Beginning of Notes
Processes at or beneath Earth’s surface
: It’s immensity (Billions of years) is very hard to grasp.
second- hours: earthquake, volcano
Hundreds of years: erosion
Millions of years: evaluation
Tens of million-billion years: mountain range forming
Universe is about 15 Billion years old
Solar system 4.5 Billion years old (4,500,000,000). Sun with 9 planets
a.) Terrestrial- small, rocky, dense-mercury. Venus, Earth, Mars.
b.) Jovian- Large, Gassy, Light. Jupiter, Saturn, Uranus, Neptune.
Solar system formed from relatively cold material
Formed from Nebula of gas and dust that undergoes accretion
Earth warms up very rapidly
Collision, aluminum heating,
– Inner layer heating,
Decay of radioactive materials
Inside earth, continues today.
Early Earth became(partially) molten. Caused in part by collision with Mars size body; created moon, then cooled
Rocks are very poor heat conductors
Once crust forms, inside still remains very hot- even today: 5,000
Earth may be uniform in composition (inside and outside) at first, but because of heating became differentiated-
Once temperature is high enough, iron melts and falls to the center, causes release of energy and more heating – called the Iron
This huge heating event causes “boiling off” of volatiles from inside. Water, other gases “belched” to the outside- “The Big
Burp” forms early ocean and atmosphere
both are different from today.
Look at layering in 2 different ways
distances measured from the surfaces of earth- radius= 6400 KM
Based on Composition
Crust- solid rock ~40 km depth
Mantle- different type of solid rock~ 40-2900 km depth
Outer core- Liquid iron 2900-5100 km depth
Inner Core- Solid Iron 5100-6400 km depth