BETA
Chapter 1
The magic of magnetism
Chapter 2
Music on a ribbon
Chapter 3
The spinning platters
Chapter 4
Swiping through life
Chapter 5
Earth's ancient tape recorder
YOUR GOAL
Master of How magnetic surfaces keep our secrets
Ch 5 · Earth's ancient tape recorder
007skaty Align the magnetic loops to learn how Earth's surface acts as a protective shield.
007skaty Geophysicists Fred Vine and Drummond Matthews mapped symmetrical magnetic polarity patterns along mid-ocean ridges to confirm seafloor spreading
007skaty A scientific visualization maps the magnetic surface of the cooling Mid-Atlantic Ridge
Fun Fact
Lightning-made magnets: Natural permanent magnets called lodestones are created when high-voltage lightning strikes iron-rich rocks, instantly aligning their magnetic domains.
Glossary
paleomagnetism (noun)
The study of the record of the Earth's magnetic field in rocks, sediment, or archeological materials. In 1963, researchers analyzed magnetic stripes on the ocean floor to confirm the theory of continental drift.
The study of the record of the Earth's magnetic field in rocks, sediment, or archeological materials. In 1963, researchers analyzed magnetic stripes on the ocean floor to confirm the theory of continental drift.
Quiz
What naturally magnetic mineral was used by ancient civilizations to construct the first compasses?
Quiz
What geological feature acts like a giant magnetic tape recorder as tectonic plates pull apart?
Quiz
What is the scientific study of Earth's ancient magnetic field preserved in rocks called?
Quiz
Approximately how long ago did the last major reversal of Earth's magnetic poles occur?
Quiz
What physical property of magma allows iron minerals to align with Earth's magnetic field as it cools?
Quiz
During which ancient Chinese dynasty were the first spoon-shaped lodestone compasses invented?
Quiz
How do scientists believe lodestones in the Earth's crust originally became so strongly magnetized?