Unit 2- Earth's Systems 1. The Atmosphere 2. The Lithosphere In this class, we will learn about 4 specific systems that make up the Earth. 1. The Atmosphere 2. The Lithosphere 3. The Hydrosphere 4. The Biosphere Now, there are more “spheres” that you can study in & around the Earth, like the magnetosphere or ionosphere, but we'll focus on these 4 basic ones. Image is from the following website: http://apod.nasa.gov/apod/ap980129.html 1

The Atmosphere • The atmosphere is ALL THE GAS that is surrounding the Earth. This includes the air that you breathe. • Scientists split the atmosphere into different layers. Depending on who you ask, there's between 4-6 layers. We'll talk 2nd semester... • Extends 100's of kilometers above the planet. Images are from the following website: http://liftoff.msfc.nasa.gov/academy/space/atmosphere.html Atmo means “vapor”, so this is the sphere of (water) vapor. 3

The Atmosphere • Many different gasses are found in the Atmosphere. Check out this graph.... • Most abundant gas is... • Second most abundant is... • Others include Water Vapor Carbon Dioxide Argon Images are from the following website: http://liftoff.msfc.nasa.gov/academy/space/atmosphere.html Atmo means “vapor”, so this is the sphere of (water) vapor. 4

The Lithosphere • Lithosphere is talking about the crust of the Earth and also the part of the Earth that is right under the crust that is called the Mantle. • There are other parts of the Earth under that, but we'll talk about it 2nd semester... Image is from the website: http://ess.geology.ufl.edu/ess/Introduction/Geosphere.html 5

The Lithosphere • The land that makes up all the continents on earth is called CONTINENTAL CRUST. It is pretty thick, like 40-50 kilometers. • There is also crust on the floor of the ocean called OCEANIC CRUST. This is a bit skinnier, between 10-20 kilometers thick.

The Lithosphere • The Lithosphere is always in motion, but it is very gradual and usually takes hundreds to thousands of years to notice. The movement of the Earth's crust is known as PLATE TECHTONICS. Again, we'll get more into detail 2nd semester with that. Image is from the website: http://ess.geology.ufl.edu/ess/Introduction/Geosphere.html 7

The Hydrosphere • The Hydrosphere is ALL THE WATER on the planet Earth. Not just liquid water, either. • Most (as in 97% or more) of Earth's water is in the Oceans. Most of the freshwater on Earth is frozen in glaciers and ice caps. Only a super tiny fraction of Earth's water makes up lakes + rivers. Image is from the website: http://water.tamu.edu/watercycle.html Hydro means “water”, so this is the sphere of water. 8

• Earth's water is always transferring from place to place • Earth's water is always transferring from place to place. You probably learned about the movement of water – THE WATER CYCLE – in middle school. Here's a picture to help you remember.

The Biosphere • “Bio” means living, so the biosphere includes ALL LIVING THINGS on Earth. All types of organisms are included: Archaea, Bacteria, Protists, Fungi, Plants, Animals. The places on Earth that are occupied by living things are called BIOMES. Image is from the following website: http://www.geology.ufl.edu/Biosphere.html Bio means “life”, so this is the sphere of life. 10

Remember: Earth's Systems are COMPLICATED and we still don't know everything about them. The Earth has been around for BILLIONS of years!!!Modern humans? Only a few thousand... Everything you'll ever need to know about the planet Earth – This video does a good job of summarizing. https://www.youtube.com/watch?v=JGXi_9A__Vc

Earth's Systems Interconnected Earth systems are INTERCONNECTE D – that means that they all have an effect on each other. Activity: As a class, let's come up with some example of how one “Sphere” can impact the others. The Earth system refers to the fact that we use models to look at parts of the Earth, helping us to describe what has happened in the past, what is currently happening, and what might happen in the future. 12