U.S. Geological Survey Coastal and Marine Geology Program 2013 tab-delimited ASCII text files Menlo Park, CA U.S. Geological Survey http://www.ngdc.noaa.gov/mgg/trk/trackline/growler/g178eg/mgd77/ Wm. Clinton Steele Carolyn H. Degnan Gary B. Deeter Jean A. Riordan 1980 1.0 Digital Document U.S. Geological Survey Open File Report 167 Menlo Park, CA U.S. Geological Survey http://pubs.usgs.gov/of/1989/0167/report.pdf Single-beam bathymetry data along with DGPS navigation data was collected as part of field activity G-1-78-EG in Eastern Gulf of Alaska, Glacier Bay from 09/12/1978 to 09/23/1978, http://walrus.wr.usgs.gov/infobank/g/g178eg/html/g-1-78-eg.meta.html These data are reformatted from space-delimited ASCII text files located in the Coastal and Marine Geology Program (CMGP) InfoBank field activity catalog at http://walrus.wr.usgs.gov/infobank/g/g178eg/html/g-1-78-eg.bath.html 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. 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/ ). 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 Acquistion, 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. 19780912 19780923 ground condition Complete None planned -136.59869 -135.79955 59.05107 58.72551 USGS Metadata Identifier USGS:dd57e21d-0ae9-4ea2-b8f2-3745ab1c0535 ISO 19115 Topic Category geoscientificinformation oceans None Marine Geology Marine Geophysics Bathymetry Water Depth Seafloor Topography Data Categories for Marine Planning distributions bathymetry and elevation Marine Realms Information Bank (MRIB) keywords single-beam echo sounder marine geophysics USGS Thesaurus single-beam echo sounder bathymetry measurement bathymetry marine geophysics Geographic Names Information System (GNIS) AK Eastern Gulf of Alaska Eastern Gulf of Alaska, Glacier Bay Glacier Bay, AK USA None. These data are held in the public domain. This information is not intended for navigational purposes. Read and fully comprehend the metadata prior to data use. Uses of these data should not violate the spatial resolution of the data. Where these data are used in combination with other data of different resolution, the resolution of the combined output will be limited by the lowest resolution of all the data. Acknowledge the U.S. Geological Survey in products derived from these data. Share data products developed using these data with the U.S. Geological Survey.This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.Although this Federal Geographic Data Committee-compliant metadata file is intended to document these data in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. Gregory K. Miller U.S. Geological Survey Physical Scientist mailing and physical

600 4th Street South

St. Petersburg FL 33701 USA (727) 803-8747, ext. 3020 gmiller@usgs.gov Paul Carlson (Chief Scientist, USGS Western Region); Bruce Molnia (Chief Scientist, USGS Western Region) Hittelman, Allen M., Groman, Robert C., Haworth, Richard T., Holcombe, Troy L., McHendrie, Graig, Smith, Stuart M., and Metzger, Dan R. 2010 Boulder, CO National Geophysical Data Center, National Oceanic and Atmospheric Administration 25 p. http://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.pdf 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. 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. Start and end date/times of data >Navigation Data (g-1-78-eg.051 [SINS]) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >197809121522000 197809121745000 >197809121800000 197809121800000 >197809131031000 197809131200000 >197809161539002 197809161800002 >197809170835002 197809170852002 >197809171007002 197809171116002 >197809171127002 197809171154002 >197809171205002 197809171215002 >197809181548002 197809181735002 >197809191035002 197809191250002 >197809191423002 197809191634002 >197809211245002 197809211445002 >197809211637002 197809211807002 >197809220920002 197809220929002 >197809220940002 197809221000002 >197809221130002 197809221218002 >197809221555002 197809221647002 >197809221905002 197809222001002 >197809230930002 197809230945002 >197809231050003 197809231120003 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Bathymetry Data (g-1-78-eg.310_051) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >197809121522000 197809121659160 >197809121706020 197809121706030 >197809121712160 197809121722010 >197809121730050 197809121800000 >197809131031000 197809131200000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST Unspecified Unspecified Navigation Data >Converted to time format with year at start. > >05/08/86 CAROLYN DRS$DATA:[REARIC]G178EG.051; >DRB0:[DRS.REFMT]REFORMAT.EXE;5 >255/1522-256/1200 from Doug Rearic >259/1539-266/1120 was G178EG.050 on DRS210 reformatted by Kaye > 19951206 U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG) Carolyn H. Degnan Geophysicist mailing and physical address

USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive

Santa Cruz CA 95060-5792 USA (831) 460-7452 (831) 427-4748 infobank@octopus.wr.usgs.gov Bathymetry Data >10/31/1998 /tiger/g/g178eg/bath/g-1-78-eg.310_051 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >05/08/86 CAROLYN DRS$DATA:[REARIC]G178EG.310; >DRB0:[DRS.REFMT]REFORMAT.EXE;5 >travel times to SEAFLOOR (depth = travel_time * 750) >from Doug Rearic > >Input was... >Converted to time format with year at start. > >05/08/86 CAROLYN DRS$DATA:[REARIC]G178EG.051; >DRB0:[DRS.REFMT]REFORMAT.EXE;5 >255/1522-256/1200 from Doug Rearic >259/1539-266/1120 was G178EG.050 on DRS210 reformatted by Kaye > >time, lat, long, time(sec) to nearest nav fix, data values 19981031 U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG) Carolyn H. Degnan Geophysicist mailing and physical address

USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive

Santa Cruz CA 95060-5792 USA (831) 460-7452 (831) 427-4748 infobank@octopus.wr.usgs.gov 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. 20120620 U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) Carolyn H. Degnan Geophysicist mailing and physical address

USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive

Santa Cruz CA 95060-5792 USA (831) 460-7452 (831) 427-4748 infobank@octopus.wr.usgs.gov Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. 20170201 U.S. Geological Survey Alan O. Allwardt Contractor -- Information Specialist mailing and physical address

2885 Mission Street

Santa Cruz CA 95060 831-460-7551 831-427-4748 aallwardt@usgs.gov Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 20201019 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Eastern Gulf of Alaska, Glacier Bay Point Point 0.000001 0.000001 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.25722210100002 g178eg.m77t MGD77T single-beam bathymetry data file for G178EG NOAA's National Geophysical Data Center, See Hittelman and others (2010) Cross_Reference section above for details about the MGD77T format and citation information. SURVEY_ID Survey identifier supplied by the contributing organization NGDC This identifier varies in format and is supplied by the contributing organization TIMEZONE Time-zone correction NGDC In our datasets, no correction was applied. All values equal 0. DATE YYYYMMDD NGDC 19780912 19780923 Year, month, day TIME Time NGDC 836 1955 hours and decimal minutes LAT Latitude World Geodetic System 1984 Geographic Coordinate System 58.72552 59.05081 decimal degrees LON Longitude World Geodetic System 1984 Geographic Coordinate System -136.59869 -135.79956 decimal degrees POS_TYPE Indicates how lat/lon was obtained NGDC 1 3 1 = observed fix, 3 = interpolated fix, nil = unspecified BAT_TTIME Bathymetry, 2-way travel time U.S. Geological Survey 0.06 0.572 seconds CORR_DEPTH Bathymetry, corrected depth U.S. Geological Survey 45 423 decimal meters BAT_CPCO Bathymetric Correction code - details the procedure used for determining the sound velocity correction to depth NGDC 63 63 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 BAT_TYPCO Bathymetry type code - indicates how the bathymetric value was obtained NGDC 1 3 1 - Observed, 3 - Interpolated (Header Seq. 12), 9 - Unspecified Bathymetry and navigation data for U.S. Geological Survey bathymetry survey G178EG in MGD77T format. Attributes are obtained from MGD77T data files created from the navigation 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. U.S. Geological Survey mailing and physical address

345 Middlefield Road MS 999

Menlo Park CA 94025 USA (650) 329-5078 (650) 329-5190 Downloadable Data 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. MGD77t 10 MGD77 tab-delimited ASCII text files. .031 http://www.ngdc.noaa.gov/mgg/trk/trackline/growler/g178eg/mgd77/ Data are available for download on the World Wide Web (WWW). None 20201019 Gregory K. Miller U.S. Geological Survey Physical Scientist mailing and physical address

U.S. Geological Survey, 600 Fourth Street South

St. Petersburg FL 33701 USA (727) 803-8747, ext. 3020 gmiller@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998