1. Layers of the Earth

2. Structure of the Earth Structure of the Earth: series of spheres held together by gravity * center of Earth is most dense; it gets less dense as you move outward from the center

3. Structure of Earth ctd * center of Earth is most dense; it gets less dense as you move outward from the center See pg. 10 of ESRTs

4. Structure of the Earth Ctd See pg. 10 of ESRTs Crust: thin, outermost solid layer of the Earth (2 kinds) See pg. 10 of ESRTs Mantle: thick, mainly solid layer (~ 2800 km thick) Core: innermost region of the Earth (2 parts) a) oceanic: 20–40 km thick; basalt; 3 g/cm 3 (MORE dense) b) continental: 40–65 km thick; granite; 2.7 g/cm 3 (LESS dense) a) outer core: LIQUID iron (~ 2200 km thick) b) inner core: solid iron & nickel (~ 1300 km thick) Outer core is LIQUID – WRITE this in your ESRTs NOW!!

5. Structure of the Earth continued Lithosphere: the crust & upper part of the mantle (~100 km thick) * * dense outer shell of Earth composed of rock Solid rock Info on the above comes from: a) seismic data (we hit the Earth with waves) b) meteorites c) drill holes d) volcanoes * * oxygen & silicon are the 2 most abundant elements Asthenosphere: lower part of the mantle (~ 500 km thick) * * NOT brittle like rock; it’s squishy ductile (plastic putty)

6. Surface Layer (liquid) Hydrosphere: consists of the Earth’s water (H 2 O) (oceans, lakes, rivers, etc) water * * oceans cover 70% of Earth’s surface (on average ~ 3.8 km deep / thick Pg 1 ESRTS Hydrosphere: consists of the Earth’s water (H 2 O)

7. Exterior Layer (gases) Atmosphere: shell of gases surrounding Earth Extends many km up to the edge of space It’s layered into temperature zones Each layer is separated from the next by a “pause” (interface) Pg 14 ESRTs

8. Exterior Layer (gases) The Atmosphere’s composition is mainly: 78% nitrogen 21% oxygen 1% other (argon, carbon dioxide, helium, water vapor) Pg 1 ESRTS

9. DRAW the layers of the atmosphere troposphere stratosphere mesosphere thermosphere troposphere stratosphere mesosphere thermosphere mesopause stratopause tropopause least dense most dense density decreases Earth fades out to space Pg. 14 ESRTs only layer w/ water vapor

10. Layers of the Earth - RECAP ** see pg 10 of ESRTs – Inferred Properties of Earth’s Interior… ** see pg 1 of ESRTs – Average Chemical Composition of Earth’s Crust, Hydrosphere and Troposphere ** see pg 14 of ESRTs – Selected Properties of Earth’s Atmosphere