Resources

RRS James Cook JC187

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Cook (740H)
Cruise identifierJC187
Cruise period2019-08-31 — 2019-10-07
StatusCompleted
Port of departureMindelo, Cape Verde
Port of returnWalvis Bay, Namibia
PurposeResearch
ObjectivesOverall Aims
The first overall aim of the project is to understand the speed, frequency, runout distance, and character of turbidity currents within the Congo Canyon. We also seek to understand how turbidity currents form seafloor deposits, and sculpt seabed morphology. This information will help with geohazard assessment and planning of future submarine cable routes across the Congo Canyon. The second overall aim is to determine whether hydrophones or geophones can record turbidity currents, and thus provide information on their frequency, duration or character. A series of subsidiary aims include the following. The third aim is to understand how organic carbon is transferred, fractionated and buried by turbidity currents. The fourth aim is to test whether turbidity currents transport microplastic particles to the deep sea. A final aim is to understand the distribution and abundance of EPS (Extracellular Polymetric Substances) on the canyon floor, which is a sticky substance secreted by organisms that may affect the cohesive properties of the seabed.

Brief Narrative
Research cruise JC187 was very successful. It deployed 11 acoustic Doppler current profiler (ADCP) moorings, 12 Ocean Bottom Seismometers and a hydrophone array along the Congo Canyon. This comprises 7 ADCP-moorings at 5 sites in the upper canyon, within Angolan waters. A further 4 ADCP-moorings were then deployed at 4 sites within deeper International Waters. A total of 25 mega-cores (~50 cm long that capture the sediment-water interface) and 20 much longer (up to 15 m) piston cores were collected. To help locate moorings, detailed (5-15 m horizontal resolution) bathymetric surveys were completed between all 5 mooring sites in Angolan waters, along a ~70 km length of the canyon. Detailed bathymetry was also collected along the entire canyon length within International Waters. The moorings will now be recovered by a second NERC-funded cruise in Oct-Dec 2020, and we will see whether the ADCPs and other sensors have recorded the frequency, runout and nature of turbidity currents moving down the canyon.
Chief scientistPeter J Talling (University of Durham Department of Geography)
Cruise reportRRS James Cook JC187 cruise report jc187.pdf (27.41 MB) 
Ocean/sea areas 
GeneralSouth East Atlantic Ocean (limit 20W)
SpecificCongo Canyon and channel system
Measurements 
Physical oceanography 
CTD stationsQuantity: number of profiles = 11
Description: CTD cast and SVP
Geology and geophysics 
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 19
Core - soft bottomQuantity: number of cores = 4
Description: Multicore 03
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 08
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 17
Core - soft bottomQuantity: number of cores = 4
Description: Multicore (MC) – 02
Core - soft bottomQuantity: number of cores = 4
Description: Multicore 04
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 05
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 06
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 07
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 10
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 11
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 12
Core - soft bottomQuantity: number of samples = 5
Description: Multicore 14 Sediment Bags
Core - soft bottomQuantity: number of cores = 2
Description: Multicore 15
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 18
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 20
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 22
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 24
Core - soft bottomQuantity: number of cores = 20
Description: Piston core
Core - soft bottomQuantity: number of cores = 1
Description: Multicore 13
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 16
Core - soft bottomQuantity: number of cores = 3
Description: Multicore 21
Core - soft bottomQuantity: number of cores = 1
Description: Multicore 23
Core - soft bottomQuantity: number of cores = 4
Description: Multicore 25
Multi-beam echosoundingQuantity: track kilometres = 415
Description: Multibeam survey of channel in international waters
Multi-beam echosoundingQuantity: track kilometres = 75
Description: Multibeam survey of upper canyon
Moorings, landers, buoys 
Physical oceanography 
CTD stations5° 52' 8" S  6° 55' 31" E — Mooring 6: CTD and 300 kHz ADCP 79 m ASB deployed 29/09/19
CTD stations5° 50' 12" S  11° 2' 9" E — Mooring 9: CTD 44 m ASB, 600 kHz ADCP 44 m ASB, CTD 34 m ASB, sediment trap 32 m ASB deployed 21/09/19
CTD stations5° 57' 12" S  11° 33' 12" E — Mooring 3: CTD and 300 kHz ADCP 65 m ASB deployed 20/09/19
