- Place: Loyalty Ridge (New Caledonia)
- Participants:
- Material used:
- Stations list
- Results:
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Abstract
The MUSORSTOM 6 cruise took place from 12 to 26 February 1989, on
the Loyalty Islands Ridge. This ridge, situated on the edge of the
New Hebrides Trench, is an extension of the Norfolk Ridge, and is
separated from New Caledonia by the Loyalty Islands Trench, which is
more than 2000 m deep. On the Ridge itself lie scattered coral
formations, built on volcanic substrata. Running from North-West to
South-East are: Astrolabe Reef, Beautemps-Beaupré Atoll,
Ouvéa Atoll, Lifou Island, Maré Island, Durand Reef,
Walpole Island and Orne Bank.
The camber of the Ridge resulting from the meeting of the two plates
has caused the uplift of the islands and an East-West slope. Thus the
reefs of Walpole Island rise to more than 75 m high, those of
Maré to 138 m, Lifou to 60 m, and the atoll of Ouvéa is
raised only on the eastern coast (46 m).
In the course of MUSORSTOM 6, R.V. "Alis" carried out 102 operations
between Beautemps-Beaupré and Maré: 78 with a
Warén dredge, 18 with a beam trawl, 2 with a Charcot dredge, 3
lines of traps were laid, and one shrimp trawl shot.
The sea-bed of the upper bathyal zone (200-1000 m) is very bumpy and
rocky and there are few areas that can be dredged.
The most interesting collections made during the MUSORSTOM 6 Cruise
were some Gymnocrinus with a very long peduncle, found on a
sea-mount East of Tiga Island, and a small black crinoid belonging to
the Holopidae family which had never before been reported in the
Pacific Ocean although known in the Caribbean and the Azores.
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