Distribution of Oceans and Continents | Class 11 Geography Notes

CONTINENTAL DRIFT

The theory of Continental Drift was first suggested based on the remarkable symmetry of the coastlines of the Atlantic Ocean. Observing how the shorelines of the Americas, Europe, and Africa appear to fit together like pieces of a jigsaw puzzle, scientists hypothesized that these continents were once joined. The earliest suggestion of this idea came from Abraham Ortelius, a Dutch map maker, in 1596. Later, Antonio Pellegrini drew maps showing the three continents together. However, it was Alfred Wegener, a German meteorologist, who formulated the comprehensive Continental Drift Theory in 1912. Wegener proposed that all continents were once part of a single supercontinent called Pangaea (meaning 'all earth'), surrounded by a mega-ocean named Panthalassa ('all water'). Around 200 million years ago, Pangaea began to split into two large landmasses: Laurasia in the north and Gondwanaland in the south. These two further fragmented to form the present continents. This theory explained the distribution of oceans and continents and laid the foundation for modern geology and plate tectonics.

📊 Diagram: See figure_1: Image showing the distribution of oceans and continents as per the theory of continental drift.

🧪 Activity: Observe the shape of the Atlantic Ocean coastlines on a world map and note the symmetry between the Americas and Africa-Europe.

🔗 Connection: Leads to the next section which discusses the evidence supporting the Continental Drift theory.