hi I'm Maddy have you ever considered
why the sea is salty on average our
oceans consist of about 3.5 percent salt
that equates to a total of 50 million
billion tons of salt in our seas it'll
take a pinch if you were to pile all of
that salt onto the Earth's land it would
create a layer 152 metres high so how
did it get there
well some salts dissolved into the ocean
from rock and sediment on the sea floor
other salts escaped from volcanic vents
did beneath the waves but most of it
comes from the land around us rain water
dissolves minerals and salts from the
rocks on dry land
so as rainwater makes its way down river
it collects more and more salts the
amount of salt in this fresh water is
still tiny about 220 times less than
seawater but it is there and this salt
is then deposited into the sea when the
river has run its course
importantly the salt then becomes more
concentrated in the sea because the
sun's heat distills the water from the
ocean surface leaving the salt client
across the globe 4 billion tons of salt
are deposited into our oceans every year
from rivers so surely our seas must be
getting saltier certainly the oceans
have got a lot saltier since their
primeval beginnings but now just as much
salt is being deposited on the ocean
floor as he is coming from the rivers so
it's reached a general equilibrium
however there are differences in
salinity across the globe towards the
poles seawater is diluted by melting ice
caps and heavy precipitation meanwhile
in areas bordering the equator where
it's hot evaporation rates exceed the
amount of rainfall so water here is much
and there is evidence to suggest that
these differences are increasing as sea
temperatures rise parts of the Atlantic
have already shown great evaporation
rates and with it a rise in salinity
levels this may not seem important but
the more salt in the ocean the greater
its density and the slower it will
circulate meaning that important marine
nutrients won't get distributed around
the globe but interestingly it's not
just your everyday sodium chloride that
is gathered by rainfall and freshwater
systems rivers actually carry and
deposit more calcium than chloride so
why is it our seas aren't full of
calcium it's because living organisms
like mollusks crustaceans and coral use
huge amounts of calcium as various forms
to build their body structure without
this influx of salt and minerals from
our rivers and streams life would
certainly be very different in our
oceans please subscribe to earth
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bye what about a hurricane how much
water is in one of those well they are
huge of have a much higher water density
so much so that their average water
content has been estimated at 50
thousand metric tons we think of our
planet as a watery place the blue planet
70% of the earth's surface is covered in
water and in fact water's unique as the
only natural compound that occurs in all
three states but if we scooped it all up
and sculpted that water into a sphere
how big would that sphere thing