Spheres • Atmosphere (“air sphere") • Biosphere (“life sphere") • Hydrosphere ("water sphere") • Lithosphere ("rock sphere")
Atmosphere • The envelope of air that surrounds the Earth
Atmosphere • Life on Earth is supported by the ATMOSPHERE, solar energy, and our planet's magnetic fields. • The ATMOSPHERE absorbs energy from the Sun, recycles water and other chemicals, and works with the electrical and magnetic forces to provide a moderate climate. • The ATMOSPHEREalso protects us from high-energy radiation and the frigid vacuum of space.
Composition of the Atmosphere • N2-78% • O2-21% • Other-1% • Argon (Ar) • Water (H2O) • Carbon Dioxide (CO2) • Ozone (O3)
Biosphere • Includes all living things • For example, rainforests in South America, grasslands and forests in North America and whales in the ocean
Hydrosphere • Includes all of the rivers, lakes and oceans on Earth • Here we see the ocean in different colors that show the different temperatures found on the ocean's surface. • Water near the equator is warm (light blues). • Water near the poles are cold (dark purples).
Includes the ground and the inside of the Earth Lithosphere
Lithosphere • The surface of the lithosphere is uneven. There are high mountains ranges like the Rockies and Andes (in reds), huge plains like those in Texas and Brazil (in greens), and the deep valleys of the ocean floor (in blues). • But the surface of Earth is only the very top of the lithosphere. • If you look at the cut-away globe, you can see the rest of the lithosphere with its many layers like an onion: the very thin crust on top, the thick mantle underneath, and the huge core of liquid iron at the center.
Spheres in Everyday Life • Every time you breathe or fly a kite, you are contacting the ATMOSPHERE. • When you play with your pets, you are contacting the BIOSPHERE. • When you drink water or go swimming you are contacting the HYDROSPHERE. • When you climb a mountain, or dig a hole, you are contacting the LITHOSPHERE.
The Water Cycle • Water never stops moving. • Snow and rain fall to the Earth from clouds. The rain and melted snow run downhill into rivers and lakes. • Eventually the water flows into the ocean. • During evaporation, the water turns from liquid into gas, and moves from oceans and lakes into the ATMOSPHERE where it forms clouds. • Then the cycle begins all over again.
The Water Cycle • How do these changes happen? Adding or subtracting heat makes the cycle work. If heat is added to ice, it melts. If heat is added to water, it evaporates. • Evaporation turns liquid water into a gas called water vapor. • If heat is taken away from water vapor, it condenses. Condensation turns water vapor into a liquid. If heat is taken away from liquid water, it freezes to become ice.
The Rock Cycle cools quickly.
The Rock Cycle • Magma cools and crystallizes to form igneous rock. • Igneous rock undergoes weathering (or breakdown) to form sediment. The sediment is transported and deposited somewhere (such as at the beach or in a delta, or in the deep sea). • The deposited sediment undergoes lithification (the processes that turn it into a rock). These include cementation and compaction.
The Rock Cycle • As the sedimentary rock is buried under more and more sediment, heat and pressure cause metamorphism to occur. This transforms the sedimentary rock into a metamorphic rock. • As the metamorphic rock is buried more deeply (or as it is squeezed by plate tectonic pressures), temperatures and pressures continue to rise. If the temperature becomes hot enough, the metamorphic rock undergoes melting. The molten rock is called magma. • This completes the cycle, then the cycle begins all over again.