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141
turn north in the western part of the trench, and some water
may pass across gaps in the Greater Antilles Outer Ridge east
of 65°W to become part of the eastward flow on the north
flank. Some flow of warmer water from the Silver Abyssal
Plain southeast across the outer ridge sill at 21°N lat.,
68°W long. is also indicated.
Over the western sector of the Greater Anti 11 es Outer
Ri dge the col dest water on the four trans verse profi 1 es
(Fig. 6.2) is 1.52 to 1.540e, and it lies exclusively north
of the crest at depths greater than 5200 m. This water may
have an eastern source north of the outer ridge. However,
water thi s col d is found in the Puerto Ri co Trench, and it
may move to the north across depressions in the outer ridge -\
i ;
east of 65oW.
One station (AIl Sta. 1825) at the northwest tip of the
Greater Antilles Outer Ridge was unique in that the .potential
temperature never dropped below 1.800e(Section 1, Fig. 6.2).
All five temperature readings in the bottom 150 m were 1.800e,
and the salinities ranged from 34.8840/00 to 34.886°/00.
Although these salinities are .004 to .0060/00 fresher than
Worthington and Metcalf's (1961) curve, they are in close
agreement wi th the other ATLANTIS I I observati ons. Consi stent
thermometric depths from four unprotected thermometers in the
bottom 400 m eliminate any possibility that the deep part of
the cast tripped improperly, and the calculated depth for the
deepest thermometer was 8 m above the sea floor at 5496 m. \
)