The Earth we know today - with its vast oceans and seven distinct continents - looked vastly different millions of years ago. At one point, all the landmasses were connected, forming a single giant continent known as Pangea. But when did the supercontinent Pangea start to break up, and why?
The answer lies in the dynamic forces beneath the Earth's surface, and understanding this breakup helps us better appreciate the planet's ever-changing landscape.
Pangea existed during the late Paleozoic and early Mesozoic eras, about 300 million years ago. It remained intact for millions of years before the tectonic forces that once pulled it together began to tear it apart.
The Formation and Significance of Pangea
Pangea was not the first supercontinent in Earth's history, but it is undoubtedly the most famous. Its name, derived from Greek, means "all Earth," which is fitting considering it combined nearly all the planet’s landmasses. Its formation was part of a long cycle of continents coming together and breaking apart, a process driven by the movement of tectonic plates.
These plates constantly shift and interact, causing earthquakes, volcanic activity, and the movement of entire continents.
Lastly / Pexels / At its peak, Pangea covered nearly one-third of the Earth's surface. Its existence significantly affected global climate patterns, ocean circulation, and the evolution of life.
The creatures that roamed Pangea, like early reptiles and amphibians, had the freedom to spread across a vast, uninterrupted landmass. However, this unity of land was temporary. The very forces that formed Pangea would eventually rip it apart.
When Did the Supercontinent Pangea Start to Break Up?
So, when did the supercontinent Pangea start to break up? The breakup began approximately 175 million years ago during the early Jurassic period. The process was not immediate. It occurred slowly over millions of years. The Earth’s internal heat caused the mantle to convulse and push upwards, creating fractures in the crust. These fractures eventually turned into rifts, eventually dividing Pangea into separate landmasses.
The first major division occurred between what is now North America and Africa. Over time, the Atlantic Ocean started to form as the landmasses drifted apart. This marked the early stages of the eventual formation of the continents we recognize today. The breakup of Pangea was not a singular event, though. Instead, it was a series of gradual separations that continued for tens of millions of years.
The Role of Plate Tectonics in Pangea's Breakup
Understanding when the supercontinent Pangea started to break up also involves comprehending the forces behind this colossal shift. The Earth's lithosphere, made up of the crust and upper mantle, is broken into tectonic plates.
These plates are in constant motion due to convection currents in the underlying mantle. Hot material rises from deep within the Earth, while cooler material sinks, creating a cycle that moves the plates.
Julia / Unsplash / During Pangea's time, the tectonic plates moved slowly but steadily, causing stress to build up at weak points in the Earth's crust.
Over time, these stresses became too great, leading to rifts and the separation of landmasses. It is incredible to think that the gradual movement of these plates, sometimes only a few centimeters a year, could reshape the entire world.
The Gradual Evolution of the Continents
After Pangea split into Laurasia and Gondwana, these two large landmasses continued to fragment. Laurasia drifted northward, eventually forming North America, Europe, and Asia. Meanwhile, Gondwana moved southward, breaking up into South America, Africa, Antarctica, and Australia.
As the continents shifted, oceans like the Atlantic and Indian Oceans formed, and the global landscape began to resemble what we see today. These shifts drastically altered the Earth’s climate and ecosystems. Species that had once lived together on the same landmass were now isolated, leading to the evolution of new species adapted to their unique environments.