CTD stations5° 52' 44" S  11° 10' 29" E — IFREMER Aniitra-3 mooring, 75 kHz ADCP 250 m ASB and sediment traop 40 m ASB, deployed 21/09/19
CTD stations5° 54' 0" S  11° 19' 45" E — IFREMER Aniitra-2 mooring, 75 kHz ADCP 250 m ASB and sediment traop 40 m ASB, deployed 19/09/19
CTD stations5° 55' 27" S  11° 28' 24" E — Mooring 4: CTD and 300 kHz ADCP 65 m ASB deployed 20/09/19
CTD stations6° 41' 45" S  5° 28' 57" E — Mooring 8: CTD and 300 kHz ADCP 79 m ASB deployed 10/09/19 recovered 01/10/2019.
CTD stations5° 43' 53" S  8° 7' 18" E — Mooring 5: CTD and 300 kHz ADCP 79 m ASB deployed 28/09/19
CTD stations5° 45' 24" S  7° 40' 28" E — Mooring 8-R: CTD and 300 kHz ADCP 79 m ASB deployed 02/10/19
CTD stations5° 54' 1" S  11° 19' 54" E — Mooring 1: CTD and 300 kHz ADCP 65 m above the seabed (ASB) deployed 19/09/19
CTD stations6° 27' 51" S  6° 2' 47" E — Mooring 7: CTD 30 m ASB, Sediment trap 23m ASB, CTD and 300 kHz ADCP 79 m ASB deployed 11/09/19
CTD stations5° 50' 13" S  11° 2' 20" E — Mooring 2: CTD 153 m ASB, 75 kHz ADCP 152 m ASB, CTD 65 m ASB, 300 kHz ADCP 65 m, Hydrophone 50 m ASB deployed 25/09/19
Current profiler (eg ADCP)5° 50' 12" S  11° 2' 9" E — Mooring 9: CTD 44 m ASB, 600 kHz ADCP 44 m ASB, CTD 34 m ASB, sediment trap 32 m ASB deployed 21/09/19
Current profiler (eg ADCP)6° 41' 45" S  5° 28' 57" E — Mooring 8: CTD and 300 kHz ADCP 79 m ASB deployed 10/09/19 recovered 01/10/2019.
Current profiler (eg ADCP)6° 27' 51" S  6° 2' 47" E — Mooring 7: CTD 30 m ASB, Sediment trap 23m ASB, CTD and 300 kHz ADCP 79 m ASB deployed 11/09/19
Current profiler (eg ADCP)5° 43' 53" S  8° 7' 18" E — Mooring 5: CTD and 300 kHz ADCP 79 m ASB deployed 28/09/19
Current profiler (eg ADCP)5° 55' 27" S  11° 28' 24" E — Mooring 4: CTD and 300 kHz ADCP 65 m ASB deployed 20/09/19
Current profiler (eg ADCP)5° 57' 12" S  11° 33' 12" E — Mooring 3: CTD and 300 kHz ADCP 65 m ASB deployed 20/09/19
Current profiler (eg ADCP)5° 54' 1" S  11° 19' 54" E — Mooring 1: CTD and 300 kHz ADCP 65 m above the seabed (ASB) deployed 19/09/19
Current profiler (eg ADCP)5° 52' 44" S  11° 10' 29" E — IFREMER Aniitra-3 mooring, 75 kHz ADCP 250 m ASB and sediment traop 40 m ASB, deployed 21/09/19
Current profiler (eg ADCP)5° 52' 8" S  6° 55' 31" E — Mooring 6: CTD and 300 kHz ADCP 79 m ASB deployed 29/09/19
Current profiler (eg ADCP)5° 45' 24" S  7° 40' 28" E — Mooring 8-R: CTD and 300 kHz ADCP 79 m ASB deployed 02/10/19
Current profiler (eg ADCP)5° 50' 13" S  11° 2' 20" E — Mooring 2: CTD 153 m ASB, 75 kHz ADCP 152 m ASB, CTD 65 m ASB, 300 kHz ADCP 65 m, Hydrophone 50 m ASB deployed 25/09/19
Current profiler (eg ADCP)5° 54' 0" S  11° 19' 45" E — IFREMER Aniitra-2 mooring, 75 kHz ADCP 250 m ASB and sediment traop 40 m ASB, deployed 19/09/19
Geology and geophysics 
Geophysical measurements made at depth5° 45' 15" S  8° 7' 37" E — OBS-6 deployed 28/09/2019
Geophysical measurements made at depth6° 14' 21" S  6° 25' 50" E — German OBS-1 deployed 12/09/2019
Geophysical measurements made at depth5° 54' 29" S  11° 27' 23" E — OBS-4 deployed 20/09/2019
Geophysical measurements made at depth5° 57' 48" S  11° 31' 41" E — OBS-2 deployed 20/09/2019
Geophysical measurements made at depth5° 55' 58" S  11° 27' 16" E — OBS-3 deployed 20/09/2019
Geophysical measurements made at depth5° 54' 52" S  6° 53' 25" E — OBS-9 deployed 29/09/2019
Geophysical measurements made at depth6° 28' 34" S  6° 2' 29" E — German OBS-2 deployed 01/10/2019
Geophysical measurements made at depth5° 44' 6" S  7° 37' 58" E — OBS-10 deployed 02/10/2019
Geophysical measurements made at depth5° 45' 52" S  7° 51' 55" E — OBS-7 deployed 28/09/2019
Geophysical measurements made at depth5° 50' 51" S  11° 1' 52" E — OBS-5 deployed 22/09/2019
Geophysical measurements made at depth5° 54' 35" S  11° 19' 54" E — OBS-1 (Ocean Bottom Seiesmometers) deployed 19/09/2019
Geophysical measurements made at depth5° 46' 29" S  7° 16' 8" E — OBS-8 deployed 28/09/2019
Other geological/geophysical measurements5° 50' 45" S  11° 1' 33" E — OBIC hydrophone mooring array, 20 hydrophones in vertical array, deployed 22/09/19
Other geological/geophysical measurements5° 50' 12" S  11° 2' 9" E — Mooring 9: CTD 44 m ASB, 600 kHz ADCP 44 m ASB, CTD 34 m ASB, sediment trap 32 m ASB deployed 21/09/19
Other geological/geophysical measurements5° 54' 0" S  11° 19' 45" E — IFREMER Aniitra-2 mooring, 75 kHz ADCP 250 m ASB and sediment traop 40 m ASB, deployed 19/09/19
Other geological/geophysical measurements6° 27' 51" S  6° 2' 47" E — Mooring 7: CTD 30 m ASB, Sediment trap 23m ASB, CTD and 300 kHz ADCP 79 m ASB deployed 11/09/19
Other geological/geophysical measurements5° 52' 44" S  11° 10' 29" E — IFREMER Aniitra-3 mooring, 75 kHz ADCP 250 m ASB and sediment traop 40 m ASB, deployed 21/09/19
Other geological/geophysical measurements5° 50' 13" S  11° 2' 20" E — Mooring 2: CTD 153 m ASB, 75 kHz ADCP 152 m ASB, CTD 65 m ASB, 300 kHz ADCP 65 m, Hydrophone 50 m ASB deployed 25/09/19