What Is Pangaea and Plate Tectonics?

What Is Pangaea and Plate Tectonics?

The Earth we see today, didn’t appear to look like this over 240 million years ago, as it didn’t have seven continents. But instead, one giant supercontinent called Pangaea, meaning all lands, which was surrounded by a single ocean called Panthalassa. All the countries lived harmoniously with each other until great break-up began to happen, which is called Continental drift as the continents slowly drifted to their current position on the Earth’s surface.

This theory was proposed by a scientist named Alfred Wegener in the year 1912 as he explained the similarities between the continents. He showed us how the South American and African contains fossils of animals like Mesosaurus in areas that match up across the ocean. He further explained that it is physically impossible for these reptiles to swim across the Atlantic Ocean. Thus we can say that these animals lived within the rivers and lakes of a single giant habitat that later broke apart.

He also showed how the ancient rocks on the Brazilian coast also matched those found in West Africa. And also he explained the presence of similar plants in different continents. But the scientific community was not entirely convinced by Wegner’s evidence due to the lack of a mechanism for how it works.

So later, the theory of continental drift was replaced by the science of plate tectonics. But what are these plate tectonics, and what causes the continents to drift apart? We need to look below our feet deep inside the Earth’s surface at the deepest layer of the planet known as core where it’s as hot as the surface of the burning sun. This center of the Earth is surrounded by mantle, which is covered by the crust, the surface on which we live.

However, the ground below you or the crust is not a single solid land and is broken into many pieces like a jigsaw puzzle, called tectonic plates. And you won’t believe but the crust is continuously moving or travelling across the Earth at the rate of about 10 cm per year in the process called plate tectonics. This motion occurs on the top two layers of the Earth, the lithosphere and the Asthenosphere. The speed and movement on which these tectonics plates move is influenced by the temperature and pressure of the Asthenosphere below. Although the scientific community is still trying to figure out the driving force behind this movement. But what we surely know is, these tectonics plates move in different ways and the point at which they meet or interact is called boundaries that have created the world what we know today.

The first type of interaction is Convergent boundary. In this process the plates move towards each other and when they collide the land is pushed upwards to form massive mountains.

The second type of interaction is called the Divergent boundary in which two plates move apart. In this process, the space between the two plates widens and becomes a massive rift such as Mid Atlantic ridge between South America and Africa.

And finally, the third interaction is called Transform boundary, in which the Earth’s plate slide past each other, in opposite directions. The grinding of the transform boundaries can create pressure that could lead to many earthquakes like what happens in San-Andreas fault.

Did you know, the Himalayan Mountains including Mount Everest were formed by the Convergent boundaries of the Indian Plate and the Eurasian Plate? These plates are still colliding with each other which is why Mount Everest grows at 1 cm per year.