Why is the atacama desert dry
The Atacama Desert
hello everyone this is mr. Frasier again
gotta give you a quick tutorial here I
want to remind you before we begin that
these are unscripted and because of that
I sound silly and sometimes make
mistakes but that's the fun of it so
today we're going to talk about really
quickly the Atacama Desert which is one
of my favourite topics to discuss the
Atacama Desert is found on the west
coast of the Andes Mountains along the
Pacific Ocean and stretches for about
600 miles from Peru southern border into
northern Chile and it sits you can think
of it kind of in the the western hump of
South America now the the Atacama Desert
sits along the ocean which may be
surprising to you because you assume the
water from the ocean you'd have a moist
climate but we just don't have that in
fact the Atacama Desert we consider an
absolute desert and it's called the
absolute desert because it is the driest
place on earth there's spots there that
have never ever received rain since
human beings have been recording it it's
extremely that dry and nothing is
naturally living in most of this desert
and and this is what makes it unique
even though it's not the biggest desert
in the world
the Atacama Desert is by far the driest
so what makes it so dry is this thing
called a raining shadow the Andes
Mountains and the wind patterns coming
off both the Atlantic in the Pacific
Ocean are shadowing out this area of
land and creating an inability of water
to be dropped there so let's take a look
at what that means if we look at the
desert here we'll notice that the Andes
Mountains stretch along this here
there's all the Andes and then the
Atacama sits in this area right here you
have the Pacific Ocean here
and then obviously you have the lower
lying regions of South America to the
east the rainshadow is easier understood
if we look at it from the side coming
first from the east we'll talk about the
winds with them carrying moisture coming
off the Atlantic Ocean blow in a
westerly direction and there's a few
constants we need to know about weather
and one of those is as clouds go higher
and altitude they cool because you
become colder as you become further away
from or a surface as these clouds cool
they do what's called condensate and
they actually will release their
moisture in the form of rain or snow or
whatever precipitation is is the
conditions are right for so coming off
of the Atlantic Ocean
these these winds pull all that moisture
from the continent and from the ocean
and they're very quickly pushed up
against the Andes Mountains which as we
all know from it pressure and and those
kinds of activities the heart of their
push the faster they move the faster
they move the more moisture is dropped
and so basically what we have is up
until the tip of the mountains we have
most of the moisture being dropped from
the on the eastern side of the continent
if these clouds can make it up over the
Andes Mountains they because of the the
absence of land the absence of pressure
will actually begin to drop but when
they drop the opposite happens from what
we discussed earlier the temperature
gets warmer and these clouds in effect
stop or cease dropping their moisture
they actually dry up so no rain will
come from the eastern side of these
Andes Mountains due to this low pressure
I'm sorry high pressure
from coming over the mountains so you
may look at it and say what would about
from the West when we look at it from
the West
those few wins which would come from the
ocean are unable to pick up moisture the
reason they cannot pick up moisture from
the ocean is that the ocean in this
region of the world is particularly deep
and cold because the water the moisture
in the water is so cold
these winds do not pick up the moisture
and therefore their dry winds and so
even though they are being pushed up
here there's no moisture to drop within
those clouds and so the Atacama Desert
is left to dry and left without without
the rainwater that we would need to
support life there's another look there
so that doesn't mean that humans don't
want to use this dry region in the earth
because even without life the desert
does serve a purpose the first one I
want to talk about is this thing called
saltpeter saltpeter is an agreement and
Explosives it's been used for centuries
and things like gunpowder and it's
incredibly important to the mining of
silver tin and copper in the Andes
region so saltpeter is actually taken
out of this desert because of the dry
conditions it's plentiful because it
doesn't wash away like in other regions
it's easier to find easier to preserve
because there's no water damage the
other reason why people are using the
Atacama Desert is is observatories these
are the institution's the the buildings
which house the massive telescopes which
look at the stars and study space the
reason the desert is perfect for this is
because there's little light pollution
and little actual pollution in the air
above this region - like a better word
mess up these
visual of the scientist so the desert is
a perfect place for people like those
people at NASA to set up their
telescopes and to watch the universe so
people are living in this desert so how
do they live in the Atacama well the
first thing they need is water water and
food have to be trucked in now the
problem with trucking water in it is
twofold for the first one is it causes a
lot of pollution the that's the exact
reason why people are in the Atacama
using the resources and so it puts it
the danger that the other problem
besides me I'll write it down here
besides pollution is a lack of support
resources so for example there's not a
gas station if somebody breaks down in
the desert there's not a rest area for
these men and women to pull over at and
so it's incredibly difficult and
expensive to truck this water and in
this food in so modern science has
brought a solution to surviving in the
Atacama Desert and that's what you're
gonna do next you're going to watch the
video that is below on the website and
I'd like you to watch carefully as you
see these people literally bring life to
the desert through science you're gonna
watch that and then you're gonna answer
the two questions that are below good
luck thank you for watching
