Geographers typically encompass all of the islands connected to a continent while identifying it. The Earth’s crust and the upper mantle combine to create a solid shell divided into enormous chunks known as tectonic plates. Tectonic plates are still slowly drifting across the Earth’s Surface as they have been for hundreds of millions of years. The names were initially mainly used for areas close to the coast, and the hinterlands were added later. Eventually, the division into three parts commenced taking center stage. This would later develop into the 7- continent model we have today. But why don’t the present shapes of continents fit perfectly and what will happen if continents joined back together? Let’s find out.
1. When did the Continents Split?
One of the earliest hypotheses put up by geologists for how continents might split and continents joined back together through time is called continental drift. Wegener wrote a paper outlining his notion that the continents split across the Earth, occasionally crashing through oceans and into one another, in the early 20th century. He referred to this motion as continental drift.
This led to the finding that the rock layers on the eastern shores of America and the west coast of Africa fit just as plainly as pieces of a jigsaw puzzle. Africa and South America weren’t the only exceptions to such continents with comparable geology. Roughly 240 million years ago, Pangaea existed.
Approximately 200 million years ago, this supercontinent began to fragment. Pangaea split into fragments throughout millions of years, and each piece migrated away from the other. These components gradually came together to form the continent that is known today. But why don’t the present shapes of continents fit perfectly? Let’s find it out in the upcoming segments. (See Where are Modern Continental Rifts?)
2. Why is it called Pangea?
According to geologists, the friction of the plates, or plate tectonics, was a factor in the present shapes of the continent’s formation. Early in geological timescales, a supercontinent called Pangea—also written Pangaea—included practically all of the Planet’s landmasses.
Going back to the Early Jurassic Epoch (201 million to 174 million years ago), the supercontinent started to disintegrate, branching down into the current continents and the Atlantic and Indian seas. Alfred Wegener, a German meteorologist, first suggested Pangea’s existence in 1912 as part of his theory of continental drift. Its name originates from the Greek word Pangaea, which means the entire Earth.
3. Does the World fit like a Puzzle?
The fragments of Earth’s shattered crust are now of different sizes. The largest plates—Africa and the Pacific—are antipodal or located on opposite sides of the Planet. However, some 100 million years ago, the world was tiled by the tectonic plates like an authentic jigsaw puzzle.
According to the plate tectonics hypothesis, the Planet’s crust is fragmented into plates that move across the subsurface mantle at a rate of inches (centimeters) per year.
According to the researchers, top-down tectonics, with massive, sinking plates in charge, predominate when large plates are dominant. Such was when Pangaea, a supercontinent, blanketed the Earth roughly 200 million years ago. However, when the components or shapes of the continents fit together perfectly, bottom-driven mantle forces take over. Convection flux in the Planet’s mantle draws and pushes the plates around, causing the plates to move. This is a reason why don’t the present shapes of continents fit perfectly. (See Where is the Ending Point of Earth?)
4. How are the Seven Continents divided?
The locations of the world’s continents were tremendously different around 300 million years ago. In reality, there was only one continent, not even seven. Pangea was a single, enormous supercontinent in the late Paleozoic and early Mesozoic periods. Pangea was split into several landmasses due to tectonic movements that lead to fissures that alter the positions of the continents that reside on the tectonic plates.
Gondwana, which included Africa, South America, India, Australia, and Antarctica, i.e., all the continents split apart from Laurasia, which included Europe, North America, and Asia, some 200 million years ago. Gondwana split up once more 50 million years down the line, dividing the continents within the confines of it. Then, some 60 million years ago, Laurasia also broke up. The many continents shifted throughout time. Eventually, the final continents joined back together and the shapes of the continents fit and established themselves as the seven continents we see presently.
5. Do the Continents Fit Perfectly together?
In originality, Gondwana can be reconstructed by aligning the southern landmasses. But why don’t the present shapes of continents fit perfectly? The vividly prominent illustration, given by academics for centuries, is how the shapes of the continents fit flawlessly today with respect to Africa and South America. The edges of the continents align almost exactly. All the shapes of the continents fit together very well when considering the full continental form rather than the visible, dry land portions. Strong evidence suggests that all our present-day continents were connected, but eventually, the continents split. Check out Which Hemisphere has Maximum Number of Continents?
6. How do the Shapes of the Continents fit?
By now you must have some ideas why don’t the present shapes of continents fit perfectly. Wegener’s Principle of Continental Drift is the foundation for the Theory of Plate Tectonics. The lithosphere is made up of tectonic plates. The crust and upper mantle make up the lithosphere. These fragments drift on the asthenosphere, a layer of partially liquid rock. Because the lithosphere is more substantial and robust than the rock beneath, tectonic plates can move inside it. The larger major plates are
- African Plate
- Antarctic Plate
- Eurasian Plate
- Australian Plate
- North American Plate
- Pacific Plate
- South American Plate
Eight additional smaller secondary plates are present. Other even more tiny microplates are also known. It was discovered that South America elegantly tucks into the region of Africa just about as fast as the continents were surveyed. If you take into account the small marine shelf that surrounds their beaches, this fit is considerably better.
- Together with Ellesmere and Baffin islands, Greenland looks to belong.
