Cruise inventory

RRS Discovery D205

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD205
Cruise period1993-11-10 — 1993-12-07
StatusCompleted
Port of departureLas Palmas, Spain
Port of returnCadiz, Spain
PurposeResearch
ObjectivesTOBI surveys and coring of debris flows west of the Canaries

1) To collect TOBI sidescan sonar and profiler data and sediment cores from the distal part of the Saharan Sediment Slide and the proximal area (slide scar) of the Canary Slide.

Collecting TOBI and core data from the Saharan Slide
a.To investgate in more detail the spectacular flow fabric imagined during a previous reconnaissance survey of a small part of the Saharan Slide, with the objective of understanding the mechanisms of its formation
b.To investigate how the flow fabric might change downslope, and to examine what this might tell about the mechanisms
c.To compare the fabrics of the Saharan and Canary slides, and to investigate what this might tell about the flow characteristics of 2 slides

Collecting TOBI data from the slide scar area of the Canary Slide
a.To investigate possible failure mechanisms, such as rotational block faulting, slip on slope-parallel bedding planes or detachment of the whole sediment cover from the underlying bedrock
b.To see whether blocks gradually disintegrate as they move downslope or whether the whole slide mass fluidises in place and then flows downslope
c.To look for clues as the triggering mechanisms, such as fluid escape structures or evidence for submarine volcanic eruptions, and to investigate whether the slide is related to the collapse of the part of the island of Hierro

2) Instrumented trials to test the new scatterometer instrument on TOBI
3) Completion of a coring transect along the axis of the Agadir basin south east of Madeira
Chief scientistDouglas G Masson (Institute of Oceanographic Sciences Deacon Laboratory)
Cruise reportRRS Discovery D205 cruise report d205.pdf — access key 'C' (7.86 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
SpecificEastern Atlantic
Track chartsRRS Discovery D205 cruise track — d205track1.pdf (0.20 MB)  RRS Discovery D205 cruise track — d205track2.pdf (0.25 MB)  RRS Discovery D205 cruise track — d205track3.pdf (0.22 MB) 
Measurements 
Meteorology 
Other meteorological measurementsQuantity: number of deployments = 8
Description: 9.5 days allocated to TOBI operations, 5.25 days to coring, 3.25 days to scatterometer trials. For all but the first (lasting 3 days) the vehicle was fitted with the scatterometer hardware and for runs 2, 6, 7, and 8 the scatterometer electronics were included. 800 track km of TOBI data
Geology and geophysics 
Core - soft bottomQuantity: number of cores = 12
Description: Piston sediment cores taken, restricted to a minimum of 3 barrels (2 at 7.5m and 3 at 10.5 m). 69.9 m of core from 7 straight cores was recovered from a maximum to 75 m. On recovery, all of the cores were logged using the IOSDL P-Wave logger and stored in the ship's sample cold store at 4 degrees centigrade
Long/short range side scan sonarQuantity: number of deployments = 8
Description: 9.5 days allocated to TOBI operations, 5.25 days to coring, 3.25 days to scatterometer trials. For all but the first (lasting 3 days) the vehicle was fitted with the scatterometer hardware and for runs 2, 6, 7, and 8 the scatterometer electronics were included. 800 track km of TOBI data