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/l881wg/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, magnetics, and gravity data along with transit satellite navigation data was collected as part of field activity L-8-81-WG in Western Gulf of Alaska from 07/04/1981 to 07/16/1981, http://walrus.wr.usgs.gov/infobank/l/l881wg/html/l-8-81-wg.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/l881wg/html/l-8-81-wg.bath.html http://walrus.wr.usgs.gov/infobank/l/l881wg/html/l-8-81-wg.grav.html http://walrus.wr.usgs.gov/infobank/l/l881wg/html/l-8-81-wg.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. 19810704 19810716 ground condition Complete None planned -166.53174 -152.04260 57.79134 53.38086 USGS Metadata Identifier USGS:9c1c33c2-068b-4cc1-86da-155074ea9561 ISO 19115 Topic Category geoscientificinformation oceans None Marine Geology Marine Geophysics Single-beam Bathymetry Water Depth Seafloor Topography Marine Seismic Marine Gravity Marine Magnetics 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 none AK Alaska Bering Sea Bering Sea, Alaska 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 Terry Bruns(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-8-81-wg.053 [SINS]) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198107041842200 198107050154000 >198107071354000 198107110742360 >198107110755360 198107140421470 >198107140434250 198107162105000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Gravity Data (l-8-81-wg.151_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198107042014180 198107042015180 >198107042112420 198107042158420 >198107042211420 198107042258420 >198107042311420 198107050128420 >198107061249420 198107061253420 >198107071708180 198107080810300 >198107080825300 198107081045300 >198107081138240 198107081737300 >198107081752300 198107081836300 >198107081907300 198107090055240 >198107090125180 198107090342180 >198107090403180 198107090458180 >198107090514180 198107091518300 >198107091617300 198107091718300 >198107091732300 198107091818300 >198107091836300 198107091853300 >198107091917300 198107092018300 >198107092105300 198107092222300 >198107092245300 198107100021300 >198107100101300 198107100403480 >198107100439480 198107101038480 >198107101045120 198107101742300 >198107101843300 198107110738540 >198107110805540 198107111806300 >198107111830180 198107112054360 >198107112137420 198107112156420 >198107112203300 198107120001300 >198107120031300 198107121244240 >198107121333300 198107130003300 >198107130010060 198107130904300 >198107130910420 198107131322420 >198107131357420 198107131725420 >198107131808060 198107140109180 >198107140135180 198107140309180 >198107140512240 198107140631240 >198107140650240 198107140743240 >198107140815240 198107140925240 >198107141018360 198107141132360 >198107141158540 198107141449060 >198107141457120 198107141553120 >198107141618120 198107141702180 >198107141717180 198107142010240 >198107142038240 198107151700240 >198107151711240 198107152218240 >198107152227180 198107160758180 >198107160834480 198107161747000 >198107161801000 198107162027240 >198107162056240 198107162058240 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Magnetics Data (l-8-81-wg.220_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198107071913400 198107081117120 >198107081142250 198107090101200 >198107090531200 198107101042480 >198107101049120 198107111811160 >198107111834180 198107112201080 >198107112207320 198107130008000 >198107130014040 198107130909080 >198107130914440 198107131730000 >198107131812040 198107141140520 >198107141146560 198107152223210 >198107152231170 198107160259370 >198107160614200 198107160803000 >198107160838480 198107161522240 >198107162015410 198107162015570 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Bathymetry Data (l-8-81-wg.335_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198107081200060 198107081314480 >198107081400000 198107081400000 >198107081429540 198107081430540 >198107081444480 198107081444480 >198107081500000 198107081500000 >198107081516000 198107081516000 >198107081530060 198107081530060 >198107081544420 198107081630000 >198107081640240 198107081647360 >198107081700000 198107081715540 >198107081745000 198107081745000 >198107081800000 198107081802240 >198107081814360 198107081830000 >198107081840420 198107082016360 >198107082029540 198107082046120 >198107082059120 198107082107060 >198107082130000 198107082201120 >198107082223060 198107090107300 >198107090815000 198107090929540 >198107090942180 198107091215360 >198107091230060 198107091230060 >198107091245000 198107091245000 >198107091300420 198107091304120 >198107091314360 198107091315420 >198107091326240 198107091330180 >198107091345000 198107091511300 >198107091525000 198107091537240 >198107091547300 198107091547300 >198107091600000 198107091600000 >198107091616180 198107091616180 >198107091630240 198107091709060 >198107091723060 198107091745240 >198107091756300 198107091814300 >198107091830000 198107091830000 >198107091845120 198107091929480 >198107091944420 198107092130000 >198107092144540 198107092144540 >198107092158060 198107092216300 >198107092230120 198107092230120 >198107092240360 198107092245000 >198107092300000 198107092300000 >198107092311420 198107092333060 >198107092359180 198107092359180 >198107100014000 198107100030540 >198107100046120 198107100100000 >198107100115540 198107100115540 >198107100137060 198107100152060 >198107100203060 198107100203060 >198107100215000 198107100215000 >198107100225300 198107100231060 >198107100252060 198107100300000 >198107100314120 198107100314120 >198107100328060 198107100346540 >198107100400000 198107100400000 >198107100411000 198107101159060 >198107101210420 198107101248360 >198107101301360 198107101416300 >198107101500180 198107102202060 >198107102212300 198107110134240 >198107110208540 198107110233240 >198107110244120 198107110345120 >198107110355360 198107110615240 >198107110636240 198107110639480 >198107110652180 198107111026060 >198107111039360 198107111229480 >198107111300180 198107111313120 >198107111337060 198107111449420 >198107111506360 198107111531000 >198107111600000 198107111600000 >198107111615000 198107111615000 >198107111630120 198107111646300 >198107111700000 198107111700000 >198107111716360 198107111716360 >198107111738060 198107111738060 >198107111750180 198107111816360 >198107111830060 198107111830060 >198107111845000 198107111845000 >198107111900180 198107111915000 >198107111930360 198107111930360 >198107111945060 198107112000000 >198107112015060 198107112100120 >198107112111420 198107112130420 >198107112145180 198107112301000 >198107112314480 198107120030120 >198107120045180 198107120200000 >198107120211000 198107120211000 >198107120309240 198107120315000 >198107120330000 198107120330000 >198107120346480 198107120346480 >198107120406000 198107120406000 >198107120417540 198107120417540 >198107120428000 198107120449240 >198107120500000 198107120519480 >198107120530240 198107120545240 >198107120558480 198107120600000 >198107120610240 198107120610240 >198107120624540 198107120624540 >198107120645000 198107120815420 >198107120830000 198107120830000 >198107120842180 198107120929480 >198107120943420 198107120943420 >198107120954000 198107121117000 >198107121129540 198107121316000 >198107121327480 198107121335540 >198107121404360 198107121739540 >198107121752540 198107121830540 >198107121845240 198107121845240 >198107121857180 198107121920360 >198107121930480 198107122030000 >198107122056180 198107122115300 >198107122128360 198107130110300 >198107130124480 198107130234000 >198107130245060 198107130331000 >198107130342000 198107130346120 >198107130357240 198107130500000 >198107130510420 198107130517060 >198107130527360 198107130544540 >198107130600000 198107130600000 >198107130617180 198107130638240 >198107130655180 198107130700000 >198107130720420 198107130720420 >198107130745000 198107130754180 >198107130805420 198107130814540 >198107130830000 198107130830000 >198107130850360 198107130901420 >198107130913240 198107130929540 >198107130957060 198107130957060 >198107131019420 198107131019420 >198107131034060 198107131044540 >198107131115000 198107131219240 >198107131230000 198107131245060 >198107131255300 198107131413120 >198107131546540 198107132145060 >198107132211060 198107140110180 >198107140121420 198107140404360 >198107140415060 198107140800000 >198107140817180 198107140844480 >198107140900000 198107141050300 >198107141104240 198107141717180 >198107141730480 198107141730480 >198107141755240 198107142100540 >198107142118060 198107142130000 >198107142140060 198107142214420 >198107142230360 198107142230360 >198107142241540 198107142300480 >198107142316120 198107142316120 >198107142337120 198107142337120 >198107142347540 198107150000000 >198107150014540 198107150023480 >198107150039300 198107150046420 >198107150100120 198107150248360 >198107150300000 198107150403360 >198107150414540 198107150821300 >198107150858000 198107151624540 >198107151637000 198107151700120 >198107151716180 198107151716180 >198107151728420 198107151745120 >198107151756300 198107160144540 >198107160200180 198107160446420 >198107160530120 198107160918000 >198107160930360 198107160948000 >198107161002060 198107161002060 >198107161020120 198107161037120 >198107161051000 198107161100540 >198107161114060 198107161118180 >198107161145240 198107161145240 >198107161203180 198107161203180 >198107161214540 198107161245060 >198107161315540 198107161332540 >198107161358180 198107161358180 >198107161414300 198107161501300 >198107161513120 198107161513120 >198107161538000 198107161538000 >198107161552300 198107161552300 >198107161604360 198107161814300 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Seismic Shots Data (l-8-81-wg.420_053) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198107090820510 