Hi everybody! Today with NASA and Earth Observatory for Kids we're gonna be
talking about Earth's most abundant resource. Can you guess it? You may have
heard of the Earth being referred to as the Blue Marble or Water Planet because
of how much water it has on it. If you were to take all of the water on the
Earth's surface and put it into a cup with all of the surface that's covered
by land you would have something that looks like this. You'd have about one
fourth of Earth being covered in land and the other 3/4 all being just water. Now that is a
lot of water! Especially when we consider how much time we actually spend on dry
land. But even though Earth is covered in mostly water, how much of it is actually
drinkable? Did you know that only 2.5 percent of Earth's water is actually
fresh? The rest is salty (hmmm spit) undrinkable yuck! And all of the 7 billion people
that are on the planet, not to mention all the birds, bears, bees, and all of
those other creatures that rely on water, also have to share that water, and our
crops and even our flowers rely on that water too. So where do we find fresh
water on earth and how do we monitor it? Satellites provide us with views of
fresh water from space and NASA uses the data from these satellites to monitor
our own fresh water supply. These images show us just some of the ways that fresh
water is stored on land and in the Earth. EO Kids: Water, Water Everywhere! You can
explore some of the cool places where we find fresh water on Earth. And speaking
of cool, when it's cold enough water becomes a solid that we know as ice or
snow. Bow this fresh water can be found on
glaciers or covering the mountaintops. But that snow
isn't exactly something that you can drink. In this image of Greenland you can
see a really big glacier called an ice sheet. And then in this image, this is
permafrost where we actually have water frozen into the soil. And this satellite
image of Siberia shows the lakes that are created when some of that water in
the permafrost actually melts. But satellites also search for water vapor.
Now we can't see much that's in our sky because it's filled of a lot of really
small gases and particles. But one of those gases, water vapor, when it gets to
be condensed enough form something we can see and satellites can see - and
those are clouds. So those clouds are really important
also in the fresh water supply, especially when those clouds become
cumulonimbus clouds or nimbostratus clouds which are responsible for
bringing that rain down to the ground. Here is an image from the the Amazon
rainforest which shows some of those clouds hanging out in the sky above.
Although these clouds are cumulus clouds not cumulonimbus clouds, so believe it or
not, it wasn't raining in the rain forest on this day. But fresh water is also found
in lakes and rivers as the rain and snowmelt collect in the lowest parts
of the land, in those valleys, forming those lakes.
This is Lake Baikal, which is the world's largest and deepest lake and is found in
Russia. But one last place where freshwater is found, but it's not very
obvious, and it's also really important, but it's in the ground. Water can be
found seeping through the space between gravel, dir,t and sand. This water, known as
groundwater, can even be found in dry places like the deserts. In this image,
farmers in Saudi Arabia can tap into aquifers below the sandy surface to
access groundwater that is used to water those plants, even there in the middle of
the desert. So, you can see those as the circular crops from the
center-pivot irrigation. So now that you know all about how NASA looks at ground
water and all that fresh water from space, we have some groundbreaking news!
We are going to make a model aquifer. A model aqua-what? An aquifer. So some of
Earth's fresh water, ground water, is stored in underground reservoirs called
aquifers. Rain and snowmelt seep into the ground until it reaches a layer of rock
and soil that can hold the water and then the water is stored in those spaces
between the rock and soil particles until it's pumped back to the surface
through a well, like the water that's used to irrigate those desert
crops. This activity can be found on the last page of the EO Kids issue, "Water,
Water Everywhere!" As part of the Maker Corner, make your
own model aquifer. So first I need to gather all of my materials. First, I need
a two-liter bottle that I'm going to cut into two parts. I also need the scissors
that I used to cut that material and then I also need some water, an ice cube -
if one's available - a clean spray bottle, that has a nozzle like this - with the
straw attached. And I also need some
soil, some sand, some pebbles, and some rocks. In addition, I'm gonna need some
marbles and a piece of cheesecloth or just an old dishrag that you can cut a
little piece out of. I just cut this little circle, like that. So we are going
to make our own model aquifer and to do that today I am going to be joined by my
assistant. Hi! So today I have my assistant; this is Lily who is an EO Kids
enthusiast and also my assistant for the day. So Lily, first thing I'm going to do
in making our model aquifer is cut this 2-liter bottle into two separate parts.
Do you think you can do that for me? All right go ahead. Sike! I already did
it for you.
So make sure that you get a scissors, cut carefully, and I just wanted
to make sure that this was already done because it could kind of be a little
tedious and take a little bit of time. The next step is to take our marbles -
you're going to fill the bottom part. When you go ahead and dump those in to
here, so you fill at the bottom with our gems and our marbles. Pretty! And then
the next thing we're gonna do is, we're going to take the top of our two-liter
bottle, we're going to turn it upside down, and set it on the inside. So go
ahead Lily you want to do that step. Perfect! Nicely done.
