Will Earth's next supercontinent assemble through the closure of the Pacific Ocean?

Will Earth's next supercontinent assemble through the closure of the Pacific Ocean?

North America and Asia might collide to form next supercontinent on Earth, predicts scientist

Introduction

The Earth's continents are constantly moving and changing shape over millions of years. In the past, they have joined together to form supercontinents, such as Pangaea and Rodinia, and then split apart again. But what will happen in the future? Will the continents merge into a new supercontinent? And if so, what will it look like and how will it affect life on Earth?

In this blog article, we will explore the fascinating possibility of a future supercontinent called Amasia, which might form when North America and Asia collide. We will also look at some alternative scenarios and the implications of such a drastic change in the geography of our planet.

What is a supercontinent?

A supercontinent is a large landmass that contains most or all of the Earth's continental crust. Supercontinents are formed by the movement of tectonic plates, which are large pieces of the Earth's crust that float on top of the mantle, a layer of hot and molten rock. Tectonic plates move due to convection currents in the mantle, which are driven by the heat from the Earth's core.

Tectonic plates can move towards each other (converge), away from each other (diverge), or slide past each other (transform). When plates converge, they can either subduct (one plate goes under another) or collide (both plates crumple and uplift). Subduction creates volcanic arcs and oceanic trenches, while collision creates mountain ranges and continental crust.

The formation and breakup of supercontinents are linked to the behaviour of the mantle. When heat builds up under a supercontinent, it causes the mantle to rise and thin the crust, creating rifts and volcanoes. This leads to the breakup of the supercontinent and the opening of new oceans. Conversely, when heat is lost from the mantle under an ocean, it causes the oceanic crust to sink and subduct under the continental crust, creating island arcs and closing the ocean. This leads to the collision of continents and the formation of a new supercontinent.

The cycle of supercontinent formation and breakup is estimated to take about 300 to 500 million years. The last supercontinent, Pangaea, existed about 300 to 200 million years ago. It broke up into two smaller supercontinents, Laurasia and Gondwana, which then further split into the seven continents we know today: Africa, Antarctica, Asia, Australia, Europe, North America and South America.

What is Amasia?

Amasia is one of the possible names for a future supercontinent that might form when North America and Asia collide. The name is derived from combining America and Asia. The idea was first proposed by geophysicist Paul Hoffman in 1992, based on his observation that most supercontinents form at 90 degrees from their previous locations.

According to Hoffman's theory, Amasia will form when the Pacific Ocean closes due to subduction along its margins. This will bring North America closer to Asia, eventually colliding along Alaska and Siberia. Meanwhile, South America will also move northward, colliding with North America along Central America. Africa and Europe will remain attached to Asia, forming a large Eurasian landmass. Australia will also drift northward, joining Asia along Indonesia. Antarctica will remain isolated at the South Pole.

Amasia is expected to form in about 200 to 300 million years from now. It will be centered around the North Pole, with a large Arctic Ocean surrounded by land. It will have a diverse climate and topography, with high mountains along the collision zones, vast plains in the interior, and tropical forests along the equator.

What are some alternative scenarios?

Amasia is not the only possible outcome for a future supercontinent. There are at least three other scenarios that have been proposed by different geologists:

- Pangaea Ultima: This scenario predicts that Pangaea will reassemble in about 250 million years from now. It is based on the assumption that the Atlantic Ocean will continue to widen as it has been doing for the past 200 million years. This will push Africa and Europe towards North America, closing the Mediterranean Sea and creating a new Appalachian mountain range. South America will also join North America along Mexico. Australia will collide with Antarctica and then move northward to join Asia along India. The Pacific Ocean will shrink as it subducts under Asia and North America.
- Novopangaea: This scenario predicts that a new Pangaea-like supercontinent will form in about 300 million years from now. It is based on the assumption that both the Atlantic and Pacific oceans will close due to subduction along their margins. This will bring all continents together in a ring around Antarctica, which will remain at the center of the supercontinent. The Indian Ocean will also close, creating a new Himalayan mountain range. The Arctic Ocean will remain open, creating a polar sea.
- Aurica: This scenario predicts that a new supercontinent will form in about 400 million years from now. It is based on the assumption that the Atlantic Ocean will stop widening and start to close, while the Pacific Ocean will continue to shrink. This will bring Africa and Europe towards North America, but also Australia and Antarctica towards South America. The result will be a supercontinent that spans both hemispheres, with a large equatorial ocean in between.

What are the implications of a future supercontinent?

The formation of a future supercontinent will have profound effects on the Earth's climate, biosphere, and human civilization. Some of the possible implications are:

- Climate change: A supercontinent will alter the global patterns of wind, ocean currents, and precipitation. It will also affect the distribution of heat and carbon dioxide around the planet. Depending on its location and shape, a supercontinent could create extreme temperature variations, arid deserts, humid tropics, or ice-covered poles. It could also trigger ice ages or greenhouse effects, depending on the amount of volcanic activity and glaciation.
- Biodiversity loss: A supercontinent will reduce the diversity of habitats and ecosystems on Earth. It will also isolate populations of plants and animals, leading to speciation or extinction. Some species might adapt to the new conditions, while others might migrate or die out. A supercontinent could also increase the risk of mass extinctions, due to volcanic eruptions, asteroid impacts, or human activities.
- Human evolution: A supercontinent will affect the evolution and history of human beings. It will change the availability of resources, such as water, food, and minerals. It will also influence the spread of cultures, languages, and religions. A supercontinent could facilitate or hinder human migration, exploration, and colonization. It could also create or prevent conflicts, cooperation, and trade among different regions and nations.

Conclusion

In conclusion, a future supercontinent is a fascinating possibility that challenges our perception of the Earth as a stable and familiar home. Whether it is Amasia or another scenario, a future supercontinent will transform the geography of our planet and the destiny of its inhabitants. It is a reminder that we live on a dynamic and ever-changing world that has a long and complex history and an uncertain and exciting future.

Source

(1) Scientists Say New Supercontinent "Amasia" Will Form When Pacific Ocean .... https://www.ndtv.com/world-news/scientists-say-new-supercontinent-amasia-will-form-when-pacific-ocean-disappears-3414741.
(3) Supercontinent to Form in the Pacific in 200 Million Years. https://greekreporter.com/2023/07/19/supercontinent-form-pacific/.
(4) Meet Amasia, a New Supercontinent Coming to Earth in the Next 300 Million Years. https://www.msn.com/en-au/news/other/meet-amasia-a-new-supercontinent-coming-to-earth-in-the-next-300-million-years/ar-AA12TLDS.
(5) How the next 'supercontinent' will form - BBC Future. https://www.bbc.com/future/article/20220401-how-the-next-supercontinent-will-form.
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