RRS James Clark Ross JR20080823 (JR211)
Cruise summary report
| Cruise Info. | |||||||||
| Ship name (ship code) | RRS James Clark Ross (74JC) | ||||||||
| Cruise identifier | JR20080823 (JR211) | ||||||||
| Cruise period | 2008-08-23 — 2008-09-24 | ||||||||
| Status | Completed | ||||||||
| Port of departure | Longyearbyen, Svalbard and Jan Mayen | ||||||||
| Port of return | Immingham, United Kingdom | ||||||||
| Purpose | Research | ||||||||
| Objectives | The cruise, which was part of the International Polar Year programme, investigated evidence for the existence of methane hydrate in the sediment of the continental margin of northwestern Svalbard, and evidence for the escape of methane gas released by the hydrate into the water column during the period following the last glaciation to the present day (approximately 15,000 years). It used geophysical and geological techniques to detect methane hydrate beneath the seabed, discovered and sampled features through which methane escapes to the seafloor, and measured methane concentration in the water column and the atmosphere.
The seabed was imaged and mapped using multibeam sonar (Simrad EM120), Simrad EK60 echo sounder, TOBI deep-towed sidescan sonar (30 kHz), and Widescan sidescan sonar (100 and 325 kHz). The sedimentary layers and geological structures beneath the seabed were imaged with the 7kHz profiler in TOBI, a TOPAS sub-bottom acoustic profiler and multichannel seismic reflection (96 channels with 6.25-metre group spacing) using two GI guns in true GI mode 45/105 cu. In. More accurate information on seismic velocity will be obtained by deploying 4 ocean-bottom seismometers on the seabed for two or three days at a time. Samples of sediment, two of them containing hydrate, were taken, using piston corer, gravity corer and box corer. Water chemistry was measured from samples taken with bottles attached to ctds and continuously from the ship using the uncontaminated seawater supply. Air samples were taken. | ||||||||
| Chief scientist | Graham K Westbrook (University of Birmingham School of Geography, Earth and Environmental Sciences) | ||||||||
| Project | IPY - Gas Hydrates | ||||||||
| Cruise report |  (126.75 MB) | ||||||||
| Ocean/sea areas | |||||||||
| General | Arctic Ocean | ||||||||
| Specific | Arctic Ocean | ||||||||
| Track charts | (4.79 MB) | ||||||||
| Measurements | |||||||||
| Physical oceanography | |||||||||
| Surface measurements underway (T,S) | Quantity: track kilometres = 6437 Description: Underway measurements of temperature, salinity | ||||||||
| Water bottle stations | Quantity: number of stations = 13 Description: 24-bottle rosette | ||||||||
| CTD stations | Quantity: number of stations = 13 Description: CTD | ||||||||
| Chemical oceanography | |||||||||
| Other chemical oceanographic measurements | Quantity: number of measurements = 1100 Description: Flux of methane and carbon dioxide from surface seawater to air, using an automated equilibrator and Gas Chromatograph | ||||||||
| Meteorology | |||||||||
| Atmospheric chemistry | Quantity: number of measurements = 1100 Description: Flux of methane and carbon dioxide from surface seawater to air, using an automated equilibrator and Gas Chromatograph | ||||||||
| Atmospheric chemistry | Quantity: number of samples = 83 Description: 5-litre samples of air taken to measure methane concentration. | ||||||||
| Geology and geophysics | |||||||||
| Core - soft bottom | Quantity: number of cores = 33 Description: 16 box cores, 15 gravity cores, 2 piston cores | ||||||||
| Single-beam echosounding | Quantity: track kilometres = 5300 Description: SIMRAD EK60 multi-frequency single-beam sonar (echo-sounder), SIMRAD TOPAS parametric sub-bottom profiler | ||||||||
| Multi-beam echosounding | Quantity: track kilometres = 5300 Description: SIMRAD EM120 multibeam echo sounder | ||||||||
| Long/short range side scan sonar | Quantity: track kilometres = 249 Description: TOBI 30 kHz deep-towed sonar with maximum total swath width of 6 km | ||||||||
| Long/short range side scan sonar | Quantity: track kilometres = 58 Description: Widescan 100 and 325 kHz deep-towed sonar with total swath widths of 200, 400 and 800 m | ||||||||
| Multichannel seismic reflection | Quantity: track kilometres = 1180 Description: Streamer: 96-channel, 6.25-m group spacing, Two GI guns 45/105 cu. in. | ||||||||
| Other geological/geophysical measurements | Quantity: number of deployments = 13 Description: 13 4-component (hydrophone and 3 orthogonal geophones) ocean-bottom seismometers deployed at 5 locations. | ||||||||
| Data held at BODC | Get data | ||||||||
| Series/Profiles | |||||||||
| 1 Single-beam echosounder | Reference numbers Horizontal spatial co-ordinates Bathymetry and Elevation
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| Discrete samples | |||||||||
| 65 Atmospheric air sampling pump | Concentration of alkanes in the atmosphere Stable isotopes in the atmosphere | ||||||||
| 16 Box core | Concentration of aliphatic hydrocarbons in sediment samples Trace metalloid and inorganic selenium concentrations in sediment pore water Concentration of inorganic sulphur species in sediment pore water Sediment water content, porosity and surface area Dissolved concentration parameters for other gases in sediment pore waters Carbonate chemistry in sediment pore waters Concentration of inorganic halogens in sediment pore waters Metal concentrations in sediment pore waters | ||||||||
| 13 CTD frame plus rosette sampler | Dissolved oxygen parameters in the water column Concentration of alkanes in the water column | ||||||||
| 15 Gravity Corer | Concentration of aliphatic hydrocarbons in sediment samples Trace metalloid and inorganic selenium concentrations in sediment pore water Concentration of inorganic sulphur species in sediment pore water Stable isotopes in sediment Sediment water content, porosity and surface area Dissolved concentration parameters for other gases in sediment pore waters Carbonate chemistry in sediment pore waters Concentration of inorganic halogens in sediment pore waters Metal concentrations in sediment pore waters | ||||||||
| 2 Piston corer | Concentration of aliphatic hydrocarbons in sediment samples Trace metalloid and inorganic selenium concentrations in sediment pore water Concentration of inorganic sulphur species in sediment pore water Sediment water content, porosity and surface area Dissolved concentration parameters for other gases in sediment pore waters Carbonate chemistry in sediment pore waters Concentration of inorganic halogens in sediment pore waters Metal concentrations in sediment pore waters |
