!
.
.
,.
232
THE SEAS
'
,
(page 229) with a result that a current ows out through
the Straits of Florida, the Gulf “
Stream.”_
On reaching
more northern latitudes, however, the driving force on the
Gulf Stream ceases to be a difference in water level, but it
,
is now sucked in towards the ice in polar regions and
considerably aided by persistent South—West winds which
drift the surface water along in -a North—Easterly direction,
so that the waters that bathe our coastS are more correctly
_termedthose of’the North Atlantic “ Drift ” than the
Gulf
Stream.
_
,
.
_
These types of water movement, drifts and currents,
are to be found always around our coasts.
There is for
instance a prevalent drift of surface water up the EngliSh
Channeland through the Straits of -Dover into the North
.
Sea.
In fact “ drift bottles” (Le. special bottles used for
measuring water movements [see page 2571) liberated in
the western end of the English Channel have been known
to travel in the surface drift on to the Swedish and Nor—
wegian coasts in just over a hundred days, a distance of
about 700 miles.
One indeed was picked up on the north
shore of Norway after having travelled a distance of 1,440
miles at a speed of about 76 miles a day.
In these -'
_
_
instances, however, there was no actual movement of water
mass at anything approaching this speed:
When a strong wind has been blowing for some days on.
to the shore, thesurface water then becomes piled up on
the shore on Which the wind is blowing with the result
that a head of water is produced and water ows outwards
:
in the deeper layers to réplace the Water that has been
driven in by the wind (Fig. 48).
'
,
_
_
There remains one other type of water movement, and
.
this is movement of bodies of water in
direction,
either upwelling or sinking,
Sinking. water masses are
produced in various ways, such asin the case of water of a
-
.
.
.
,.
232
THE SEAS
'
,
(page 229) with a result that a current ows out through
the Straits of Florida, the Gulf “
Stream.”_
On reaching
more northern latitudes, however, the driving force on the
Gulf Stream ceases to be a difference in water level, but it
,
is now sucked in towards the ice in polar regions and
considerably aided by persistent South—West winds which
drift the surface water along in -a North—Easterly direction,
so that the waters that bathe our coastS are more correctly
_termedthose of’the North Atlantic “ Drift ” than the
Gulf
Stream.
_
,
.
_
These types of water movement, drifts and currents,
are to be found always around our coasts.
There is for
instance a prevalent drift of surface water up the EngliSh
Channeland through the Straits of -Dover into the North
.
Sea.
In fact “ drift bottles” (Le. special bottles used for
measuring water movements [see page 2571) liberated in
the western end of the English Channel have been known
to travel in the surface drift on to the Swedish and Nor—
wegian coasts in just over a hundred days, a distance of
about 700 miles.
One indeed was picked up on the north
shore of Norway after having travelled a distance of 1,440
miles at a speed of about 76 miles a day.
In these -'
_
_
instances, however, there was no actual movement of water
mass at anything approaching this speed:
When a strong wind has been blowing for some days on.
to the shore, thesurface water then becomes piled up on
the shore on Which the wind is blowing with the result
that a head of water is produced and water ows outwards
:
in the deeper layers to réplace the Water that has been
driven in by the wind (Fig. 48).
'
,
_
_
There remains one other type of water movement, and
.
this is movement of bodies of water in
direction,
either upwelling or sinking,
Sinking. water masses are
produced in various ways, such asin the case of water of a
-
.