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Brine detection

A brine pool in the Conrad Deep (27N), first discovered by [Ehrhardt and Hubscher (2002)], was proven and could be identified by CTD-data (Stations 4, 5, and 12 in Tab.4). The brine pool is located at the center of the Conrad Deep with a maximum thickness of about 30 m (Fig.16). The sound velocity increases at 1485 m water depth from 1540 to 1780 m/s within a small interface of 1-2m (21). The temperature of the brine is 23.5° C. Light transmission signal is scattered within the brine/seawater interface of about 4 m probably reflecting particles precipitated or settled at the density and redox gradients.

The brine pool in the Oceanographer Deep is also located in the center of a depression at about 26N, E of the Brothers Islets. The thickness of the brine is about 100m and the brine/seawater interface is between 1432 and 1436m water depth. A temperature of 24.9°C and a sound velocity of 1803m/s were measured in the brine and the scattered light transmission was detected at the brine/seawater interface (CTD-6 and 11). A second small bottom near 26.5°C  warm brine layer could be detected in the temperature and transmission profiles from CTD station 11.

Nereus Deep brine was detected at the north-east flank of a depression at stations CTD-9 and -10. The small brine pool shows less dense characteristics (Sound velocity 1780 m/s) and temperatures of 30°C  are comparable to those found about 30 years before [Bignell and Ali (1976)].

The water column was investigated by CTD-measurements at two isolated depressions which are separated from the main basin in the Thetis Deep. No brine could be detected by CTD-measurement (CTD-7 and 8).


next up previous contents
Next: Hydrographic profiles Up: OCEANOGRAPHY Previous: WATER SAMPLING   Contents
2005-11-05