198107090820510 >198107090826310 198107092013010 >198107092104020 198107092219580 >198107092225120 198107100013140 >198107100107000 198107100534470 >198107100540160 198107101732530 >198107101814230 198107102147040 >198107102244290 198107112041030 >198107112046130 198107112050190 >198107112137100 198107112358440 >198107120035370 198107121236440 >198107121357170 198107121624300 >198107121714460 198107121741270 >198107121748020 198107122050560 >198107122057240 198107122112470 >198107122118360 198107122127160 >198107122133410 198107130011460 >198107130050020 198107131053550 >198107131157100 198107131314480 >198107131358410 198107131510020 >198107131517100 198107140308400 >198107140409370 198107140629460 >198107140702380 198107141543270 >198107141618470 198107142005160 >198107142045520 198107142218210 >198107142304240 198107150525310 >198107150545290 198107150904210 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST Unspecified Unspecified Navigation Data >Converted to time format with year at start. > >10/10/85 KAYE DUA0:[DATA.L881WG.N]L881WG.053; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > 19960122 U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG) Clint Steele InfoBank Group Leader mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5055 (650) 329-5190 infobank@octopus.wr.usgs.gov Gravity Data >10/31/1998 /tiger/l/l881wg/grav/l-8-81-wg.151_053 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >10/15/85 BARB DRS$DATA:[L881WG.G]L881WG.151; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > >Input was... >Converted to time format with year at start. > >10/10/85 KAYE DUA0:[DATA.L881WG.N]L881WG.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) Clint Steele InfoBank Group Leader mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5055 (650) 329-5190 infobank@octopus.wr.usgs.gov Magnetics Data >06/20/2012 carolyn l-8-81-wg.220_053 > >Reprocessed using subroutines from Susan Macmillan's >IGRF SYNTHESIS PROGRAM >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/l881wg/mag/l-8-81-wg.200_053 >/bear/programs/edit/automerge/automerge > >Converted to time format with year at start. > >11/20/85 CAROLYN DRS$DATA:[L881WG.M]L881WG.200; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >was L881WG._.MAGSB1 on TAM183 >was L881WG220.DAT on VAM183 > >Converted to time format with year at start. > >10/10/85 KAYE DUA0:[DATA.L881WG.N]L881WG.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) Clint Steele InfoBank Group Leader mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5055 (650) 329-5190 infobank@octopus.wr.usgs.gov Bathymetry Data >10/31/1998 /tiger/l/l881wg/bath/l-8-81-wg.335_053 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >09/04/85 BECKIE DUA0:[DATA.L881WG.B]L881WG.335; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >This file was hand-digetized in 2-way traveltime(secs). > >Input was... >Converted to time format with year at start. > >10/10/85 KAYE DUA0:[DATA.L881WG.N]L881WG.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) Clint Steele InfoBank Group Leader mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5055 (650) 329-5190 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 Bering Sea, Alaska Point Point 0.000001 0.000001 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.25722210100002 l881wg.m77t MGD77T single-beam bathymetry, gravity, and magnetics data file for l881wg 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 19810704 19810716 Year, month, day TIME Time NGDC 0 2359.483 hours and decimal minutes LAT Latitude World Geodetic System 1984 Geographic Coordinate System 53.38091 57.79134 decimal degrees LON Longitude World Geodetic System 1984 Geographic Coordinate System -166.53174 -152.04261 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 0.057 8.955 seconds CORR_DEPTH Bathymetry, corrected depth U.S. Geological Survey 42.8 6781.2 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 50344 54017 gammas MAG_RES Magnetics residual field field NGDC -430.1 540 gammas GRA_OBS Observed gravity NGDC 980836.2 981772.3 milligals EOTVOS EOTVOS correction - E = 7.5 V cos(phi) * sin(alpha) + 0.0042 V*V NGDC -49.6 39.5 milligals FREEAIR Free-air Anomaly = G(observed) minus G(theoretical) NGDC -651.3 177.7 milligals LINEID LINE/TRACK/SEGMENT ID NGDC 100 117 Used, for example, to cross reference with seismic data. POINTID SEISMIC SHOT-POINT NUMBER/POINT ID NGDC 50 4230 Used, for example, to cross reference with seismic data. Bathymetry, magnetic, gravity, and navigation data for U.S. Geological Survey survey l881wg in MGD77T format. Attributes are obtained from MGD77T data files created from the navigation, gravity, magnetics 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. 1.3 http://www.ngdc.noaa.gov/mgg/trk/trackline/samuel_p._lee/l881wg/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