Metadata: Identification_Information: Citation: Citation_Information: Originator: Carolyn H. Degnan Publication_Date: 2013 Title: g176ar.m77t - MGD77 data file for Geophysical data from field activity G-1-76-AR in Arctic from 09/07/1976 to 10/02/1976 Geospatial_Data_Presentation_Form: tab-delimited ASCII text files Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Online_Linkage: https://www.ngdc.noaa.gov/mgg/trk/trackline/glacier/g176ar/mgd77/ Larger_Work_Citation: Citation_Information: Originator: Wm. Clinton Steele Originator: Carolyn H. Degnan Originator: Gary B. Deeter Originator: Jean A. Riordan Publication_Date: 1980 Title: DESCRIPTION OF MARINE GEOPHYSICAL DATA COLLECTED BY THE U.S. GEOLOGICAL SURVEY AND HOW TO OBTAIN IT Edition: 1.0 Geospatial_Data_Presentation_Form: Digital Document Series_Information: Series_Name: Open-File Report Issue_Identification: 89-167 Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.3133/ofr89167 Online_Linkage: https://pubs.usgs.gov/of/1989/0167/report.pdf Description: Abstract: Single-beam bathymetry data along with DGPS navigation data was collected as part of field activity G-1-76-AR in Arctic from 09/07/1976 to 10/02/1976. The geophysical source was a Knudsen 12 kHz 320B/R echosounder. These data are reformatted from space-delimited ASCII text files, located in the former Coastal and Marine Geology Program (CMGP) InfoBank field activity catalog, into MGD77T format provided by the NOAA's National Geophysical Data Center (NGDC). The MGD77T format includes a header (documentation) file (.h77t) and a data file (.m77t). More information regarding this format can be found in the publication listed in the Cross_reference section of this metadata file. For additional information about USGS Field Activity G-1-76-AR go to https://cmgds.marine.usgs.gov/fan_info.php?fan=G176AR. Purpose: These data and information are intended for science researchers, students, policy makers, and general public. These data are not to be used for navigation purposes. The data are reformatted into MGD77T standard format for inclusion into NOAA's NGDC geophysical database. From there the data will be made available to GeoMapApp (http://www.geomapapp.org/) and Virtual Ocean (http://www.virtualocean.org/) Earth-browsing software. Access to the data is also provided via the USGS Coastal and Marine Geoscience Data System (http://cmgds.marine.usgs.gov/). Supplemental_Information: The navigation data are digitally collected using a Satellite Integrated Navigation (SINS) system. The system is a space-based satellite navigation maintained by the United States government and is accessible using a satellite receiver. This system provides navigational accuracy of approximately 200 m.The Data Acquisition, Processing, and Storage (DAPS) group performs a number of processing steps to the navigation data once it is collected which can vary by cruise. These steps are outlined within the header information in each individual digital navigation (.05x) space-delimited ASCII data file. The header information rows are indicated by lines beginning with the character "!". There is no information on how the single-beam bathymetry, gravity, and magnetic data were collected. For each data gathering cruise leg, the available data in the following categories are forwarded to NGDC: navigation, gravity, magnetics, bathymetry, and seismic shot points. The available data for each cruise leg are re-formatted and combined into the Marine Geophysical Data Exchange Format (MGD77) and into the internal NGDC SEIS-NAV format by USGS using several USGS developed FORTRAN programs.The FORTRAN programs sample the navigation to every integer minute of the cruise. When necessary, the latitudes and longitudes are linearly interpolated. If the time between the actual navigation fixes exceeds five minutes, no data are included in the MGD77 file.To build the MGD77 file, gravity, magnetics, and bathymetry are added to this sampled navigation. When necessary, gravity, magnetics, and bathymetry data are linearly interpolated if the time between the actual data samples does not exceed five minutes. If a time gap exceeds this, the data are not reported.The navigation data are merged with the seismic shot point data in a SEIS- NAV format file. For this file, navigation data are interpolated for each shot point. Both types of files are written to magnetic tape and sent to NGDC. