Amasia (supercontinent)

Amasia is a theoretical future supercontinent predicted to form through the slow but continuous movement of the Earth’s tectonic plates. It is expected that the continents of the Northern Hemisphere, primarily Asia and North America, will merge near the Arctic region, creating a massive landmass similar in scale to previous supercontinents such as Pangaea, Rodinia, and Nuna. The concept of Amasia arises from ongoing geological and geophysical research into the Earth’s plate tectonics, mantle dynamics, and continental drift processes.

Background and Concept

The theory of continental drift, first proposed by Alfred Wegener in the early 20th century, laid the foundation for understanding how continents move across the Earth’s surface. Over hundreds of millions of years, the Earth’s landmasses have assembled and broken apart repeatedly in a cycle known as the supercontinent cycle. Each supercontinent persists for several hundred million years before splitting due to the convective forces in the mantle.
Amasia is theorised to be the next stage in this cycle. Based on plate motion projections, scientists believe that the continents currently surrounding the Pacific Ocean are slowly converging towards each other, and in approximately 200–300 million years, they will coalesce to form a new supercontinent. The name “Amasia” reflects the predicted fusion of America and Asia, which are expected to play the central role in its formation.

Geological Basis and Plate Movements

The formation of Amasia is influenced by the movement of several major tectonic plates, including the Pacific Plate, North American Plate, Eurasian Plate, and Indo-Australian Plate. The Pacific Ocean, which currently occupies a large portion of the Earth’s surface, is gradually shrinking due to subduction zones along its margins. The Ring of Fire, a region of intense volcanic and seismic activity encircling the Pacific, is a key indicator of this process.
Several geological models predict different scenarios for the closure of the Pacific Ocean:

• Introversion model: Suggests that Amasia will form through the closing of the Pacific Ocean, causing the Americas to collide with Asia near the Arctic.
• Extroversion model: Proposes that the Atlantic Ocean may close instead, leading to the reassembly of the continents around the current antipodal side of Pangaea.
• Orthoversion model: Suggests that Amasia may form at a 90° angle to the position of the last supercontinent, Pangaea.

Among these, the introversion model has gained more support, as the Pacific is currently contracting faster than the Atlantic is widening.

Predicted Geography and Formation Process

Amasia’s formation will likely involve the northward movement of the Americas, driven by the motion of the Pacific Plate and subduction zones along its western boundaries. As North America drifts towards Asia, the Arctic Ocean is expected to close, forming mountain ranges and inland seas similar to those seen in previous continental collisions. Antarctica, which currently lies over the South Pole, may remain largely isolated, while Australia is projected to drift northwards, potentially colliding with East Asia and contributing to Amasia’s southern edge.
Computer simulations suggest that the resulting supercontinent will be centred near the North Pole, giving Amasia a predominantly cold and dry climate. The new continental configuration will have profound effects on global ocean circulation, atmospheric patterns, and biodiversity.

Comparison with Past Supercontinents

Amasia would be the latest in a sequence of supercontinents that have shaped Earth’s geological and biological history. Major examples include:

• Columbia (Nuna): Formed approximately 1.8 billion years ago.
• Rodinia: Assembled around 1.1 billion years ago and broke apart about 750 million years ago.
• Pannotia: Existed roughly 600 million years ago.
• Pangaea: Formed around 335 million years ago and began breaking apart about 175 million years ago.

Each supercontinent’s formation and breakup have significantly influenced global climate systems, sea levels, and the evolution of life. The cycle is estimated to occur roughly every 500–700 million years.

Environmental and Biological Implications

If Amasia forms as projected, it will drastically alter Earth’s geography and ecosystems. The interior of such a vast landmass would likely be dominated by arid deserts due to limited moisture from the oceans. Coastal regions, in contrast, would experience more temperate climates. The reorganisation of continents will also impact ocean currents and heat distribution, potentially causing major climatic shifts.
These changes will have profound implications for biodiversity. Historically, supercontinent assembly has led to large-scale extinctions due to habitat loss, reduced coastal environments, and climatic extremes. Conversely, their breakup phases have often triggered rapid speciation as isolated populations adapt to new environments.

Scientific Studies and Technological Models

Recent research using geophysical models, palaeomagnetic data, and plate reconstruction software such as GPlates has improved predictions about Amasia’s development. Satellite-based observations of current plate movements provide measurable data that support the ongoing convergence of the Pacific margins. Additionally, mantle convection simulations reveal that the locations of supercontinent assembly may correlate with deep mantle structures called large low-shear-velocity provinces (LLSVPs), suggesting a potential cyclic pattern in continental rearrangement.

Alternative Theories and Debates

While the Amasia model is widely accepted, it is not without controversy. Some scientists propose alternate future supercontinent scenarios, including:

• Novopangaea: A model where the Atlantic closes instead of the Pacific, resulting in a supercontinent resembling Pangaea.
• Aurica: Suggests simultaneous closure of both the Pacific and Atlantic Oceans, leading to a supercontinent forming near the equator.