RRS Charles Darwin CD144

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Charles Darwin (74AB)
Cruise identifierCD144
Cruise period2003-01-13 — 2003-02-22
Port of departureMuscat, Oman
Port of returnVictoria, Seychelles
ObjectivesThe primary aim of the project was to collect 2D controlled source, deep seismic data at near-normal and wide-angles of incidence along a transect across the entire reconstructed Seychelles-Laxmi Ridge plate margins. 32 Ocean bottom seismometers/hydrophones, a 2.4 km long 96-channel streamer and 14-gun array were used. Supplementary gravity, magnetic and bathymetry was also collected. Following the cruise, the data will be processed and inverted to determine the seismic velocity structure of the crust and uppermost mantle. This will enable the strain and magmatism distribution across the whole rift to be determined.
Chief scientistJennifer S Collier (Imperial College London Department of Earth Science and Engineering)
Ocean/sea areas 
GeneralArabian Sea
SpecificArabian Sea, North Seychelles
Track chartsRRS Charles Darwin CD144 cruise track — cd144trk.pdf (0.02 MB) 
Physical oceanography 
BathythermographQuantity: number of profiles = 4
Description: Sippican T7 (max depth 780 m) XBTs
BathythermographQuantity: number of profiles = 8
Description: Sippican T5 (max depth 1830 m) XBTs
Other physical oceanographic measurementsQuantity: number of profiles = 2
Description: Sound velocity probes
Geology and geophysics 
Single-beam echosoundingQuantity: activity duration in days = 35
Description: 12 kHz and 3.5 kHz Precision echo-sounding
Multi-beam echosoundingQuantity: activity duration in days = 38
Description: EM12 swathbathymetry
Multichannel seismic reflectionQuantity: track kilometres = 2400
Description: 96-channel, MCS
Seismic refractionQuantity: track kilometres = 1200
Description: OBS/OBH/Disposable sonobuoys
Gravity measurementsQuantity: activity duration in days = 38
Description: Gravity (LaCoste and Romberg marine gravimeter)
Magnetic measurementsQuantity: activity duration in days = 38
Description: Magnetics (proton procession magnetometer)
Moorings, landers, buoys 
Geology and geophysics 
Dredge3° 34' 0" S  56° 12' 0" E — Deep water dredge in 3200 m of water on the western edge of a 400 m high seamount. Hard rocks recovered.
Dredge3° 7' 0" S  56° 13' 0" E — Deep water dredge in 3900 m of water on the south-western edge of a 600 m high elongate seamount. Hard rocks recovered.