Magnetic Fields
- Moving charges creates a magnetic field.
- The magnetic north pole of the Earth is moving (and we donât know why).
- Magnetic poles flip every once in a while.
- We can tell by looking at fault lines and seeing which way metal slivers in rocks are pointing and how old these rocks are (further from fault line = older; at fault line = newly created rock).
- Planets in The Big Chill phase (not geologically active anymore) have less of a magnetic field.
Aurora
- Aurora are charged particles from the sun interacting with our magnetic field.
- The lines in the image = the lines of our magnetic field
Things hitting Earth
- Material is constantly hitting Earth (~30,000 tons/year)
- Asteroids hit Earth and have amino acids and organic materials. These materials form in space.
Stratigraphy
Stratigraphy: the idea that lower rocks are older.
Supercontinent
All continents used to be connected.
Evidence
- Rocks separated by big distances are exactly the same.
- Fossils of animals that couldnât have swam so far are found on multiple continents.
- Coal found in Antarctica.
- Coal comes from forests and dead animals (carbon-rich).
- Continental shelf fits together ~perfectly.
How?
Convection in the Earth makes tectonic plates âsurfâ and moved continents apart.