RRS Discovery D110A
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Discovery (74E3) |
| Cruise identifier | D110A |
| Cruise period | 1980-04-22 — 1980-05-20 |
| Status | Completed |
| Port of departure | Balboa, Panama |
| Port of return | Callao, Peru |
| Purpose | Research |
| Objectives | 1. 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 scientist | Roger C Searle (Institute of Oceanographic Sciences Wormley Laboratory) |
| Cruise report |  (1.75 MB) |
| Ocean/sea areas | |
| General | North East Pacific Ocean (limit 180W) South East Pacific Ocean (limit 140W) |
| Specific | E. Pacific Rise/ Galapagos Rift |
| Track charts |  |
| Measurements | |
| Physical oceanography | |
| Other physical oceanographic measurements | Quantity: number of profiles = 2 Description: sound velocity stations |
| Chemical oceanography | |
| Other chemical oceanographic measurements | Quantity: number of samples = 1 Description: surface water sample for chemical work |
| Biology and fisheries | |
| Sediment traps | Quantity: number of deployments = 1 Description: for chemical work |
| Other biological/fisheries measurement | Quantity: number of deployments = 4 Description: near surface nets for chemical work |
| Meteorology | |
| Routine standard measurements | |
| Geology and geophysics | |
| Core - soft bottom | Quantity: number of cores = 19 Description: gravity, box & kasten for chemical work (over 2 legs) |
| Single-beam echosounding | Quantity: track kilometres = 15186.4 Description: over 2 legs |
| Long/short range side scan sonar | Quantity: track kilometres = 10371.2 Description: GLORIA (over 2 legs) |
| Long/short range side scan sonar | Quantity: track kilometres = 15093.8 Description: 1550nm 2kHz & 6600nm 36kHz (over 2 legs) |
| Single channel seismic reflection | Quantity: track kilometres = 8334 Description: over 2 legs |
| Gravity measurements | Quantity: track kilometres = 15186.4 Description: over 2 legs |
| Magnetic measurements | Quantity: track kilometres = 11667.6 Description: over 2 legs |
| Other geological/geophysical measurements | Quantity: number of deployments = 3 Description: porewater sampler for chemical work |