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19760907 Ending_Date: 19761002 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -168.97333 East_Bounding_Coordinate: -151.00000 North_Bounding_Coordinate: 73.12067 South_Bounding_Coordinate: 66.68333 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:03772b85-4e29-42d2-830b-4940acda2528 Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificinformation Theme_Keyword: oceans 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: Pacific Coastal and Marine Science Center Theme_Keyword: PCMSC Theme_Keyword: Water Depth Theme_Keyword: Seafloor Topography Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: distributions Theme_Keyword: bathymetry and elevation Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords Theme_Keyword: single-beam echo sounder Theme_Keyword: marine geophysics Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: single-beam echo sounder Theme_Keyword: bathymetry measurement Theme_Keyword: bathymetry Theme_Keyword: marine geophysics Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: State of Alaska Place_Keyword: Arctic Place_Keyword: Arctic Ocean Access_Constraints: None Use_Constraints: USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator of the dataset and in products derived from these data. This information is not intended for navigation purposes. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: US Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Data_Set_Credit: Art Grantz (Chief Scientist, USGS Western Region) Cross_Reference: Citation_Information: Originator: Hittelman, Allen M., Groman, Robert C., Haworth, Richard T., Holcombe, Troy L., McHendrie, Graig, Smith, Stuart M., and Metzger, Dan R. Publication_Date: 2010 Title: The marine geophysical data exchange format - MGD77 / MGD77T Publication_Information: Publication_Place: Boulder, CO Publisher: National Geophysical Data Center, National Oceanic and Atmospheric Administration Other_Citation_Details: 25 p. Online_Linkage: https://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.pdf Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The validity or accuracy of bathymetry and navigation data is highly qualitative and depends on equipment and operating condition variables. Data quality is unknown, MGD77T files were formatted from InfoBank files identified as best available version. Logical_Consistency_Report: This data set is from one field activity with unknown instrument calibrations. Processed bathymetric depths were spot checked based on latitude and longitude against the Global Multi-Resolution Topography (GMRT) grid within GeoMapApp to ensure reasonable values. Completeness_Report: Start and end date/times of data >Navigation Data (g-1-76-ar.050 [SINS]) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >197609071612000 197609200130000 >197609200310000 197609201328000 >197609201514000 197609201918000 >197609202102000 197609211112000 >197609211234000 197609212107000 >197609242200000 197609250602000 >197609250902000 197609250902000 >197609251102000 197609251102000 >197609251228000 197609251310000 >197609251442000 197609251500000 >197609251630000 197609260456000 >197609260620000 197609260950000 >197609261140000 197609261406000 >197609261530000 197609270233000 >197609270410000 197609270732000 >197609270854000 197609271040000 >197609271224000 197609271940000 >197609272128000 197609280458000 >197609280642000 197609281848000 >197609282032000 197609290700000 >197609290854000 197609291746000 >197609291936000 197610011000000 >197610011130000 197610021038000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Bathymetry Data (g-1-76-ar.301_050) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >197609121230000 197609121320000 >197609121415000 197609121445000 >197609121500000 197609121540000 >197609121600000 197609121620000 >197609121700000 197609122110000 >197609130122000 197609130352000 >197609130430000 197609131830000 >197609131848000 197609132133000 >197609132151000 197609132233000 >197609132245000 197609140820000 >197609140900000 197609141036000 >197609141140000 197609142009000 >197609142115000 197609142215000 >197609142247000 197609150045000 >197609150300000 197609150715000 >197609150730000 197609150839000 >197609150850000 197609151600000 >197609151722000 197609151746000 >197609151830000 197609162030000 >197609162100000 197609162209000 >197609162230000 197609162323000 >197609162335000 197609170607000 >197609170619000 197609172041000 >197609182100000 197609182115000 >197609190832000 197609190928000 >197609190954000 197609191021000 >197609191032000 197609191140000 >197609191152000 197609191815000 >197609192000000 197609200450000 >197609200515000 197609200655000 >197609200800000 197609202010000 >197609202035000 197609220900000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Unspecified Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Unspecified Lineage: Process_Step: Process_Description: Navigation Data >Converted to time format with year at start. > >01/29/86 KAYE DISK$USERDISK:[KAYE.MISCLEE]G176AR.050; >DRB0:[DRS.REFMT]REFORMAT.EXE;5 >Original filename is g176ar.sdrcx1._. > Process_Date: 19951206 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Carolyn H. Degnan Contact_Position: Geophysicist Contact_Address: Address_Type: mailing and physical address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: USA Contact_Voice_Telephone: (831) 460-7452 Contact_Facsimile_Telephone: (831) 427-4748 Contact_Electronic_Mail_Address: infobank@octopus.wr.usgs.gov Process_Step: Process_Description: Bathymetry Data >10/31/1998 /tiger/g/g176ar/bath/g-1-76-ar.301_050 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >02/11/86 BECKIE DISK$USERDISK:[BECKIE.TEMP]G176AR.301; >DRB0:[DRS.REFMT]REFORMAT.EXE;5 >I do not know how this file was initially generated. >I believe none of the depths should be over 500 meters >and many should be less than 100 meters. > >Input was... >Converted to time format with year at start. > >01/29/86 KAYE DISK$USERDISK:[KAYE.MISCLEE]G176AR.050; >DRB0:[DRS.REFMT]REFORMAT.EXE;5 >Original filename is g176ar.sdrcx1._. > >time, lat, long, time(sec) to nearest nav fix, data values Process_Date: 19981031 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Carolyn H. Degnan Contact_Position: Geophysicist Contact_Address: Address_Type: mailing and physical address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: USA Contact_Voice_Telephone: (831) 460-7452 Contact_Facsimile_Telephone: (831) 427-4748 Contact_Electronic_Mail_Address: infobank@octopus.wr.usgs.gov Process_Step: Process_Description: MGD77 file creation - The available data for each cruise leg are re-formatted and combined into the Marine Geophysical Data Exchange Format (MGD77) and into the internal NGDC SEIS-NAV format by USGS using several USGS developed FORTRAN programs.The FORTRAN programs sample the navigation to every integer minute of the cruise. When necessary, the latitudes and longitudes are linearly interpolated. If the time between the actual navigation fixes exceeds five minutes, no data are included in the MGD77 file.To build the MGD77 file, gravity, magnetics, and bathymetry are added to this sampled navigation. When necessary, gravity, magnetics, and bathymetry data are linearly interpolated if the time between the actual data samples does not exceed five minutes. If a time gap exceeds this, the data are not reported.The navigation data are merged with the seismic shot point data in a SEIS- NAV format file. For this file, navigation data are interpolated for each shot point. Both types of files are written to magnetic tape and sent to NGDC. Process_Date: 20120620 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Carolyn H. Degnan Contact_Position: Geophysicist Contact_Address: Address_Type: mailing and physical address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: USA Contact_Voice_Telephone: (831) 460-7452 Contact_Facsimile_Telephone: (831) 427-4748 Contact_Electronic_Mail_Address: infobank@octopus.wr.usgs.gov Process_Step: Process_Description: Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. Process_Date: 20170201 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Alan O. Allwardt Contact_Position: Contractor -- Information Specialist Contact_Address: Address_Type: mailing and physical address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-460-7551 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: aallwardt@usgs.gov Process_Step: Process_Description: Empty xml tags removed and other minor edits performed to comply with FGDC standard. Edits were made to bring the metadata up to current PCMSC standards including adding a doi# link, correcting typos, refining keywords, and using current access and distribution liability statements. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. No data were changed. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version. Process_Date: 20200131 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Susan A. Cochran Contact_Address: Address_Type: mailing and physical address Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-460-7545 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: scochran@usgs.gov Process_Step: Process_Description: Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Process_Date: 20201019 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: Indirect_Spatial_Reference: Arctic Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: D_WGS_1984 Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.25722210100002 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: g176ar.m77t Entity_Type_Definition: MGD77T single-beam bathymetry data file for G176AR Entity_Type_Definition_Source: NOAA's National Geophysical Data Center, See Hittelman and others (2010) Cross_Reference section above for details about the MGD77T format and citation information. Attribute: Attribute_Label: SURVEY_ID Attribute_Definition: Survey identifier supplied by the contributing organization Attribute_Definition_Source: NGDC Attribute_Domain_Values: Unrepresentable_Domain: This identifier varies in format and is supplied by the contributing organization Attribute: Attribute_Label: TIMEZONE Attribute_Definition: Time-zone correction Attribute_Definition_Source: NGDC Attribute_Domain_Values: Unrepresentable_Domain: In our datasets, no correction was applied. All values equal 0. Attribute: Attribute_Label: DATE Attribute_Definition: YYYYMMDD Attribute_Definition_Source: NGDC Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 19760907 Range_Domain_Maximum: 19761002 Attribute_Units_of_Measure: Year, month, day Attribute: Attribute_Label: TIME Attribute_Definition: Time Attribute_Definition_Source: NGDC Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 2359 Attribute_Units_of_Measure: hours and decimal minutes Attribute: Attribute_Label: LAT Attribute_Definition: Latitude Attribute_Definition_Source: World Geodetic System 1984 Geographic Coordinate System Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 66.68333 Range_Domain_Maximum: 73.12067 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: LON Attribute_Definition: Longitude Attribute_Definition_Source: World Geodetic System 1984 Geographic Coordinate System Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -168.97333 Range_Domain_Maximum: -151.00000 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: POS_TYPE Attribute_Definition: Indicates how lat/lon was obtained Attribute_Definition_Source: NGDC Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 3 Attribute_Units_of_Measure: 1 = observed fix, 3 = interpolated fix, nil = unspecified Attribute: Attribute_Label: BAT_TTIME Attribute_Definition: Bathymetry, 2-way travel time Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.081 Range_Domain_Maximum: 3.38 Attribute_Units_of_Measure: seconds Attribute: Attribute_Label: CORR_DEPTH Attribute_Definition: Bathymetry, corrected depth Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 63 Range_Domain_Maximum: 2481 Attribute_Units_of_Measure: decimal meters Attribute: Attribute_Label: BAT_CPCO Attribute_Definition: Bathymetric Correction code - details the procedure used for determining the sound velocity correction to depth Attribute_Definition_Source: NGDC Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 63 Range_Domain_Maximum: 63 Attribute_Units_of_Measure: 01-55 Matthews' Zones with zone , 59 Matthews' Zones, no zone specified, 60 S. Kuwahara Formula, 61 Wilson Formula, 62 Del Grosso Formula, 63 Carter's Tables, 88 Other (see Add. Doc.), 97 Computed using 1500 meters/sec, 98 Unknown if Corrected, 99 Unspecified Attribute: Attribute_Label: BAT_TYPCO Attribute_Definition: Bathymetry type code - indicates how the bathymetric value was obtained Attribute_Definition_Source: NGDC Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 3 Attribute_Units_of_Measure: 1 - Observed, 3 - Interpolated (Header Seq. 12), 9 - Unspecified Overview_Description: Entity_and_Attribute_Overview: Bathymetry and navigation data for U.S. Geological Survey bathymetry survey G176AR in MGD77T format. Entity_and_Attribute_Detail_Citation: Attributes are obtained from MGD77T data files created from the navigation gravity, magnetic, and bathymetry best files. MGD77T is the standard, defined data format used for geophysical data in the National Geophysical Data Center. See Cross_Reference section above for citation details. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing and physical address Address: 345 Middlefield Road MS 999 City: Menlo Park State_or_Province: CA Postal_Code: 94025 Country: USA Contact_Voice_Telephone: (650) 329-5078 Contact_Facsimile_Telephone: (650) 329-5190 Resource_Description: Downloadable Data 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: MGD77t Format_Version_Number: 10 Format_Specification: MGD77 Format_Information_Content: tab-delimited ASCII text files Transfer_Size: 0.091 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.ngdc.noaa.gov/mgg/trk/trackline/glacier/g176ar/mgd77/ Access_Instructions: Data are available for download on the World Wide Web (WWW). Fees: None Metadata_Reference_Information: Metadata_Date: 20201019 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: US Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998