U.S. Geological Survey
Coastal and Marine Geology Program
2013
l1182cs.m77t - MGD77 data file for Geophysical data from field activity L-11-82-CS in Chukchi Sea, Alaska from 08/27/1982 to 09/16/1982
tab-delimited ASCII text files
Menlo Park, CA
U.S. Geological Survey
http://www.ngdc.noaa.gov/mgg/trk/trackline/samuel_p._lee/l1182cs/mgd77/
Wm. Clinton Steele
Carolyn H. Degnan
Gary B. Deeter
Jean A. Riordan
1980
DESCRIPTION OF MARINE GEOPHYSICAL DATA COLLECTED BY THE U.S. GEOLOGICAL SURVEY AND HOW TO OBTAIN IT
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-11-82-CS in Chukchi Sea, Alaska from 08/27/1982 to 09/16/1982, http://walrus.wr.usgs.gov/infobank/l/l1182cs/html/l-11-82-cs.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/l1182cs/html/l-11-82-cs.bath.html, http://walrus.wr.usgs.gov/infobank/l/l1182cs/html/l-11-82-cs.grav.html, and http://walrus.wr.usgs.gov/infobank/l/l1182cs/html/l-11-82-cs.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.
19820827
19820916
ground condition
None planned
-172.04776
-156.79243
72.90967
64.39909
USGS Metadata Identifier
USGS:dae1d42d-602d-49fd-b8a9-7bbde30f9eb3
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)
AK
Alaska
Chukchi Sea
Chukchi 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
Hittelman, Allen M., Groman, Robert C., Haworth, Richard T., Holcombe, Troy L., McHendrie, Graig, Smith, Stuart M., and Metzger, Dan R.
2010
The marine geophysical data exchange format - MGD77 / MGD77T
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-11-82-cs.054 [SINS]) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198208271912470 198208271912470 >198208272014470 198208292339000 >198208292345000 198208300803430 >198208300809430 198208301049430 >198208301103430 198209040240000 >198209060404000 198209091211000 >198209091219000 198209101622210 >198209101630550 198209101917500 >198209101924250 198209161906000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Gravity Data (l-11-82-cs.152_054) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198209060428420 198209060720420 >198209060747420 198209060850420 >198209060908420 198209061211420 >198209061234420 198209070013420 >198209070025420 198209071057420 >198209071122420 198209071439420 >198209071505420 198209071539420 >198209071600000 198209081859180 >198209092000000 198209120210000 >198209120242000 198209120359000 >198209120445000 198209130329000 >198209130342000 198209131457000 >198209131509000 198209131705000 >198209131730000 198209131831000 >198209131858000 198209131917000 >198209131940000 198209140319000 >198209140331000 198209140506000 >198209140519000 198209140629000 >198209141201000 198209142059000 >198209150345420 198209150409420 >198209150510420 198209150639420 >198209150645420 198209150728420 >198209150740420 198209151540420 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Magnetics Data (l-11-82-cs.220_054) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198208302350200 198208311022320 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Bathymetry Data (l-11-82-cs.301_054) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Seismic Shots Data (l-11-82-cs.420_054) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198209071012060 198209080403140 >198209092035370 198209100640080 >198209101057130 198209101221570 >198209101226580 198209101226580 >198209101232010 198209101232010 >198209101237080 198209101237080 >198209101242260 198209101242260 >198209101247380 198209110021230 >198209110708100 198209112008150 >198209112014250 198209120435310 >198209120451010 198209130044020 >198209130050120 198209131155360 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST
Unspecified
Unspecified
Navigation Data >Converted to time format with year at start. > >06/14/85 KAYE USR$DISK:[DRS.DATA.L1182CS.N]LB82CS.054; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1182cs.sinse1._. >
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/l1182cs/grav/l-11-82-cs.152_054 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >Input was... >Converted to time format with year at start. > >06/14/85 KAYE USR$DISK:[DRS.DATA.L1182CS.N]LB82CS.054; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1182cs.sinse1._. > >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-11-82-cs.220_054 > >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/l1182cs/mag/l-11-82-cs.200_054 >/bear/programs/edit/automerge/automerge > >Converted to time format with year at start. > >12/16/85 CAROLYN DRS$DATA:[LB82CS.M]LB82CS.200; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >was L1182CS._.MAGSB1 on TAM414 >was LA82CS220.DAT on VAM414 > >Converted to time format with year at start. > >06/14/85 KAYE USR$DISK:[DRS.DATA.L1182CS.N]LB82CS.054; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1182cs.sinse1._. > >time, lat, long, time(sec) to nearest nav fix, data values
20120620
U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG)
Carolyn H. Degnan
Geophysicist
mailing and physical address
USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
Santa Cruz
CA
95060-5792
USA
(831) 460-7452
(831) 427-4748
infobank@octopus.wr.usgs.gov
Bathymetry Data >10/31/1998 /tiger/l/l1182cs/bath/l-11-82-cs.301_054 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >11/21/85 BECKIE DUA0:[DATA.L1182CS.B]LB82CS.301; >DRB0:[DRS.DSMPL]DESAMTIME.EXE;1 >This file is digitrack bathy desampled to 2 minutes. > > >Input was... >Converted to time format with year at start. > >06/14/85 KAYE USR$DISK:[DRS.DATA.L1182CS.N]LB82CS.054; >USR$DISK:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1182cs.sinse1._. > >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
Chukchi Sea, Alaska
Point
Point
0.000001
0.000001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.25722210100002
l1182cs.m77t
MGD77T single-beam bathymetry, gravity, and magnetics data file for L1182CS
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
19820827
19820916
Year, month, day
TIME
Time
NGDC
0
2359.5
hours and decimal minutes
LAT
Latitude
World Geodetic System 1984 Geographic Coordinate System
64.39909
72.90967
decimal degrees
LON
Longitude
World Geodetic System 1984 Geographic Coordinate System
-172.04776
-156.79243
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
0.007
10.935
seconds
CORR_DEPTH
Bathymetry, corrected depth
U.S. Geological Survey
5.3
8201.3
decimal meters
BAT_CPCO
Bathymetric Correction code - details the procedure used for determining the sound velocity correction to depth
NGDC
63
97
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
5680
57359
gammas
MAG_RES
Magnetics residual field field
NGDC
-95.7
409.1
gammas
GRA_OBS
Observed gravity
NGDC
982500.6
982779.6
milligals
EOTVOS
EOTVOS correction - E = 7.5 V cos(phi) * sin(alpha) + 0.0042 V*V
NGDC
-28.1
31.2
milligals
FREEAIR
Free-air Anomaly = G(observed) minus G(theoretical)
NGDC
-38.5
41.1
milligals
LINEID
LINE/TRACK/SEGMENT ID
NGDC
224
231
Used, for example, to cross
reference with seismic data.
POINTID
SEISMIC SHOT-POINT NUMBER/POINT ID
NGDC
50
6100
Used, for example, to cross
reference with seismic data.
Bathymetry, gravity, magnetic, and navigation data for U.S. Geological Survey bathymetry survey L1182CS 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.
2.0
http://www.ngdc.noaa.gov/mgg/trk/trackline/samuel_p._lee/l1182cs/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