RRS James Cook JC109
Cruise summary report
| Cruise Info. | |||||||||||||
| Ship name (ship code) | RRS James Cook (740H) | ||||||||||||
| Cruise identifier | JC109 | ||||||||||||
| Cruise period | 2014-10-11 — 2014-11-05 | ||||||||||||
| Status | Completed | ||||||||||||
| Port of departure | Southampton, United Kingdom | ||||||||||||
| Port of return | Port of Spain, Trinidad and Tobago | ||||||||||||
| Purpose | Research | ||||||||||||
| Objectives | The primary purpose of this cruise was to recover an array of 25 ocean-bottom seismographs, which had been recording passive micro-seismicity data at the 13° 20'N oceanic core complex on the Mid-Atlantic Ridge since they were deployed during JC102 in April 2014. This array of seismographs was recording local seismic events associated with extension-related slippage on the fault planes that accommodate spreading at this plate boundary. The data will be used to test models of plate accretion at slower spreading rates. This cruise is the second of three: i) passive array deployment; ii) passive array recovery; and iii) active source seismic imaging, coupled with Autosub near-seabed geophysical and oceanographic surveying. This cruise comprised a transit to the work area of ~11.5 days, ~2.25 days of OBS recovery, 3.25 days of swath bathymetry data in-fill in the work area and a transit from the work area of ~5 days - a total of ~22 days. Four days were lost to a delayed departure from Southampton due to rectification works on and recertification of the lifeboats and HMRC custom clearance. Swath bathymetry and gravity data were acquired throughout the transits to/from ports as well as in the study area. | ||||||||||||
| Chief scientist | Christine Peirce (University of Durham, Department of Earth Sciences) | ||||||||||||
| Cruise report |  (9.50 MB) | ||||||||||||
| Ocean/sea areas | |||||||||||||
| General | North West Atlantic Ocean (limit 40W) | ||||||||||||
| Specific | Mid-Atlantic Ridge | ||||||||||||
| Track charts | (0.21 MB) | ||||||||||||
| Measurements | |||||||||||||
| Geology and geophysics | |||||||||||||
| Geophysical measurements made at depth | Quantity: number of stations = 1 Description: Sound velocity measurement from surface to 1000m depth - using dual Valeport Midas sound velocity probes | ||||||||||||
| Single-beam echosounding | Quantity: activity duration in days = 22 Description: Single beam bathymetry - using a Kongsberg EA600 12 kHz | ||||||||||||
| Multi-beam echosounding | Quantity: activity duration in days = 22 Description: Multibeam bathymetry - using an Kongsberg EM120 in deep mode 191/191 beams, maximum angle 70°/70°, beam width 7000m/7000m in good sea conditions | ||||||||||||
| Seismic refraction | Quantity: number of deployments = 25 Description: Ocean-bottom seismograph (OBS) | ||||||||||||
| Gravity measurements | Quantity: activity duration in days = 22 Description: Gravity - using a LaCoste Romberg sea gravity meter (instrument S-040) | ||||||||||||
| Other geological/geophysical measurements | Quantity: activity duration in days = 198 Description: Passive seismicity data - using ocean-bottom seismographs, comprising 3-component geophones and either a hydrophone or differential pressure gauge as sensors | ||||||||||||
| Data held at BODC | Get data | ||||||||||||
| Series/Profiles | |||||||||||||
| 1 Meteorological data logger | Reference numbers Horizontal spatial co-ordinates Air pressure Visible waveband radiance and irradiance measurements in the atmosphere Date and time Wind strength and direction Raw light meter output Air temperature Solar Radiation Atmospheric humidity Reference numbers Horizontal spatial co-ordinates Air pressure Visible waveband radiance and irradiance measurements in the atmosphere Date and time Wind strength and direction Raw light meter output Air temperature Solar Radiation Atmospheric humidity
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| 1 Multi-beam echosounder | Reference numbers Horizontal spatial co-ordinates Date and time Platform or instrument orientation Horizontal platform movement Bathymetry and Elevation Reference numbers Horizontal spatial co-ordinates Date and time Platform or instrument orientation Horizontal platform movement Bathymetry and Elevation
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| 1 Multiple instrument types | Reference numbers Horizontal spatial co-ordinates Transmittance and attenuance of the water column Date and time Salinity of the water column Temperature of the water column Raw fluorometer output Electrical conductivity of the water column Metadata parameters Raw suspended particulate material concentration sensor output Chlorophyll pigment concentrations in water bodies Reference numbers Horizontal spatial co-ordinates Transmittance and attenuance of the water column Date and time Salinity of the water column Temperature of the water column Raw fluorometer output Electrical conductivity of the water column Metadata parameters Raw suspended particulate material concentration sensor output Chlorophyll pigment concentrations in water bodies
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| 2 Sound Velocity Probe | Reference numbers Sound velocity and travel time in the water column Vertical spatial coordinates Temperature of the water column Reference numbers Sound velocity and travel time in the water column Vertical spatial coordinates Temperature of the water column
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| Discrete samples | |||||||||||||
| 2 Sound Velocity Probe |
