The Continents Are Shifting. When Will They Collide?

Alfred Wegener, a meteorologist, discovered startling parallels between the coasts of South America and Africa at the beginning of the 20th century. These observations prompted him to put up a contentious new hypothesis: perhaps these and numerous more continents were once joined to form a single, enormous landmass.

Wegener's Theory of Continental Drift immediately refuted the widely held belief. It took his supporters about 50 years to persuade the rest of the scientific community that Earth's continents had been stable for millennia. But as of today, we know something even more fascinating: Pangea wasn't the first supercontinent; there have been many before it, and there will be more.

Our current understanding of plate tectonics was built on the foundation of continental drift. It claims that the mantle, a layer of partially molten rock, lies above the massive, angular plates that make up Earth's crust. The only movement of these plates is between 2.5 and 10 cm every year. However, such minute movements shape the planet's surface.

We must thus forecast where these plates are going in order to identify when a new supercontinent will form. examining their prior movements is one strategy in this case. By monitoring variations in the Earth's magnetic field, geologists can determine where continents have been over time.

Magnetic minerals in molten rock get "frozen" at a precise rate as it cools. Therefore, we can determine the latitude at which a specific rock was positioned at the time of cooling by estimating the direction and intensity of the rock's magnetic field.

However, this strategy has significant drawbacks. For starters, the magnetic field of a rock cannot tell us the longitude of the plate, and the latitude measurement may be either north or south. Even worse, when the rock is reheated, as occurs during continental collisions or volcanic activity, this magnetic data is lost.

Geologists must therefore use alternative techniques to reassemble the positions of the continents. By dating local fossils and comparing them to the global fossil record, it is possible to identify previously related locations.

The same is true for the Earth's crust's cracks and other deformations, which can occasionally be linked to plate motion. These techniques have allowed researchers to piece together a rather accurate history of plate motions, and their investigation turned up a pattern that spans hundreds of millions of years.

What is now known as the Wilson Cycle foretells the continents' division and reunification. In addition, it currently suggests that the next supercontinent won't form until 50 to 250 million years. What that landmass will look like is not something we can say with much precision. A new Pangea might form as a result of the Atlantic Ocean closing.

Another possibility is that a fresh Pan-Asian ocean will arise as a result. Although its exact size and shape are still unknown, we do know these alterations will have an influence well beyond our country's borders. Colliding plates have in the past caused significant environmental disruptions.

Around 750 million years ago, the Rodinia supercontinent split off. Large land masses became susceptible to weathering. More carbon dioxide from precipitation was absorbed by the freshly exposed rock, eventually eliminating so much CO2 from the atmosphere that the planet entered a period known as Snowball Earth.

It took another 4 to 6 million years for volcanic activity to emit enough CO2 to thaw this ice. Meanwhile, it's more likely that things will get hotter when the next supercontinent coalesces. The Earth's crust may develop and widen fractures as a result of shifting plates and continental collisions, which might result in the release of significant volumes of carbon and methane into the atmosphere.

This increase in greenhouse gases would cause the world to heat up quickly, possibly resulting in a mass extinction. These fissures are so large that they would be nearly impossible to stop, and even if we did, the increased pressure would lead to more ruptures. We have at least 50 million years to find a solution, which is fortunate, and we might already be on the right track.

Recent tests in Iceland showed the ability to sequester carbon in basalt turning these vapors into stone quickly. Therefore, it's plausible that a global network of pipes could send vented gases into basalt outcrops, reducing part of our emissions now and safeguarding the future of our supercontinent.