The Earth’s Interior and how it works.

The 3 Main Layers Core Mantle Lithosphere Inner Core Outer Core Mesosphere Asthenosphere Lithosphere Uppermost mantle Crust

The Core Metallic - Fe & Ni. Inner core (Solid) Outer core (Molten) The internal source of heat energy for the Earth.

The Mantle The broad middle section of the Earth. (Rocky) Asthenosphere contains the convection currents that drive the “plates”. (Plastic) Mesosphere

What are Convection Currents? Convection occurs in the asthenosphere due to the heat from the core. Remember hot = less dense therefore rises and cooler = more dense therefore sinks.

The Lithosphere The “Plates” (Rocky) Consists of the crust and the uppermost mantle. (Solid) Each plate moves as one section of the Earth on top of the asthenosphere. Uppermost Mantle

Types of Crust Continental Crust Oceanic Crust Thickest at the highest mountains Thinnest in the deepest ocean. Made up of sedimentary and Made up of igneous rock. metamorphic rock.

The “Plates”

How the Layers of the Earth Work Together Heat energy from the CORE is transferred into mechanical energy in the ASTHENOSPHERE Which drives the plates – the LITHOSPHERE. PLATE TECTONICS

PLATE TECTONICS Plate movement which gives us volcanoes, earthquakes, mountains, rift zones, or any combination of these.

Plate Tectonics & Rocks Pressures high enough to change the crystalline structure of rock result in metamorphic processes. Metamorphic rock. Temperatures high enough to melt rock result in magma and igneous processes. Igneous rock.

The External Processes and how they work. Heat energy from the sun is converted to mechanical energy in the atmosphere. The result is the hydrologic cycle. Script: “As the heat from the core is the driver for the internal heat engine, the heat from the sun is the source for the external heat engine. The sun’s energy is greatest at the equator of the Earth. At this latitude, the majority of the planet is covered with water. The great amount of heat energy causes evaporation which then sets up density/convection currents in the atmosphere. As air masses move upward other air comes in to take its place and winds are established. It’s highly complicated as there are many variables, but also as the air masses move, condensation occurs and then precipitation occurs which starts the whole water cycle and keeps it going.”

The External Processes The water cycle and gravity provide the mechanisms for the tearing down of the earth. The resulting processes are weathering and erosion. The result is sediment and sedimentary rock.

The Great Earth/Rock Cycle Sedimentary Rock Deposition & Lithification Extreme Temperature and Pressure Sediment Weathering & Erosion Metamorphic Rock Script: “ This is the newly named Earth/Rock cycle. If you start at the bottom with magma and then follow the cycle up and to the left; cooling of the magma results in igneous rock. Weathering and erosion of igneous rock produces sediment. The sediment is deposited and then the water is squeezed out and the rock is cemented and hardened – lithification. This results in sedimentary rock. When sedimentary rock is buried further and subjected to pressure and temperature metamorphic rock will result. When the metamorphic rock is further subjected to rising temperatures, it melts to become magma and the whole cycle begins again. It is important to note that the Earth/Rock cycle does not have to follow this one direction. Sedimentary rock can weather and erode to become sediment. Metamorphic rock can weather and erode and become sediment as igneous rock can remain underground and become metamorphic rock. The importance of any type of rock is the story it tells. Igneous and metamorphic rock tell about internal processes of the earth while sediment and sedimentary rocks tell about the external processes of the earth.” Igneous Rock Extreme Temperatures/ Melting Eruption/Cooling MAGMA