Earth's hard surface is cracked into giant tectonic plates. Slow convection currents in the hot mantle drag them around the planet — building mountains, oceans, and quakes.
🌋What Moves the Plates?
Hot rock rises, cools, and sinks again — these looping convection currents slowly drag the plates above them.
The plates are the cracked, rocky crust riding on top of the soft, hot mantle.
↔️Three Kinds of Plate Boundaries
↔️DIVERGENT
MotionPlates pull APART
ResultNew crust forms; ground splits open
🌊 Mid-ocean ridge
💥CONVERGENT
MotionPlates COLLIDE
ResultMountains rise; one plate may subduct
⛰️ Mountains & trenches
↕️TRANSFORM
MotionPlates SLIDE past
ResultFriction builds, then snaps → quakes
🌎 Earthquake faults
🧩Pangaea & Continental Drift
All the land was once one supercontinent. The plates keep moving today — about as fast as your fingernails grow.
🧩 A puzzle-piece planet!
The coastlines of South America and Africa fit together like puzzle pieces.
Matching fossils on both continents are a clue they were once joined.
🔑Key Terms
🧩Tectonic PlateA giant slab of Earth's crust that slowly slides over the soft mantle below.
🌏Continental DriftThe idea that continents slowly move across Earth's surface over time.
🗺️PangaeaThe single supercontinent that broke apart about 200 million years ago.
♨️Convection CurrentHot mantle rock circling as it heats, rises, cools, and sinks — moving the plates.
🌊Sea-floor SpreadingMolten rock rises at a mid-ocean ridge and adds brand-new ocean floor.
⬇️SubductionOld ocean floor sinks into a deep trench and melts back into the mantle.
⭐Remember: Earth's plates are still moving right now! Heat-driven convection currents in the mantle keep dragging the continents apart — super slowly, but never stopping.