RRS Discovery D110A

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD110A
Cruise period1980-04-22 — 1980-05-20
Port of departureBalboa, Panama
Port of returnCallao, Peru
Objectives1. To study the tectonics of a fast-spreading mid-ocean ridge (the East Pacific Rise), primarily using Gloria and the 36 kHz sonar. This was to include detailed studies of the spreading axis and at least one transform fault.
2. To make a similar study of a medium-spreading ridge. This was to include a study of the 'propagating rift' at 95W, where an offset in the spreading centre is apparently propagating along the ridge axis.
3. To make a detailed study of the tectonics of the Galapagos Triple Junction using primarily the side-scan sonars.
4. To determine the precise location of the Pacific-Nazca plate boundary between the Quebrada and Gofar fracture zones on the East Pacific Rise.
5. To deploy five ocean bottom seismographs (OBS) in one of the East Pacific Rise fracture zones.
6. To undertake a Gloria survey of the Peru Trench.
7. To investigate the morphology and tectonics of the southern Panama continental margin.
8. To conduct Gloria surveys of IPOD sites 501/504 and 505 in the Coasta Rica Rift.
9. To sample oxyhydroxide-rich sediment in the Bauer Deep.
10. To compare mineralogy, sedimentary history and pore-water profiles between the Bauer Deep and East Pacific Rise flank and crest.
11. To study the variations in mineralogy and pore-water composition between stations above and below the carbonate compensation depth, and if possible across a buried redox horizon.
12. To obtain information on the biogeochemistry of the Peru shelf and slope sediments by coring and sediment trap deployment.
13. To core metal-rich sediments in Hess Deep for analysis by D. Cronan, Imperial College.
Chief scientistRoger C Searle (Institute of Oceanographic Sciences Wormley Laboratory)
Cruise reportRRS Discovery D110A cruise report d110.pdf (1.75 MB) 
Ocean/sea areas 
GeneralNorth East Pacific Ocean (limit 180W)
South East Pacific Ocean (limit 140W)
SpecificE. Pacific Rise/ Galapagos Rift
Track chartsRRS Discovery D110A cruise track — trk2758.html
Physical oceanography 
Other physical oceanographic measurementsQuantity: number of profiles = 2
Description: sound velocity stations
Chemical oceanography 
Other chemical oceanographic measurementsQuantity: number of samples = 1
Description: surface water sample for chemical work
Biology and fisheries 
Sediment trapsQuantity: number of deployments = 1
Description: for chemical work
Other biological/fisheries measurementQuantity: number of deployments = 4
Description: near surface nets for chemical work
Routine standard measurements
Geology and geophysics 
Core - soft bottomQuantity: number of cores = 19
Description: gravity, box & kasten for chemical work (over 2 legs)
Single-beam echosoundingQuantity: track kilometres = 15186.4
Description: over 2 legs
Long/short range side scan sonarQuantity: track kilometres = 15093.8
Description: 1550nm 2kHz & 6600nm 36kHz (over 2 legs)
Long/short range side scan sonarQuantity: track kilometres = 10371.2
Description: GLORIA (over 2 legs)
Single channel seismic reflectionQuantity: track kilometres = 8334
Description: over 2 legs
Gravity measurementsQuantity: track kilometres = 15186.4
Description: over 2 legs
Magnetic measurementsQuantity: track kilometres = 11667.6
Description: over 2 legs
Other geological/geophysical measurementsQuantity: number of deployments = 3
Description: porewater sampler for chemical work