/10.5066/P97EPU2F Access_Instructions: The first link downloads all the data on the landing page and provides them in a zip file, the second link goes to the dataset landing page where files can be downloaded individually, and the third link goes to the data release main landing page. Fees: None Metadata_Reference_Information: Metadata_Date: 20200806 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Carolyn Ruppel Contact_Organization: U.S. Geological Survey, Northeast Region Contact_Position: Research Geophysicist Contact_Address: Address_Type: mailing address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: United States Contact_Voice_Telephone: 508-548-8700 x2339 Contact_Electronic_Mail_Address: cruppel@usgs.gov Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998