1. EARTH’S STRUCTURE

5. Crust – outermost layer
Mantle – solid near the crust, but flows like putty near the core
Core – has an inner and outer core

6. THE CRUST
The outermost layer, the crust, is made up of lightweight rocks.
miles deep
Makes up about 1% of Earth’s mass
Main elements in this layer are oxygen, silicon, and aluminum.

7. The are two kinds of crust: continental crust and oceanic crust.
Continental crust is lighter, older, and thicker that make up the continents
Oceanic crust is the rock that forms the ocean floor.

8. The crust and upper part of the mantle form the LITHOSPHERE.
The Lithosphere is divided into TECTONIC PLATES - large sections of Earth’s crust they move slowly by floating on top of dense, partly melted rock.

9. Tectonic plates drift across Earth’s surface at rates ranging from less than 2 cm to more than 15 cm per year.

10. THE MANTLE The mantle is the layer below the crust. 1800 miles thick
Makes up 67% of Earth’s mass
Main elements are iron, magnesium, aluminum, and silicon
The mantle is denser than the crust

11. The uppermost part of mantle is solid
The middle part is more like a thick liquid
The lowest section is solid, even though its temperatures is even higher than that of the middle layers.
Pressure is so great, the solid cannot melt

12. THE CORE The Earth’s innermost layer is the core. 2200 miles thick
Makes up about 32% of Earth’s mass
The core is MOSTLY iron, with a little bit of nickel.

13. Earth’s core consists of two parts: inner and outer cores
The outer core is liquid, but high pressure keeps the inner core solid.
The temp. at the very center of Earth is 6,000°C or 10,832°F
The pressure is four million times greater than the pressure at Earth’s surface