Pangaea Ultima

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Pangaea Ultima (also Pangaea Proxima, Neopangaea, or Pangaea II) is a possible future supercontinent configuration and an alternative to the Amasia supercontinent. Consistent with the supercontinent cycle, Pangaea Ultima could occur within the next 250 million years. This potential configuration, hypothesized by Christopher Scotese, earned its name from its similarity to the previous Pangaea supercontinent.^[1]

Supercontinents describe the merger of all, or nearly all, of the Earth's landmass into a single continuous continent. In the Pangaea Ultima scenario, subduction at the western Atlantic, east of the Americas (signs of it can be seen today, the Puerto Rico Trench^{[citation needed]}), leads to the subduction of the Atlantic mid-ocean ridge followed by subduction destroying the Atlantic oceanic basin, causing the Atlantic Ocean to close, bringing the Americas back together with Africa and Europe. As with most supercontinents, the interior of Pangaea Ultima would probably become a semi-arid desert prone to temperature extremes.^[2]

1 Formation
2 See also
3 References
4 External links

[edit] Formation

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According to the Pangaea Ultima hypothesis, the Atlantic and Indian Oceans will continue to widen until new subduction zones bring the continents back together, forming a Future Pangaea. Most continents and microcontinents are predicted to collide with Eurasia, just as they did when most continents collided to Laurentia.

Around 50 million years from now, North America is predicted to have rotated slightly counterclockwise (Alaska would then be near the subtropical latitudes) and Eurasia would rotate clockwise bringing Great Britain closer to the North Pole and Siberia southward towards warm, subtropical latitudes. Africa is predicted to collide with Europe and Arabia, closing the Mediterranean Sea (completely closing the Tethys Ocean (or Neotethys)) and the Red Sea. A long mountain range would then extend from Spain, across Southern Europe (the Mediterranean Mountain Range), through the Mideast and into Asia. Some are even predicted to have peaks higher than Mt. Everest. Similarly, Australia is predicted to beach itself on the doorstep of Southeast Asia and a new subduction zone is predicted to encircle Australia and extend westward across the Central Indian Ocean. Meanwhile, Southern California and Baja California is predicted to have already collided with Alaska with new mountain ranges formed between them.

One of the most important changes predicted in the Pangaea Ultima scenario, is the beginning of subduction along the eastern coasts of North America and South America. The Atlantic Ocean is predicted to have widened, even though the Puerto Rican Trench and Scotia Arc (on the eastern edges of Caribbean plate and Scotia plate, respectively) may propagate northward and southward along the east coast of North and South America. In time, this new westward-dipping subduction zone is predicted to consume the Atlantic Ocean.

About 100 million years from now, the Atlantic ocean is predicted to stop widening and begin to shrink because a bit of the Atlantic Ocean mid-ridge will have been subducted. In this scenario, a mid-ocean ridge between South America and Africa will probably be subducted first.

In 150 million years, the Atlantic Ocean is predicted to have narrowed 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 predicted to collide along the southern margin of Australia with the Central Indian Trench and the South Australian Trench pushing Antarctica northward to Australia, which at this point is predicted to have collided with Southeast Asia. The Mid-Atlantic Ridge, the last vestige of sea floor spreading in the Atlantic Ocean, is predicted to be nearly subducted beneath eastern North America at this time. The rock layers that will contain the remnants of America's eastern seaboard would then lie atop high mountain ranges.

When the last bit of the Mid-Atlantic spreading ridge is subducted beneath the Americas, the Atlantic Ocean is predicted to rapidly close with a new Pangaea forming.

At 250 million years in the future, the Atlantic and Indian oceans are predicted to have closed. North America is predicted to have already collided with Africa, but be in a more southerly position than where it rifted. South America is predicted to be wrapped around the southern tip of Africa, with Patagonia in contact with Indonesia, enclosing a remnant of the Indian Ocean (called the Indo-Atlantic Ocean). Antarctica would then once again be at the South Pole and the Pacific will have grown wider, encircling half the Earth.

[edit] See also

[edit] References

^ Scotese, Christopher R.. Pangea Ultima will form 250 million years in the Future. Paleomap Project. Retrieved on 2006-03-13.
^ Kargel, Jeffrey S. [2004-08-01]. "New World", Mars. Springer. ISBN 1-85233-568-8.