2. Internal Structure of the Earth

Crust

* ==Outermost==, ==thinnest== layer

Composed of @@rocks and minerals@@
* Iron (Fe), Calcium (Ca), Hydrogen (H), Aluminium (Al), Silicon (Si), Oxygen (O), Sodium (Na), Potassium (K), Titanium (Ti)
* **Continental crust** - %%Thicker%%, %%lower%% density
* **Oceanic crust** - ^^Thinner^^, ^^higher^^ density

Mantle

* ==Beneath== the crust
* Composed of mostly @@silicates, namely Silicon (Si), and Oxygen (O)@@
* Convection current is present
* %%Hot%% air %%rises%%
* ^^Cold^^ air ^^sinks^^

Outer Core

* Composed of ==Nickel and Iron==
* @@Liquid@@
* Liquid because there is not enough pressure for it to be kept solid

Inner Core

* Composed of ==Nickel and Iron==
* @@Solid@@
* Intense pressure -- prevents the iron in the core from melting

Lithosphere

* ==Solid, outer part== of the Earth
* @@Rigid and elastic layer@@ (@@upper mantle and crust@@)
* Rigid due to @@stress, temperature, and curvature of the Earth@@
* Coolest layer (literally.)
* Conducts %%heat from convection%%

Oceanic lithosphere

==Thinner and denser== oceanic crust. Primarily composed of @@basalt@@.

Continental lithosphere

==Thicker and less dense== continental crust. Primarily composed of @@granite@@.

Characteristics of a plate

* Carries both ==continental and oceanic crusts==
* Floats on @@top of the asthenosphere@@ -- slides horizontally over it, bends slightly
* Moves very %%slowly%%

Asthenosphere

* Highly ==viscous== -- ==Rocks== flow like ==liquid== (Magma)
* High @@pressure and temperature@@

7 Major Plates

African, Antarctic, Eurasian, Indo-Australian, North American, Pacific, South American

Examples of Minor Plates

Caribbean, Scotia, Arabian, India, Philippine, Juan de Fuca, Cocos, Nazca Plates