RRS Discovery D111A

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD111A
Cruise period1980-06-21 — 1980-07-03
Port of departureBalboa, Panama
Port of returnHalifax, Canada
ObjectivesThe first leg of Discovery Cruise 111 was to have been primarily a transit leg from Balboa Panama to Halifax, Nova Scotia with little time allowed for underway geophysical profiling. However, the previous December the charter ship RV Starella, on passage from Jacksonville, Florida to San Juan, Puerto Rico had obtained a GLORIA survey track over the Bahama Outer Ridge. The large scale sedimentary bedforms observed on the resulting sonographs were impressive. Thus a second passage track with GLORIA and 2 kHz high resolution seismic profiling was planned for this Cruise 111 transit leg. Allowance was made for Discovery to arrive in Halifax one day later than originally planned and it was hoped that an early transit of the Panama Canal and fair weather on transit would provide time for a deviation to the Blake-Bahama Outer Ridge area.
On the survey area the objectives mainly involved mapping of sea bed morphology using GLORIA and interpretation of large scale sedimentary features through 2 kHz high-resolution and precision echosounder profiling, and later linking these to 3.5 kHz profiles of Lamont-Doherty Geological Observatory. The resulting zonation of bottom morphology would then be related to current flow in the Western Boundary Undercurrent which is believed to have constructed the Outer Ridge themselves.
Chief scientistRobert B Kidd (Institute of Oceanographic Sciences Wormley Laboratory)
Cruise reportRRS Discovery D111A cruise report d111a.pdf (0.34 MB) 
Ocean/sea areas 
GeneralNorth West Atlantic Ocean (limit 40W)
Caribbean Sea
SpecificN.W. Atlantic
Track chartsRRS Discovery D111A cruise track — trk2445.html RRS Discovery D111A cruise track — trk2445b.html
Routine standard measurementsQuantity: track kilometres = 5622
Geology and geophysics 
Multi-beam echosoundingQuantity: track kilometres = 2667
Long/short range side scan sonarQuantity: track kilometres = 1333
Gravity measurementsQuantity: track kilometres = 5622
Magnetic measurementsQuantity: track kilometres = 2667
Other geological/geophysical measurementsQuantity: track kilometres = 1333
Description: Gloria
Other geological/geophysical measurementsQuantity: track kilometres = 2000
Description: 2 kHz profiler