Knowra Continents Continents Continents are Earth's largest continuous landmasses, conventionally divided into seven named regions. Their boundaries and number vary among geographic traditions.
Continental crust : Earth's relatively thick, buoyant crust, composed mainly of granitic rocks and forming the continents. Its composition and buoyancy distinguish most continental land from ocean-floor crust.
Seven-continent model : A geographic convention that counts Asia, Africa, North America, South America, Antarctica, Europe, and Australia separately. It is the familiar school model implied by the seven named regions.
Plate tectonics : The theory that Earth's lithosphere consists of moving plates whose interactions shape the surface. It explains the long-term motion and reassembly of continental landmasses.
Africa : A continent centered on the African tectonic plate and joined to Asia at the Isthmus of Suez. Its connection to Asia illustrates how convention draws boundaries across continuous land.
Oceanic crust : Earth's thin, dense crust, composed mainly of basalt and underlying ocean basins. Its contrast with continental crust helps explain why continents stand above ocean floors.
Six-continent model : A geographic convention that combines either Europe with Asia or North and South America. It demonstrates how cultural and geographic choices alter the continent count.
Continental drift : The hypothesis that continents move across Earth's surface over geological time. It anticipated the motion later explained by plate tectonics.
Antarctica : The southernmost continent, almost entirely covered by a thick ice sheet. It is a distinct continent despite having no permanent native human population.
Tectonic plate : A rigid section of Earth's lithosphere that moves over the softer asthenosphere. Continents ride on plates, whose boundaries do not match continental boundaries.
Afro-Eurasia : The continuous landmass comprising Africa, Europe, and Asia. Its uninterrupted land connection challenges treating those three regions as separate continents.
Show all 24