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/l384sp/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-3-84-SP in Tonga, Southern Pacific from 04/02/1984 to 05/01/1984, http://walrus.wr.usgs.gov/infobank/l/l384sp/html/l-3-84-sp.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/l384sp/html/l-3-84-sp.bath.html, http://walrus.wr.usgs.gov/infobank/l/l384sp/html/l-3-84-sp.grav.html, and http://walrus.wr.usgs.gov/infobank/l/l384sp/html/l-3-84-sp.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. 19840402 19840501 ground condition Complete None planned 178.39099 -174.74606 -18.13553 -26.50575 USGS Metadata Identifier USGS:87624900-a63e-4848-bfca-097697b79d66 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) Polynesia South Pacific Ocean Southern Pacific Ocean Tonga, Southern Pacific 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 Rick Herzer (Chief Scientist, NZ) 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-3-84-sp.073) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198404020302590 198404020440590 >198404020455390 198404020520000 >198404020550590 198404021249390 >198404021305000 198404041240000 >198404041255000 198404051215000 >198404051230000 198404061400000 >198404061420000 198404130546000 >198404130601000 198404182220000 >198404201732000 198404280558000 >198404280635390 198405010132390 >198405010148000 198405012118000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Gravity Data (l-3-84-sp.162_073) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198404020544000 198404022241000 >198404030556400 198404050302400 >198404050308200 198404060000000 >198404070037200 198404070351000 >198404070358000 198404110216400 >198404110230200 198404120145400 >198404120706200 198404142343400 >198404142349200 198404162332000 >198404162337400 198404182248200 >198404201728200 198404230511000 >198404230524000 198404251738400 >198404251749400 198404251931000 >198404251937000 198404301558400 >198404301624400 198405012034000 >198405012106000 198405012117000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Magnetics Data (l-3-84-sp.223_073) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198404030821400 198404040759000 >198404040805000 198404050304400 >198404050310200 198404050803000 >198404050809000 198404060758400 >198404060804400 198404061829000 >198404061900400 198404070353200 >198404070400000 198404070559000 >198404070604400 198404070810200 >198404070904200 198404071425400 >198404071544400 198404080758400 >198404080804400 198404090802400 >198404090808400 198404100759000 >198404100805000 198404110217400 >198404110232200 198404110811000 >198404110817000 198404120758200 >198404120804200 198404130803200 >198404130809200 198404140759000 >198404140805000 198404142346000 >198404142351200 198404150759000 >198404150805000 198404160343400 >198404160811400 198404161216200 >198404180558400 198404181020400 >198404181303000 198404181332000 >198404181445000 198404181751000 >198404181757000 198404182019200 >198404202120400 198404210801400 >198404212052200 198404212349200 >198404220628200 198404220712200 >198404220809200 198404221320200 >198404221423200 198404221624200 >198404221643200 198404221743200 >198404230124200 198404230626000 >198404230938000 198404231235200 >198404231254200 198404231408200 >198404240637400 198404241318000 >198404250503400 198404250712200 >198404251312200 198404251901400 >198404260742400 198404260810400 >198404260837400 198404261105200 >198404270249000 198404270813400 >198404271322000 198404271555200 >198404271614200 198404271910200 >198404280332000 198404281031400 >198404281304400 198404281402400 >198404281421400 198404290800400 >198404290819400 198404290834400 >198404300000400 198404300118400 >198404300812200 198404301250200 >198404302345400 198405011200200 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Bathymetry Data (l-3-84-sp.331_073) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198404031101180 198404041116540 >198404041127540 198404050300360 >198404050345240 198404060328000 >198404060340480 198404061420000 >198404061430060 198404071352060 >198404071405240 198404071405240 >198404071415540 198404071723300 >198404071745360 198404090926120 >198404090940240 198404090942540 >198404090953000 198404090953000 >198404091005360 198404091434540 >198404091505300 198404101229540 >198404101241120 198404110159540 >198404110212060 198404110938240 >198404110951540 198404111057540 >198404111109480 198404111258480 >198404111309000 198404111334300 >198404111422480 198404111919360 >198404111930060 198404112026180 >198404112040000 198404112230360 >198404112241360 198404112305300 >198404112318000 198404120059480 >198404120138420 198404120415000 >198404120428120 198404120451180 >198404120502120 198404131412240 >198404131452480 198404140502000 >198404140512300 198404150029180 >198404150040120 198404151015180 >198404151026060 198404151229300 >198404151239480 198404151719000 >198404151757000 198404160039420 >198404160050180 198404160428060 >198404160805540 198404161345420 >198404162115540 198404162223060 >198404162233120 198404162256180 >198404162307300 198404162348120 >198404180559180 198404180843240 >198404180854240 198404181020120 >198404181308360 198404181340180 >198404181350360 198404182013240 >198404202019300 198404210111180 >198404210125060 198404210902360 >198404210914540 198404211007120 >198404211021060 198404211050120 >198404211101300 198404211415540 >198404211839480 198404212354000 >198404220632480 198404221651420 >198404230114180 198404231408120 >198404240706060 198404241205180 >198404241233300 198404241308240 >198404250514480 198404251040060 >198404251315180 198404252220060 >198404260750360 198404261338540 >198404261933240 198404270553120 >198404270603240 198404270810420 >198404271403060 198404271529540 >198404271558120 198404271559540 >198404271630480 198404271829480 >198404271843300 198404271909000 >198404280222000 198404280233300 >198404280245360 198404280255180 >198404280347540 198404280404240 >198404280426420 198404281031360 >198404281307180 198404291545480 >198404292359060 198404300106180 >198404300819360 198404301246120 >198404302347180 198405011004300 >198405011018240 198405011159540 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Seismic Shots Data (l-3-84-sp.421_073) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198404031121190 198404031727060 >198404031735040 198404041200350 >198404041213110 198404041459520 >198404041556020 198404050259480 >198404050343060 198404060354240 >198404060404090 198404071745240 >198404071840170 198404081316050 >198404081323100 198404091434590 >198404091505180 198404100337170 >198404100510170 198404101559480 >198404101645150 198404111334580 >198404111415300 198404120059580 >198404120137180 198404130700120 >198404130735590 198404131412440 >198404131450130 198404151229540 >198404151345140 198404151720050 >198404151755140 198404160244550 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST Unspecified Unspecified Navigation Data >Converted to time format with year at start. > >07/12/85 CLINT DRS$DATA:[L384SP.N]L384SP.073; >DRB0:[DRS.FILT]FILTER.EXE; >parameters = 0.0 0.022222222 50 70 > >Input was... >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.072; >DRB0:[DRS.NAV]EOTCSSP.EXE; > >07/08/85 BARB DRS$DATA:[L384SP.N]DESAM.058; >DRB0:[DRS.DSMPL]DESAMTIME.EXE;1 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.058; >DRB0:[DRS.EDIT]MERGEIT.EXE; > >03/15/85 KAYE USR$DISK:[DRS.DATA.L3.N.TEMP]NEWMINSAT.050; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;3 > 20001027 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/l384sp/grav/l-3-84-sp.162_073 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >07/01/88 CAROLYN DRS$DATA:[L384SP.G]L384SP.162; >DUA0:[DRS.PLT.GRAPHED]GRAPHED.EXE; >Free Air Anomaly data >hand edited out spikes in FAA field > >Input was... >Converted to time format with year at start. > >07/12/85 CLINT DRS$DATA:[L384SP.N]L384SP.073; >DRB0:[DRS.FILT]FILTER.EXE; >parameters = 0.0 0.022222222 50 70 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.072; >DRB0:[DRS.NAV]EOTCSSP.EXE; > >07/08/85 BARB DRS$DATA:[L384SP.N]DESAM.058; >DRB0:[DRS.DSMPL]DESAMTIME.EXE;1 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.058; >DRB0:[DRS.EDIT]MERGEIT.EXE; > >03/15/85 KAYE USR$DISK:[DRS.DATA.L3.N.TEMP]NEWMINSAT.050; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;3 > >time, lat, long, time(sec) to nearest nav fix, data values 20001102 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-3-84-sp.223_073 > >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/magred1111/magred1111.