September 29th, 2022

Magnetic Fields

• Moving charges creates a magnetic field.
• The magnetic north pole of the Earth is moving (and we don’t 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 couldn’t 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 “surf” and moved continents apart.