Pangaea Proxima

Pangaea Proxima (also called Pangaea Ultima, Neopangaea, and Pangaea II) is a possible future supercontinent configuration. Consistent with the supercontinent cycle, Pangaea Proxima could form within the next 250 million years. This potential configuration, hypothesized by Christopher Scotese in November 1982, earned its name from its similarity to the previous Pangaea supercontinent. Scotese later changed Pangaea Ultima (Last Pangaea) to Pangaea Proxima (Next Pangaea) to alleviate confusion about the name Pangaea Ultima which could imply that it would be the last supercontinent.^[1] The concept was suggested by extrapolating past cycles of formation and breakup of supercontinents, not on theoretical understanding of the mechanisms of tectonic change, which are too imprecise to make predictions that far into the future. "It's all pretty much fantasy to start with," Scotese has said. "But it's a fun exercise to think about what might happen. And you can only do it if you have a really clear idea of why things happen in the first place."^[2]

Supercontinents describe the merger of all, or nearly all, of

About 125 million years from now, the Atlantic Ocean is predicted to stop widening and begin to shrink as the Mid-Atlantic Ridge seafloor spreading gives way to subduction. In this scenario, the mid-ocean ridge between South America and Africa will probably be subducted first; the Atlantic Ocean is predicted to narrow as a result of subduction beneath the Americas. The Indian Ocean is also predicted to be smaller due to northward subduction of oceanic crust into the Central Indian trench. Antarctica is expected to split in two and shift northwards, colliding with Madagascar and Australia, enclosing a remnant of the Indian Ocean, which Scotese calls the "Medi-Pangaean Sea".^[7][8]

When the last of the Mid-Atlantic Ridge is subducted beneath the Americas, the Atlantic Ocean is predicted to close rapidly.^[9] Research by Duarte et al in 2024 is consistent with this, noting that the Gibraltar Arc may evolve into a subduction zone entering the Atlantic Ocean and forming an Atlantic analogue to the current Ring of Fire, leading to the closure of the Atlantic Ocean.^[10]

At 250 million years in the future, the Atlantic is predicted to have closed, with only small vestiges of the former ocean remaining. North America will have collided with Africa, but be in a more southerly position than where it rifted away. South America is predicted to be wrapped around the southern tip of Africa and Antarctica, completely enclosing the Medi-Pangaean Sea, which will become a supertoxic inland sea that begins to poison the surrounding oceans, lands and atmosphere, leading to another great extinction event.^[7] The supercontinent will be encircled by a global ocean, the Neopanthalassan Ocean (meaning "new" Panthalassan Ocean),^[7] which encircles half the Earth.^[9] The Earth is expected to have a hothouse climate with an average global temperature of 28 °C (82 °F).^[7] The only areas likely to be suitable for known life are those closest to the poles (modern-day Western Europe).^[4]

Effects

The formation of Pangaea Proxima will probably dramatically affect the environment. The collision of plates will result in mountain building, thereby shifting weather patterns. The

Pangaea Proxima could also insulate the

There are two models for the formation of Pangaea Proxima — an early model and the current model. The two models differ in where they place Australia, Antarctica, and Chukotka.

The early model, created in 1982 and shown on the Paleomap Project website, places Australia and Antarctica connected to each other as a separate landmass to Pangaea Proxima, close to the South Pole, and Chukotka staying with Eurasia.

The current model, created in 2001 and shown on Christopher Scotese's YouTube channel,^[13] has Australia attached to China, East Antarctica attached to South America, and West Antarctica attached to Australia, with Chukotka and the Kamchatka Peninsula attached to North America (Chukotka is on the North American plate; while the Kamchatka Peninsula could either lie on the North American plate or be part of a separate Okhotsk microplate).

Other suggested future supercontinents

Paleogeologist Ronald Blakey has described predictions of the next 15 to 85 million years of tectonic development as fairly settled, without supercontinent formation.^[14] Beyond that, he cautions that the geologic record is full of unexpected shifts in tectonic activity driven by currents deep in the Earth's mantle which are largely undetectable and poorly understood, making longer projections "very, very speculative".^[14] In addition to Pangaea Proxima, two other hypothetical supercontinents—"Amasia" and "Novopangaea"—were illustrated in an October 2007 New Scientist article.^[15] Another supercontinent, Aurica, has been suggested in more recent times.

New research from Curtin University in Australia and Peking University in China supports an Amasia scenario within 200 to 300 million years. The study in the National Science Review suggests that the Pacific Ocean, shrinking since the time of the dinosaurs, may continue until it has closed entirely, resulting in the collision of the Americas with Eurasia.^{[citation needed]}

See also

• The Future Is Wild, television series which explores future evolution, including on Pangaea Proxima
• Pikmin, a series of video games revolving around tiny aliens visiting a distant future Earth that features maps based on the 1982 model

References