(Intro Music)
 
Sabrina: You know, some things just make sense together. Like peanut butter and jelly, or burgers and fries, or water and... dirt? Okay, let me explain that last one. 
 
So we've already talked about how the Earth is divided into four spheres. That's the hydrosphere, the geosphere, the biosphere, and the atmosphere. Well today I want to focus on just the first two of these spheres, the hydrosphere which includes all the water on the planet, and the geosphere which is simply the solid earth. 
 
The hydrosphere and the geosphere are both equally important and different spheres of our planet, but do they interact with each other? And if so, how?
 
Well, let's have a little refresher on what exactly both of these spheres are separately before we figure out how they interact together. You'll remember that "-Geo" means "Ground." So what we call the geosphere includes all the rocks, minerals, and ground found on and inside the Earth. This means every single pebble in the mountains, every grain of sand in the deserts, the entire ocean floor, and even the continents we live on are part of the geosphere. If it looks like solid ground, it's part of the geosphere. The geosphere includes the surface of the Earth, which we're on now, but it even extends down to the planet's core below us. 
 
Now the hydrosphere is also found on the Earth's surface and just below it too. But the hydrosphere also extends up into the atmosphere. "-Hydro" means "Water," so the hydrosphere is made of all the water on Earth. And I do mean all of the water, like ponds, rivers, lakes, streams, oceans, glaciers on the Earth's surface, but also the moisture in the air, like rain, hail, and snow. That's all part of the hydrosphere too. 
 
So the geosphere and the hydrosphere are separate systems, but if we think of Earth as one giant system, or a group of systems working nicely together, then the geosphere and the hydrosphere are two parts that work together to support life -like you and me- on the planet. How do these two spheres work together though? Let's take a look at a model to find out. 
 
Since the geosphere is the ground, let's start by laying down some of that. And let's throw in some mountains too. Now we need some water. Let's have a river winding through the land about here. How about a lake? And just for the heck of it, let's throw some rain over here. Okay, so you can see in this model some elements of the geosphere, right? That would be the ground and the mountains. You can also see elements of the hydrosphere. Say "Hi" to the river, lake, and raindrops. 
 
But so what? Both spheres are there, but they're not really doing anything together, right? Wrong. Look closer. See that river bed under the river? How about the bottom of the lake? Those things are part of the geosphere. They're parts of the geosphere that are supporting and surrounding parts of the hydrosphere. And check out the rain over the mountains. The rain, which is part of the hydrosphere, is falling on and running down the mountains, which is part of the geosphere. And this is just a really small example of the two spheres interacting. Every day, all over the Earth, water is moving over landforms, from waterfalls flowing down mountains to ocean waves crashing on sandy shores. Water rests in lake beds, or ocean floors, in river valleys, and even in the soil in your backyard. All of which are part of the geosphere. So on a basic level, the geosphere really provides a home for the hydrosphere. Which I think is kind of sweet. But that's just me. 
 
So now you know a little bit about how the geosphere and the hydrosphere are connected. To find out how they can actually affect and even change each other, check out our next episode.
 
(Outro Music)