- The west coasts of Madagascar, India, and Africa appear appropriate.
- The Mid-Atlantic Ridge runs parallel to Africa and Europe on one side and North and South America on the other.
- Alfred Wegner discovered comparable findings on the borders of other continents after studying the fossils of extinct plants and animals, physical features on the continent’s borders, and mineral deposits.
7. Why don’t the Present Shapes of Continents Fit perfectly?
Due to several important geological factors, the current forms of the continents do not fully match a supercontinent.
- First, as the continents stretched apart, the new rock began to form at the gap where magma had previously surged to the Surface.
- Second, even after the continents broke away from Pangaea, the supercontinent, they continued to clash throughout the following million years. Due to the formation of mountain ranges and convergent boundaries, the shapes of the continents and their borders were altered.
- Finally, while deposition from ocean circulation and river valleys contributed landmass to some beaches, natural processes degraded parts of the continental coastlines. Now you know why don’t the present shapes of continents fit perfectly.
8. Which Two Continents can Fit like a Puzzle?
Alfred Wegener found out that the center Atlantic Ocean, which lies between northern Africa and North America, and the southwest Indian Ocean, which lies between Africa and Antarctica, were the initial waters to develop from the splitting 180 million years ago. Africa and South America split apart approximately 140 million years ago, causing the South Atlantic Ocean to emerge.
The Americas, North Asia, and Europe seemed to be previously neighbors as members of the Laurasia. Africa, on the contrary, contrary Asia in South Antarctica. Due to their shared origins in Gondwanaland, Australia, and South America were neighbors. If the margin of the continental shelf is used as a guide to establishing the boundaries of North America, Europe, and South America, then for a certainty, the present shapes of these continents also fit together quite well. Learn What are Types of Map Symbols?
9. Why the Continents could not Possibly move the Way Wegener is describing?
Wegener’s theory was synonymously rejected since he did not explain how the continents might drift apart. He believed that the spin of the Earth was adequate to move continents, but geologists know that rocks are too strong for this to be a plausible explanation. A Scottish geologist named Arthur Holmes proposed a theory explaining why continents split in 1928. He thought that a heat trap in the Earth created convection currents.
There were certain pressure points where the trapped fluids under the crust of the Earth heated up, rose, spread laterally, then cooled and fell back. Although it was not widely accepted, this theory was reintroduced in the 1940s and 1950s when scientists learned more about the seafloor’s magnetic properties. Multiple possibilities exist where the plates’ edges touch. This is why don’t the present shapes of continents fit perfectly. (Also read What is the Best Piece of Evidence for Plate Tectonics?)
10. What if all Continents joined back together?
There are theories that a supercontinent could emerge around the north pole, engulfing all of the continents save Antarctica, though scientists aren’t totally positive about this. A supercontinent made up of all the continents joined back together at the equator might be an alternative. But what about the reasons why don’t the present shapes of continents fit perfectly?
There is still a lot of space for creativity and imagination regarding what it might be like to live on these supercontinents. With all the continents save Antarctica around the north pole in the eventuality of Amasia, the supercontinent would experience significantly cooler temperatures and ice cover all year. Because there would be more water in the polar ice caps, the ocean level might also drop.
On the other hand, the result would be contrary in the case of the Aurica supercontinent. Rising temperatures would result from larger landmass near the equator absorbing greater heat, partly due to the removal of the arctic ice. The globe could become 3 °C hotter due to Aurica. The climate among these two scenarios differs dramatically, with mean surface temperature changes of several degrees.
11. Will Earth become a Super Continent again?
Since you know why don’t the present shapes of continents fit perfectly, you must note that in the 4.5 billion years of Earth’s geologic history, Pangaea wasn’t the first supercontinent to arise. It won’t be the last, as its legacy as a supercontinent is feared to continue. Tectonic plate motions can be monitored by researchers employing GPS equipment. However, paleontologists must look to inherent magnets in the Earth’s crust to put together just what plates were doing millions of years ago.
Scientists may use that alignment to determine where, in regards to latitude, the magnets were situated in the past as the after that cooled rock travels via plate tectonics. Ross Mitchell, a geologist at Curtin University in Perth, estimates that a novel supercontinent creates roughly every 600 million years, although that cycle may be accelerating. This implies that the formation of Amasia, also known as Pangaea Proxima, would occur earlier than anticipated. There is no reason to believe that another supercontinent won’t arise in the future, given that it has previously occurred three times in the past.
12. How will the Earth look in 100 Million Years?
One prediction is that Novopangea, a brand-new supercontinent, will emerge. The Atlantic will enlarge, and the Pacific will contract due to this. Africa will meld into a unified Eurasia that includes the Americas and Antarctica. One landmass of originally distinct continents will constitute the result. Another possibility was a Pangea Ultima that would see a central sea form.
The Americas will eventually encompass Africa as Antarctica divides in half. Australia would be situated south-facing the new united India and China, whereas Eurasia will have India and China to its immediate south. Another prediction points to a phenomenon called Amasia. While discussing why don’t the present shapes of continents fit perfectly, we may observe a commotion of continents towards the location of the Arctic when tectonic plates move further north. Antarctica will remain steadfast in its position. (Also read What are Movements of the Earth?)