Field Activity 1987-001-FA

Identifier 1987-001-FA
Alternate names STRL 87-1
Purpose To provide further geophysical data to aid the interpretation of a GLORIA survey conducted in the area in October 1985, and to obtain knowledge pertinent to the general structural analysis of the northern boundary of the Caribbean Plate. The GLORIA survey consisted of a grid in the central Cayman Trough and a single swath eastward through the Trough to the Windward Passage.
Location Cayman Trough, Jamaica, Cayman Islands, Caribbean Sea, North America, North Atlantic;
Summary The cruise operated in the eastern Cayman Trough, northeast and north of Jamaica, and in the central Cayman Trough, south of the Cayman Islands. The seismic system operated well throughout the cruise, once initial streamer problems were worked out. End points of seismic profiles are indicated in the appendix. A total of 1270 nautical miles (2352 km) of seismic data were collected. The Starfix navigation system worked perfectly throughout the cruise giving excellent results. The gravity system also worked well. Unfortunately, both the magnetometer and seismic tape recorder failed early in the cruise, and, after considerable effort, were found to be unrepairable. The tape recorder had mechanical problems in the tape takeup system. The magnetometer first developed noise due to inadequate fluid in the bottle resulting from a broken pressure-compensating diaphragm. An emergency repair was made by D. Nichols, consisting of removing the diaphragm, sealing the pressure compensation holes in the bottle, and filling it with clean diesel fuel. This worked well and provided excellent, quiet data for about a day. However, further problems developed due to short circuits in the tow cable which were unrepairable. Eastern Cayman Trough Survey: 9 survey lines; Central Cayman Trough Survey: 22 survey lines.
Comments Original Center People field contained: William Dillon, co-Ch. Sci.; Terence Edgar, co-Ch. Sci.; Dave Nichols, Electronics Technician; David Mason, Seismic Technician; C. Delorey, Watch Stander, Cruise Data Curator; R. Diaz, Watch Stander.
Platform
Starella
Length: 73 meters; Beam: 11 meters.
Itinerary
Start Kingston, Jamaica 1987-01-07
End Kingston, Jamaica 1987-01-19
Days in the field 12
Bounds
West -82.3
East -75
North 19.2
South 17.4

Personnel

Organization
384 Woods Hole Road
Quissett Campus
Woods Hole, MA02543-1598
(508) 548-8700
Principal investigators William P DillonTerry Edgar
Crew members
David H Mason
Scientist, Staff
William P Dillon
Scientist, Staff
David R Nichols
Scientist, Staff
Catherine Delorey
Scientist, Staff
Terry Edgar
Scientist, Staff
Information specialist(s)
Catherine Delorey
Specialist, Information
Affiliate staff R. Diaz, Watch Stander; C. Heywood, Nav.-Grav. Technician (Branch of Pacific Marine Geology); H. Carvajal, Watch Stander and Observer (INGEOMINAS, Colombia); J. Banhan, Watch Stander and Observer (Geological Survey of Jamaica)

Data types and categories

Data category: Electro-Magnetic, Location-Elevation, Seismics, Sonar
Data type: Gravity, Magnetics, Navigation, Air Gun / Water Gun, Single Beam

Documents: Notes and log books

Name Survey Equipment Description
Cruise report (document not focused on specific equipment) Chief Scientist's report including personnel, equipment, narrative, and navigation waypoints.
Navigation log Starfix navigation system Handwritten navigation log including navigation fixes, start and end of lines and tapes.
Geophysics log Air gun Air gun log containing start and end of lines and tapes, equipment configuration, data acquisition notes.

Equipment used

Equipment Usage description Data types Datasets
Air gun Air Gun / Water Gun (no data reported)
Marine magnetometer Magnetics (no data reported)
Echosounder Single Beam (no data reported)
Gravity meter (wh) Gravity 1
Starfix navigation system Navigation 2
Single channel hydrophone Air Gun / Water Gun, Boomer, Bubble Gun, Sparker, Sub Bottom Profiler 3

Datasets

Datasets produced in this activity

Dataset name Equipment Description Dataset contact
1987-001-FA-GP-001 Gravity meter (wh) Digital tape(s) of GRAV, Nancy K. Soderberg
1987-001-FA-LN-001 Starfix navigation system Navigation trackline plot for field activity 87001 Nancy K. Soderberg
1987-001-FA-LN-002 Starfix navigation system Digital tape(s) of NV, Nancy K. Soderberg
1987-001-FA-SE-001 Single channel hydrophone Collection of paper record displays of seismic data( 12K) for lines Nancy K. Soderberg
1987-001-FA-SE-002 Single channel hydrophone microfilm of Nancy K. Soderberg
1987-001-FA-SE-003 Single channel hydrophone analog tape of seismic data Nancy K. Soderberg

Publications

Samples collected during this field activity