Exploring Earth's Layers: Crust, Mantle, & Core

1. Inside the EarthChapter 7 section 1 Standard: S6E5.a Compare and contrast the Earth’s crust, mantle, and core including temperature, density, and composition.

2. Objectives: • Identify the layers of the Earth by their chemical composition. • Identify the layer of the Earth by their physical properties.

3. The composition of the Earth. Earth is divided into 3 layers - the crust, the mantle, and the core – based on the compounds that make up each layer. • Less dense compounds make up the crust and mantle • Densest or heavier compounds make up the core.

4. The Crust • Solid, outermost layer • 5 to 100 km thick • Temp. ranges 0°C to 1,000°C • Thinnest layer • Less than 1% of Earth’s mass • 2 types of crust – continental and oceanic • Both mostly contain elements of oxygen, silicon, and aluminum • denser oceanic crust also contains twice as much iron, calcium, magnesium

6. The Mantle • solid layer between the crust and the core • Contains most of the Earth’s mass, 67% • 2,900 km thick • Temp. ranges 1000°C to 3,700°C • Clues about the mantel comes from rocks that have been pushed to the surface, and the ocean floor (underwater volcanoes) • More magnesium and less aluminum and silicon than the crust, denser than the crust

7. The Core • Layer of the Earth that extends from below the mantle to the center of the Earth. • Outer core – liquid, inner core - solid • 33% of Earth’s mass • Radius of 3,420 km • Temp. ranges from 3,700°C to 7,000°C (sun’s surface temp – 5500°C • Composed mainly of iron and contains smaller amounts of nickel but almost no oxygen, silicon, aluminum, or magnesium.

8. Earth’s Layers