Alright, and then our next step is to take our nozzle from our spray bottle
and we're gonna slide that in between (whoops!),
slide that in between the top of the bottle and the bottom, so that it goes
right into those marbles. Cool! and got it in there. Awesome, thank you!
and the following stuff is to take this little cheesecloth
and stick that down in the bottom so that we cover - we need to stick it down
there, can't leave it open so that it looks kind of like a funnel without a
bottom in it. Can I show you? All right, so this can be a little tricky. So what we
have here is, I made a circle. What I like to do to make it a little easier is to
fold my circle kind of like so and turn it into a little bit of like a cup and
then take this little cup and just slip it right down in there. Perfect, and
that way when we fill up our container we won't lose any of the soil and rocks
and pebbles that we're putting in there because it'll all be caught by our
little cheesecloth stopper. All right, so the next thing that we need to do is to
put some rocks in the bottom on top of that. So go ahead and open those rocks
slowly, and we are going to put them inside our aquifer. So this is supposed
to be kind of like the ground. So our ground, our earth, it's made up of a bunch
of layers of different types of sediment. So go ahead and put those rocks in there.
You don't have to put all of them in there, but you can take a few handfuls
and just kind of put them in the bottom. So this is kind of like the rocks that
are underneath our grass that are a little bit further down. All right so,
you've got a nice layer of rocks right there that you can see and then the next
thing we're gonna do is we're gonna add a layer of sand. So Lily, can you grab
the bag of sand that you collected earlier from our sandbox for me? Thank
you for doing that, and pour just about half of that bag into here. Can you do
that? Awesome good work! Keep going, just a little bit more. Good work. All right, that's
probably good. Now we have rocks at the bottom. You
can't see those anymore and then sand on top of those rocks. The next thing that
we're gonna put in there is some pebbles. So, Lily, can you grab our white pebbles? So
that you guys can see, that may be a little bit easier, and throw in a couple
handfuls of those. Awesome, thanks so much. Why don't we do about four handfuls of
those. Nice, perfect! So now we've got all those layers. All right, and now we get to
add another layer of sand. So you can go ahead and empty out the rest of that
sand into a container? Looks like we also picked up a few pine needles with it,
which is totally normal because you know our soil is made up of a bunch of
decomposing pieces of plants and other material. So, in this case, our
ground is gonna be made up of a little bit of pine needles. Right and then the
last layer is our soil layer. So that's going to be the top layer. So we are
going to dump some soil in there. All right, you ready? And here goes the soil.
Our soil is a very fine soil, which is very silty and is also called clay. Yeah
that's plenty, thank you. Be careful not to spill, or do it in a
place where it's okay if you do. So I can just show you here we've got our all of
our layers in there. That's the pebbles, that are starting to be harder to see, but
that's because a lot of those finer soils and sands fill in a lot of those
cracks. But there's something else that can fill in those cracks too.
So, the last thing that we're gonna do is we are going to pour some water over the
top of this, like it's rain. If you have ice cubes you could also put ice on top
as though it was like an ice sheet or possibly a glacier or maybe snow even.
But what we're gonna do is we're gonna, we're gonna make it rain. So Lily, can you
make it rain over? All right. So it's been raining. Rain, rain, go away, come again
another day. All right. Oh our soil (whoo) it was experiencing a
little bit of a flash flood there. See how it's just sitting all on top? And that's
because we don't have a very permeable soil. That silty, clay like soil actually
acts a lot like a barrier preventing water from seeping through. But as it
sits here for a little bit it'll start to actually make its way through. Can you
see down here? it's getting darker and darker as the water goes through. Yep,
maybe you can see that too - darker and darker as the water goes through. And now
we wait. We are going to wait until all of that
water seeps down. And where do you think it's going to end up? Lily, where do you think
it's gonna end up once it seeps all the way through? At the bottom. At the bottom, yeah in all of
those marbles that we put in, right. That's kind of like our aquifer. So when the
water seeps through all those spaces it ends up in an area that fills in the
spaces between rocks and soil and those are the aquifers that we use to pump
water out of the ground to be able to irrigate a lot of our crops or to
provide fresh water in areas where there isn't a source readily available on the
surface. Oh there it goes! You can see that our water is coming through. Okay,
but once that water is down in our aquifer how do you think we get it out
Lily? You can use your pump . That's exactly right.
So this pump will help us get all of the water back out so that people or plants
or animals can use it. So this is how you would make a model aquifer now one other
thing that I think is pretty cool is that you can turn this into a terrarium.
And I know somebody was really excited about making a terrarium today. So when
you get to this point you can also plant seeds in the top of it.
And if you water them daily and pump your extra water out when it gets to be
too much - I don't think we have enough water in there yet - maybe we should make
it rain again. Can you make it rain for us Lily? All right, here comes our
cumulonimbus cloud (whew) it's a rainy day. But we can keep that soil moist and
allow those plants to sprout and grow. So there you go. You may have a planter. You
can also have a model aquifer. And another way you can use it, is by putting a piece
of string at that bottom before you put in that cheesecloth and it will actually
wick water up into your ground and water those plants for you too. So you can make
a self-watering machine. So, if you want to do this experiment and others with EO
Kids, check out the link and download the article along with the activity and get
started exploring Earth! Thanks a lot for joining.