1. Chapter 7
Plate Tectonics

2. Chap 7, Sec 1 (Inside the Earth)
Objectives:
Identify the layers of the Earth by their chemical (elements) composition.
Identify the layers of the Earth by their physical properties.
Describe a tectonic plate.

3. Tech Terms:
crust –
layer of rock
forms Earth’s outer skin
contains rocks, mountains, soil, and water
can range in thickness from km thick
the thinnest layer of the Earth.

4. separated from the crust by the Mohorovicic discontinuity
mantle –
separated from the crust by the Mohorovicic discontinuity
composed of silicon, oxygen, magnesium, iron, and calcium
acts as an amorphous solid (solid and liquid tendencies).
It’s the thickest!

6. lithosphere - the crust + the rigid upper mantle.
asthenosphere – located about 100 km to 250 km deep underground that exhibits plastic properties.

7. The Earth’s core contains two parts that make up about 1/3 of Earth’s mass, both which are made of iron and nickel.
outer core –
layer of molten, liquid, metal (despite the amount of pressure it is under)
2,260 km thick.

8. inner core –
dense ball of solid metal
1,200 km thick
temperature which is slightly hotter than the surface of the sun (7,200 °C)
It’s the hottest AND densest!