SEA WATER
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Atlantic Drift.
Still bearing to the right it bathes
the
QoaSts of Ireland and then the western coasts of Scotland.
Passing the north of Scotland it meets again that portion
which had been deected near the Labradorcoasts and the
two carry on together to the
of Norway, a small
branchturning south into the North Sea.
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-On reaching Arctic regions this—originally warm surface
water has been coOled down nearly to freezirig point.
It has. howevef still a larger salt content than the water
over which it has been owing, and is therefore heavier
at the same temperature.
It therefore sinks, and then
creeps Slowly backtowards the
as adeep bottom
current Which rises once'more
of the ”equator
to replace the water that is being driven westwards on the
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surface by the trade winds.
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Such in simple outline are the main features “of the
oceanic circulation in the North Atlantic.
In the South
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Atlantic a slightly different circulation exists on account
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of the conguration of the land masses; and the two
,
systems become linked.up in the region of the South and
North Equatorial Drifts.
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In the Pacic, too, there” is a system of oceanic curreirts
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after the manner of that in the Atlantic, the Japan
Current or “ Kuro Shiwo ” corresponding ‘to our” Gulf
Stream.
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In these : great circulati0ns thefe are to be distinguished‘
types of water movement} the “ drifts,” and the
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The dri‘fts are brought about
andare
horizontal mdv6mentS of the surface Waters more ‘or less
in the same direction as.the wind is -blowing.- Currents on
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the Other hand are translocations of bodies of water caused
by a denite head of water; In the Gulf of Mexico such a
head;of -water:is produced in- the manner mentioned above
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