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/l384sp/mag/l-3-84-sp.222_073 >/bear/programs/edit/automerge/automerge > >Converted to time format with year at start. > >06/21/88 CAROLYN DRS$DATA:[L384SP.M]L384SP.222; >DUA0:[DRS.PLT]GRAPHED.EXE; >Edited magnetics data > >06/21/88 CAROLYN DRS$DATA:[L384SP.M]L384SP.221; >DUA0:[DRS.NGDC]DESPIKE.EXE; >Edited magnetics data >deleted spikes greater than +/- 3000.0 gammas > >06/21/88 CAROLYN DRS$DATA:[L384SP.M]L384SP.220; >DUA0:[DRS.MAG]MAGRED.EXE;5 >Edited magnetics data >DGRF80 & IGRF85 > >10/20/86 CAROLYN DRS$DATA:[L384SP]L384SP.201; >DUA0:[DRS.REFMT]REFORMAT.EXE;5 >was USR$DISK:[DRS.DATA.L3.M]L384SP.200;1 2-NOV-1984 on DISCO > >07/12/85 CLINT DRS$DATA:[L384SP.N]L384SP.073; >DRB0:[DRS.FILT]FILTER.EXE; >parameters = 0.0 0.022222222 50 70 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.072; >DRB0:[DRS.NAV]EOTCSSP.EXE; > >07/08/85 BARB DRS$DATA:[L384SP.N]DESAM.058; >DRB0:[DRS.DSMPL]DESAMTIME.EXE;1 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.058; >DRB0:[DRS.EDIT]MERGEIT.EXE; > >03/15/85 KAYE USR$DISK:[DRS.DATA.L3.N.TEMP]NEWMINSAT.050; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;3 > >Converted to time format with year at start. > >07/12/85 CLINT DRS$DATA:[L384SP.N]L384SP.073; >DRB0:[DRS.FILT]FILTER.EXE; >parameters = 0.0 0.022222222 50 70 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.072; >DRB0:[DRS.NAV]EOTCSSP.EXE; > >07/08/85 BARB DRS$DATA:[L384SP.N]DESAM.058; >DRB0:[DRS.DSMPL]DESAMTIME.EXE;1 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.058; >DRB0:[DRS.EDIT]MERGEIT.EXE; > >03/15/85 KAYE USR$DISK:[DRS.DATA.L3.N.TEMP]NEWMINSAT.050; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;3 > >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/l384sp/bath/l-3-84-sp.331_073 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >06/23/88 CAROLYN DRS$DATA:[L384SP.B]L384SP.331; >DUA0:[DRS.PLT.GRAPHED]GRAPHED.EXE; >Edited bathymetry data > >05/01/85 BECKIE USR$DISK:[DRS.DATA.L384SP.B]L384SP.330; >DRA1:[DRS.BAT]BATRED.EXE;1 >This is clean hand-digetized bathymetry. > >05/01/85 BECKIE USR$DISK:[DRS.DATA.L384SP.B]L384SP.310; >DRA1:[DRS.REFMT]REFORMAT.EXE;4 >This file contains edited hand-digetized bathy. > >Input was... >Converted to time format with year at start. > >07/12/85 CLINT DRS$DATA:[L384SP.N]L384SP.073; >DRB0:[DRS.FILT]FILTER.EXE; >parameters = 0.0 0.022222222 50 70 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.072; >DRB0:[DRS.NAV]EOTCSSP.EXE; > >07/08/85 BARB DRS$DATA:[L384SP.N]DESAM.058; >DRB0:[DRS.DSMPL]DESAMTIME.EXE;1 > >07/08/85 BARB DRS$DATA:[L384SP.N]L384SP.058; >DRB0:[DRS.EDIT]MERGEIT.EXE; > >03/15/85 KAYE USR$DISK:[DRS.DATA.L3.N.TEMP]NEWMINSAT.050; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;3 > >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 Tonga, Southern Pacific Point Point 0.000001 0.000001 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.25722210100002 l384sp.m77t MGD77T single-beam bathymetry data file for L384SP 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 19840402 19840501 Year, month, day TIME Time NGDC 0 2359.933 hours and decimal minutes LAT Latitude World Geodetic System 1984 Geographic Coordinate System -26.50575 -18.13553 decimal degrees LON Longitude World Geodetic System 1984 Geographic Coordinate System -179.99976 179.99999 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 0.158 13.8 seconds CORR_DEPTH Bathymetry, corrected depth U.S. Geological Survey 188.5 10747.4 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 36667.7 48911.7 gammas MAG_RES Magnetics residual field field NGDC -9038 4267.4 gammas GRA_OBS Observed gravity NGDC 977000 977209.4 milligals EOTVOS EOTVOS correction - E = 7.5 V cos(phi) * sin(alpha) + 0.0042 V*V NGDC -169.7 71 milligals FREEAIR Free-air Anomaly = G(observed) minus G(theoretical) NGDC -352.3 227 milligals LINEID LINE/TRACK/SEGMENT ID NGDC 2 19 Used, for example, to cross reference with seismic data. POINTID SEISMIC SHOT-POINT NUMBER/POINT ID NGDC 41 9081 Used, for example, to cross reference with seismic data. Bathymetry, gravity, magnetic, and navigation data for U.S. Geological Survey bathymetry survey L384SP 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. 4.0 http://www.ngdc.noaa.gov/mgg/trk/trackline/samuel_p._lee/l384sp/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