Survey Identifier: HM7002
Format Acronym: MGD77
Data Center File Number: J1030003
Parameters Surveyed Code: 55513
File Creation Date (yyyymmdd): 19801222
Source Institution: HYDROGRAPHIC DEPT.
Country: JAPAN
Platform Name: MEIYO
Platform Type Code: 1
Platform Type: SHIP
Chief Scientist(s): TAKAHIRO SATO
Project: THE BASIC MAP OF SEA OF CONTINENTAL SHELVES
Survey Departure Date (yyyymmdd): 19700604
Port of Departure: TOKYO
Survey Arrival Date (yyyymmdd): 19700723
Port of Arrival: OTARU
Navigation Instrumentation: HOKKAIDO DECCA CHAIN (9CM/MP)
Geodetic Datum/Position: HOKKAIDO DECCA CHAIN (9CM/MP)
Bathymetry Instrumentation: 50KHZ,BEAM-WIDTH 15-DEGREE*2
Additional Forms of Bathymetric Data: ANALOG RECORD
Magnetics Instrumentation: PROTON MAG
Additional Forms of Magnetics Data: CHART 6321M,6322M,6323M
Gravity Instrumentation: TSSG-H1,SENSOR:P1
Additional Forms of Gravity Data: CHART 6321G,6322G,6323G
Seismic Instrumentation: AIR GUN
Formats of Seismic Data: ANALOG RECORD
Topmost Latitude of Survey: +46
Bottommost Latitude: +43
Leftmost Longitude: +139
Rightmost Longitude: +142
General Digitizing Rate of Bathymetry: 100
General Sampling Rate of Bathymetry: 1/SECOND
Assumed Sound Velocity: 15000
Bathymetric Datum Code: 07
General Digitizing Rate of Magnetics: 050
General Sampling Rate of Magnetics: 06
Magnetic Sensor Tow Distance: 250
Reference Field Code: 03
Reference Field: IGRF-65
Method of Applying Residual Field: DIURNAL CORRECTIONS USING DATA OF OBSERVATORY
General Digitizing Rate of Gravity: 100
General Sampling Rate of Gravity: 00
Theoretical Gravity Formula Code: 3
Theoretical Gravity Formula: IAG SYSTEM(1967)
Reference System: SYSTEM JGSN75
Corrections Applied: DRIFT,ETOVOS
Departure Base Station Gravity: 9803910
Departure Base Station Description: HAKODATE 41-46.3N,140-42.9E
Arrival Base Station Gravity: 9805160
Arrival Base Station Description: OTARU 43-12.2N,141-00.3E
Additional Documentation: CRUISE NAME:ISHIKARI RUMOI OKI, OBSERVERS:H.NISHIMURA,Y.TOMIOKA, RUMOI - 43-56.6N,141-38.5E 980579 MGAL, REDUCTION AND COMPILATION OF GRAVITY DATA WERE MADE BY T.TAKEMURA,T.YANAGI AND, Y.TOMOOKA OF THE ASTRONOMICAL DIV. CONVERSION OF POTSDAM INTO IGSN 75 HAS BEEN CARRIED OUT BY Y.GANEKO. magnetics records follow bathy and grav. no times for mag OLD NGDC:56070003
Number of Data Records: 7209
Min/Max Data Record:
Date: 1970 06 15
Latitude: +43.20074
Longitude: +139.04120
Bathymetry, Corrected Depth: 20.0
Magnetics Total Field, 1st Sensor: 496800
Magnetics Residual Field: -04702
Observed Gravity: 9804712
Free-Air Anomaly: -0713
Min/Max Data Record:
Date: 1970 07 24
Latitude: +45.29214
Longitude: +141.71977
Bathymetry, Corrected Depth: 3472.0
Magnetics Total Field, 1st Sensor: 513000
Magnetics Residual Field: +07847
Observed Gravity: 9807082
Free-Air Anomaly: +1350