Why does Earth have magnetic poles?
Show answer & explanation
Answer: Molten iron core circulation
Molten iron core circulation ✓ — Correct! Earth's outer core is molten iron and nickel. As Earth rotates, convection currents flow through this liquid metal, generating electric currents. These currents create Earth's magnetic field (geodynamo effect). The magnetic poles don't align exactly with geographic poles and even flip every 200,000-300,000 years!
Frozen magnetic rocks — Wrong. Rocks can preserve magnetic signatures but don't generate the field. Earth's magnetism comes from circulating liquid metal in the core.
Solar wind creates field — Wrong. Solar wind interacts with Earth's magnetic field (creating auroras), but the field itself is generated internally by core dynamics.
Go deeper: Magnetic pole reversal
🚀 Play today's quiz — new questions dailyMore Earth Science questions
- In folded Appalachians, why can one rock layer become a ridge while its neighbor becomes a valley?
- Loose material moves downhill from a fresh fault scarp, rounding it. What sets the smoothing speed?
- Why can a long active fault affect more river basins than a short one?
- Why does erosion happen faster near active faults than in areas with heavy rain?
- Why can quartz sand with beryllium-10 reveal how fast a whole river basin erodes?
- Earthquake shaking lasts seconds. How can it leave rock easier for later rivers to erode?