Chapter 03 of 5
Frozen in Stone
Unlocking Earth's history through paleomagnetism and ancient lava.
- Natural Archives
The Memory of Rock
Earth’s crust acts as a global hard drive. It permanently records the magnetic field's orientation at the moment of its birth.
- Mechanism
Magnetic Compass Stones
Rocks containing magnetite act as tiny compass needles. As magma cools, these minerals align with the North Pole and lock in place.
- The Threshold
The Curie Point
When minerals cool below roughly 580°C, their magnetic alignment becomes permanent. This frozen signature is known as remanent magnetism.
17 more cards in this chapter
Could you answer this?
What is the specific temperature threshold at which minerals permanently lock in their magnetic orientation?
🧲 Geomagnetic Flips
- 01The Glitch in the ShieldWitness the modern wandering of the North Pole and the South Atlantic Anomaly.
- 02The Geodynamo EngineHow molten iron and the Coriolis effect generate a planetary magnet.
- 03Frozen in StoneUnlocking Earth's history through paleomagnetism and ancient lava.
- 04The Chaotic ReversalWhat happens to the magnetosphere during a full magnetic flip.
- 05The Fate of a Dead CoreWhy the churning heart is the only thing keeping us from becoming Mars.