Earth: Systems, Structures and Processes Unit 4 Earth: Systems, Structures and Processes Goal: Understand the structure of the earth and how interactions of constructive and destructive forces have resulted in changes in the surface of the Earth over time and the effects of the lithosphere on humans.

Earth: Systems, Structures and Processes Unit 4 Earth: Systems, Structures and Processes Summarize the structure of the Earth, including the layers, the mantle, and core based on the relative position, composition, and density. Explain how crustal plates and ocean basins are formed, move, and interact using earthquakes, heat flow, and volcanoes to reflect forces within the earth. Explain how the formation of soil is related to the parent rock type and the environment in which it develops. Conclude that the good health of humans requires: monitoring the lithosphere, maintaining soil quality, and stewardship.

How do we know about Earth’s interior? Geologists have used two main types of evidence to learn about Earth’s interior: Direct evidence from rocks. rocks give clues about Earth’s structure. 2. Indirect evidence from seismic waves (produced by earthquakes) speed and path tell about the Earth’s structure. https://app.discoveryeducation.com/learn/videos/af8aeaca-f326-442b-a837-546e77bd2358?hasLocalHost=true

What are the main layers of the earth? The 3 main layers of the Earth are: Crust Mantle Core

Crust: solid rock that includes: - continental crust (dry land) - oceanic crust (ocean floor) - lithosphere thinnest layer 5 – 70 km thick continental crust: thicker than oceanic crust made of igneous rock (granite) oceanic crust: ocean floor is igneous rock (basalt) lithosphere: rigid layer formed from the uppermost part of the mantle and the crust

Mantle: * 2 layers: - asthenosphere - lower mantle * very hot solid rock * thickest layer * 2,900 km thick asthenosphere: soft rock, like hot road tar (400 km) lower mantle: hard rock

Core: made of iron and nickel 2 layers: outer core inner core - liquid metal - flows in currents - giant magnetic fields created inner core - hottest layer - solid metal - under extreme pressure

Journey to the Center of the Earth Temperature: Increases going deeper into Earth; high temperatures are result of heat left over from the formation of the planet. Pressure: Increases going deeper into Earth; results from a force pressing on an area.

Exploring the Layers of the Earth 5 min