The Five Major Landforms of Earth

Earth's Macro-Relief: The Big Five

1. Continents

• 7 major landmasses: Asia, Africa, North America, South America, Antarctica, Europe, Australia
• Comprise 29% of Earth's surface
• Composed of continental crust (granitic, thick, buoyant)

2. Oceans

• 5 oceans: Pacific, Atlantic, Indian, Southern (Antarctic), Arctic
• Cover 71% of surface; 97% of Earth's water
• Oceanic crust (basaltic, thin, dense)

3. Mountains

• Elevated, steep, rugged terrain
• Formed by: tectonic collision (Himalayas), volcanism (Andes, Cascades), fault-block (Sierra Nevada), erosion remnants
• Highest: Everest (8,848 m); longest range: Andes (7,000 km)

4. Plateaus

• Elevated, relatively flat-topped ("tablelands")
• Formed by: uplift (Tibetan Plateau), volcanic flooding (Deccan Traps), erosion (Colorado Plateau)
• Tibetan Plateau = "Roof of the World" (avg 4,500 m, 2.5M km²)

5. Plains

• Broad, flat/low-relief areas at low elevation
• Formed by: sediment deposition (Indo-Gangetic, Mississippi), erosion (peneplains), lava flows (Snake River Plain)
• Breadbaskets of the world: wheat, corn, rice, soy

These five categories organize Earth's solid surface at the grandest scale.