SEA WATER
241
'
,
-
'
In the polar regions the surface of the sea is frozen.
When the surface water freezes— itdoes not usually attain
a greater thickness than Seven feet in a year.
When rst
formed it is known as “ oe ice ”
(Plate 84).
Cracks in
the ice, widening into lanes, cause the separation of the
ice into oes which drift at the mercy of*wind and current.
Under certain conditions these oes become driven together
and under the great pressure they become packed together
to forma mass with uneven surface, oes becoming til_t‘ed
”up on end and forced half out of‘the Water, the
presenting an appearance of jumble and disorder.
Such
ice is known as “
pack ice ” (Plate 84).
,
’
,
In the open ocean,
often far from polar regions,
“
ice—
bergs
”
are
met with (Plate 86); These are in no way
connected with the oe or
but are derived from
glaciers.
The majority of those met with in the North
_
Atlantic come from the great glaciers of Greenland.
These
,
solid rivers of ice ow slowly' into the sea, where partly
_
by wave action, and partly by uneven adjustments of
weight, great masses break off to form the icebe'rgs.
The actual process of breaking ofÏ is known as the “ calving
of an iceberg.”
_
-
_
These castles of iCe, biten fantastic in shape, oat down
into the Atlantic. on the Labrador Current, a menace to
passing shipping.
Only a small portion of the mass ofice
is Visible above water, as it oats with_almost eight—ninths
submerged.
_
.
Recently a new method has been tried for destroying these
oating perils.
A boring is made into the side of
berg
and a charge of “_thermite ” inserted, which, on ignitiori,
'
gives o‘ an intense heat.
After s‘everàl hours the berg
breaks up owing to the uneven stresses and strains set up
241
'
,
-
'
In the polar regions the surface of the sea is frozen.
When the surface water freezes— itdoes not usually attain
a greater thickness than Seven feet in a year.
When rst
formed it is known as “ oe ice ”
(Plate 84).
Cracks in
the ice, widening into lanes, cause the separation of the
ice into oes which drift at the mercy of*wind and current.
Under certain conditions these oes become driven together
and under the great pressure they become packed together
to forma mass with uneven surface, oes becoming til_t‘ed
”up on end and forced half out of‘the Water, the
presenting an appearance of jumble and disorder.
Such
ice is known as “
pack ice ” (Plate 84).
,
’
,
In the open ocean,
often far from polar regions,
“
ice—
bergs
”
are
met with (Plate 86); These are in no way
connected with the oe or
but are derived from
glaciers.
The majority of those met with in the North
_
Atlantic come from the great glaciers of Greenland.
These
,
solid rivers of ice ow slowly' into the sea, where partly
_
by wave action, and partly by uneven adjustments of
weight, great masses break off to form the icebe'rgs.
The actual process of breaking ofÏ is known as the “ calving
of an iceberg.”
_
-
_
These castles of iCe, biten fantastic in shape, oat down
into the Atlantic. on the Labrador Current, a menace to
passing shipping.
Only a small portion of the mass ofice
is Visible above water, as it oats with_almost eight—ninths
submerged.
_
.
Recently a new method has been tried for destroying these
oating perils.
A boring is made into the side of
berg
and a charge of “_thermite ” inserted, which, on ignitiori,
'
gives o‘ an intense heat.
After s‘everàl hours the berg
breaks up owing to the uneven stresses and strains set up