Survey Identifier: EW9011
Format Acronym: MGD77
Data Center File Number: 01210035
Parameters Surveyed Code: 55531
File Creation Date (yyyymmdd): 19951118
Source Institution: LAMONT-DOHERTY EARTH OBSERVATORY (LDEO)
Country: USA
Platform Name: R/V MAURICE EWING
Platform Type Code: 1
Platform Type: SHIP
Chief Scientist(s): J.FOX, N.GRINDLAY
Project: MID-ATLANTIC RIDGE
Funding: NSF OCE89-17762
Survey Departure Date (yyyymmdd): 19901216
Port of Departure: RECIFE, BRAZIL
Survey Arrival Date (yyyymmdd): 19910125
Port of Arrival: PUNTA ARENAS, CHILE
Navigation Instrumentation: MAGNAVOX MX-1107RS TRANSIT, T-SET GPS
Geodetic Datum/Position: GPS/SATELLITE/LORAN + SPEED/HEADING
Bathymetry Instrumentation: ATLAS HYDROSWEEP-DS MULTIBEAM SONAR
Additional Forms of Bathymetric Data: RAYTHEON 3.5KHZ, 12KHZ PDR
Magnetics Instrumentation: VARIAN V-75 MAGNETOMETER
Gravity Instrumentation: BODENSEEWERKE KSS-30 GRAVIMETER
Additional Forms of Gravity Data: BELL BGM-3 GRAVIMETER
Seismic Instrumentation: NO SEISMIC DATA COLLECTED
Topmost Latitude of Survey: -08
Bottommost Latitude: -53
Leftmost Longitude: -071
Rightmost Longitude: -011
General Digitizing Rate of Bathymetry: 010
Assumed Sound Velocity: 15000
Bathymetric Datum Code: 00
Interpolation Scheme: 1-MINUTE INTERVALS
General Digitizing Rate of Magnetics: 010
Reference Field Code: 12
Reference Field: IGRF-85
Method of Applying Residual Field: BILINEAR INTERPOLATION IN 1-DEGREE SQUARE
General Digitizing Rate of Gravity: 010
Theoretical Gravity Formula Code: 2
Theoretical Gravity Formula: INTERNATIONAL 30
Reference System Code: 2
Reference System: POTSDAM SYSTEM
Corrections Applied: DRIFT .0779 MGAL/DAY, DC 5.81
Departure Base Station Gravity: 9781625
Departure Base Station Description: DOD02242-3
Arrival Base Station Gravity: 9813159
Arrival Base Station Description: GW-97
Additional Documentation: TIME: KINEMETRICS 468-DC, SPEED: FURUNO CI-30, HEADING: SPERRY MK-27, LORAN: INTERNAV LC-408, DMEC NORTHSTAR-6000, Sound Velocity was corrected with XBT's and NODC historic data. The automatic, correction feature was found to be as much as 20 m/sec in error. SCIENCE OFFICER: J.GREER; COMPUTER SYSTEMS: W.ROBINSON; DATA REDUCED BY LDEO, MARINE OFFICE DATA REDUCTION GROUP; ORIGINAL RECORDS ARCHIVED AT LDEO; NO MULTIBEAM DATA AVAILABLE AT NGDC NORTH OF 10 S. OR WEST OF 56 W.
Number of Data Records: 56136
Min/Max Data Record:
Date: 1990 12 17
Latitude: -52.97333
Longitude: -70.52800
Bathymetry, 2- Way Traveltime: 022670
Bathymetry, Corrected Depth: 1689.0
Magnetics Total Field, 1st Sensor: 247740
Magnetics Residual Field: -08470
Free-Air Anomaly: -0530
Min/Max Data Record:
Date: 1991 01 25
Latitude: -8.04645
Longitude: -11.35246
Bathymetry, 2- Way Traveltime: 081860
Bathymetry, Corrected Depth: 6177.0
Magnetics Total Field, 1st Sensor: 279900
Magnetics Residual Field: +06770
Free-Air Anomaly: +0841