1. EARTH’S LAYERED STRUCTURE
The Earth is like an onion…it has many layers.

2. Earth’s Layers = Zones Earth’s interior consists of 3 major zones:
Crust
Mantle
Core
Inner core
Crust
Mantle
Core
Inner Core

3. Zones defined by COMPOSITION
Crust
Thin, rocky
Oceanic/ Continental
Basalt and Gabbro
Average composition is called granodiorite
Density 3.0 gm/cm3
Crust

4. Zones defined by COMPOSITION
Mantle
82% volume of Earth
Solid, rocky
Periodotite
Density 3.4 gm/cm3
Mantle

5. Zones defined by COMPOSITION
Core
Iron-nickle alloy
Density = 13 g/cm3
Core
Inner Core

6. Zones Defined by PHYSICAL PROPERTIES
Lithosphere
Cool, rigid
Asthenosphere
Soft, weak
Lower Mantle
More rigid, gradual flow
Outer Core
Liquid
Magnetic Field
Inner Core
Compressed solid
Lithosphere
Asthenosphere
Lower Mantle
Outer Core
Inner Core

7. MOHO! Mohovorovicic discontinuity
Discovered by studying seismic waves
Separates crust from mantle
Lead to discovery of bending of waves at core