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RRS James Clark Ross JR19990211 (JR39b)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR19990211 (JR39b)
Cruise period1999-02-11 — 1999-03-11
StatusCompleted
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnStanley, Falkland Islands (Malvinas)
PurposeResearch
ObjectivesThe objectives of the cruise were:

1. To image two anomalous ridge sediments, E2 and E9, the former exhibiting a 600m high, narrow, linear ridge known as the 'mermaid's purse', beneath which seismic profiling had previously demonstrated the process of a lens of melt.

2. To locate hydrothermal plumes on the ridge using optical sensors to detect particulates formed at seas floor vents and incorporated into rising plumes.

3. To determine whether a seismic low-velocity zone exists beneath E2, by recording airgun signals using ocean-bottom hydrophones.

4. To obtain representative rock samples on all ridge sediments (in conjunction with previous R/V Polarstern dredging).
Chief scientistRoy Livermore (British Antarctic Survey)
Cruise reportRRS James Clark Ross JR19990211 (JR39b) cruise report jr39b.pdf (5.93 MB) 
Ocean/sea areas 
GeneralSouth Atlantic Ocean
Measurements 
Physical oceanography 
Subsurface temperature and salinity measurementsDescription: A number of CTD casts were made throughout the cruise. No. of measurements not noted.
Current metersDescription: A number of CTD casts were made throughout the cruise. No. of measurements not noted.
Geology and geophysics 
Core - soft bottomDescription: A number of cores were sampled throughout the cruise. No. of cores not noted.
Magnetic measurementsDescription: A number of magnetometer deployments were made throughout the cruise. No. of deployments not noted.