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/samuel_p._lee/l1281np/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, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity L-12-81-NP in North Pacific Ocean from 09/19/1981 to 10/05/1981, http://walrus.wr.usgs.gov/infobank/l/l1281np/html/l-12-81-np.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/l/l1281np/html/l-12-81-np.bath.html, http://walrus.wr.usgs.gov/infobank/l/l1281np/html/l-12-81-np.grav.html, and http://walrus.wr.usgs.gov/infobank/l/l1281np/html/l-12-81-np.mag.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. 19810919 19811005 ground condition Complete None planned -130.79816 -122.11925 45.35836 37.50413 USGS Metadata Identifier USGS:d22fa95c-a643-4ef9-804f-5a937ba8f921 ISO 19115 Topic Category geoscientificinformation oceans None Marine Geology Marine Geophysics Marine Gravity Field Marine Magnetic Field Magnetic Anomalies Bathymetry Water Depth Seafloor Topography Data Categories for Marine Planning distributions bathymetry and elevation Marine Realms Information Bank (MRIB) keywords single-beam echo sounder gravimetry magnetic field observations marine geophysics USGS Thesaurus single-beam echo sounder bathymetry measurement bathymetry gravimeter measurement magnetometer measurement marine geophysics Geographic Names Information System (GNIS) North Pacific Ocean Northern Pacific Ocean Pacific Coast, 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 Dennis Mann (Chief Scientist); Don Tompkins (Chief Scientist) 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 (l-12-81-np.053 [SINS]) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198109191714340 198109191830360 >198109191838360 198109192122360 >198109192154560 198109232232550 >198109232250500 198110051416000 >198110051544000 198110051544000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Gravity Data (l-12-81-np.161_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198109191725180 198109220826180 >198109220909300 198109231844000 >198109231856060 198109232037360 >198109232044240 198109250845000 >198109250850300 198109271033180 >198109271038540 198109271928300 >198109271934300 198109290654420 >198109290700000 198109302234480 >198109302240300 198110010653360 >198110010817060 198110020950540 >198110020959000 198110032122420 >198110032128420 198110051533000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Magnetics Data (l-12-81-np.220_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198109230117550 198109231849000 >198109231901080 198109232043200 >198109232049240 198109252254560 >198109261710000 198109271038520 >198109271043560 198109271934040 >198109271939320 198109290659480 >198109290704520 198109291914160 >198109300208200 198110010658400 >198110010822040 198110020956480 >198110021004000 198110021157480 >198110021244440 198110032128040 >198110032133440 198110041533040 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Bathymetry Data (l-12-81-np.305_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Seismic Shots Data (l-12-81-np.420_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198109230303230 198109231406300 >198109231457400 198109231642080 >198109231716450 198109240124070 >198109240217440 198109242010570 >198109242054200 198109250144430 >198109250217490 198109250842500 >198109250944080 198109251331530 >198109251528530 198109252256220 >198109261920160 198109270446280 >198109270551300 198109271528450 >198109271616430 198109280159580 >198109280236080 198109282322590 >198109282329120 198109292255510 >198109292324580 198109300829190 >198109300908240 198110010129550 >198110010200180 198110011822530 >198110011857390 198110020748160 >198110020818040 198110020900310 >198110020907310 198110021127560 >198110021206220 198110031707260 >198110032010530 198110032235350 >198110032307040 198110040904400 >198110040935530 198110041530070 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST Unspecified Unspecified Navigation Data >Converted to time format with year at start. > >10/21/85 KAYE DRS$DATA:[LD81NP.N]LC81NP.053; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > 19960119 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 Gravity Data >10/31/1998 /tiger/l/l1281np/grav/l-12-81-np.161_053 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >10/16/85 BARB DRS$DATA:[LC81NP.G]LC81NP.161; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > >Input was... >Converted to time format with year at start. > >10/21/85 KAYE DRS$DATA:[LD81NP.N]LC81NP.053; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > >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 Magnetics Data >06/20/2012 carolyn l-12-81-np.220_053 > >Reprocessed using subroutines from Susan Macmillan's >IGRF SYNTHESIS PROGRAM http://www.ngdc.noaa.gov/IAGA/vmod/igrf11.f >with IGRF-11 coeffiecients integrated into the source code. >/infobank/programs/mag/magred11/magred11.for >Using geodetic coordinate system (Earth shape approximated by spheriod) >with altitude 0.0 km (for sea level). > >Input was... >10/31/1998 /tiger/l/l1281np/mag/l-12-81-np.200_053 >/bear/programs/edit/automerge/automerge > >Converted to time format with year at start. > >10/07/85 CAROLYN DRS$DATA:[LC81NP.M]LC81NP.200; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >was LC81NP._.MAGSB1 on TAM306 >was LC81NP220.DAT on VAM306 > >Converted to time format with year at start. > >10/21/85 KAYE DRS$DATA:[LD81NP.N]LC81NP.053; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > >time, lat, long, time(sec) to nearest nav fix, data values 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 Bathymetry Data >10/31/1998 /tiger/l/l1281np/bath/l-12-81-np.305_053 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >09/05/85 BECKIE DUA0:[DATA.LC81NP.B]LC81NP.305; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >This file is hand-digetized bathymetry in cor- >rected meters in the Delgado Deep Sea Fan area. > >Input was... >Converted to time format with year at start. > >10/21/85 KAYE DRS$DATA:[LD81NP.N]LC81NP.053; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > >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 North Pacific Ocean Point Point 0.000001 0.000001 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.25722210100002 l1281np.m77t MGD77Tsingle-beam bathymetry, gravity, and magnetics data file for L1281NP 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 19810919 19811005 Year, month, day TIME Time NGDC 0 2359 hours and decimal minutes LAT Latitude World Geodetic System 1984 Geographic Coordinate System 37.50413 45.35836 decimal degrees LON Longitude World Geodetic System 1984 Geographic Coordinate System -130.79813 -122.11998 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 1.0844 6.002 seconds CORR_DEPTH Bathymetry, corrected depth U.S. Geological Survey 804.2 4497.4 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 MAG_TOT Magnetics total field - 1st sensor NGDC 48470 54364 gammas MAG_RES Magnetics residual field field NGDC -3182.7 2867.3 gammas GRA_OBS Observed gravity NGDC 979838.2 980695 milligals EOTVOS EOTVOS correction - E = 7.5 V cos(phi) * sin(alpha) + 0.0042 V*V NGDC -247.6 69.3 milligals FREEAIR Free-air Anomaly = G(observed) minus G(theoretical) NGDC -394.1 207 milligals Bathymetry, gravity, magnetic, and navigation data for U.S. Geological Survey bathymetry survey L1281NP in MGD77T format. 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. 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. 1.9 http://www.ngdc.noaa.gov/mgg/trk/trackline/samuel_p._lee/l1281np/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