Map of Plate Tectonics 50 Million Years in the Future

Abstract

This map of plate tectonics 50 million years in the future was created by projecting present-day plate motions into the future. The northward movement of Australia and Africa will result in the collision of Australia with China and the closure of the Red Sea, Gulf of Aden, and Mediterranean. New subduction zones start in the Indian Ocean (Capricorn trench) and along the eastern coasts of North America and South America. The Atlantic subduction zone will consume the western half of the Atlantic Ocean and eventually will consume the Mid-Atlantic Ridge. The northern portions of the Central Indian Ridge will be subducted beneath the Capricorn Trench. When the Mid-Indian Ridge is eventually subducted, Antarctica will be pulled northward to join Australia and the new "Afroaustralasian" supercontinent.

There are three reasons why I do not show the East African rifts opening into a new ocean:
- Often, oceans open around a three-armed rift system called a “triple junction”. Only two arms of a triple junction open to form ocean basins. . In the case of East Africa, the Red Sea and Gulf of Aden are the two successful rifts. The East African rift system, starting at the Afar Triangle, in Ethiopia is an aulacogen or “failed arm” of a triple junction The East African rift system is a failed rift, much like the Benue Trough in the South Atlantic or the Labrador Sea in the North Atlantic.
- Let’s step back and ask the question, “What caused the rifting of the Red Sea , Gulf of Aden and East Africa in the first place? Though the Afar hotspot certainly helped to weaken the lithosphere, The driving force that caused the rifting was the subduction (beneath Eurasia , i.e., Iran) of oceanic crust attached to the northern margin of Arabia. (There was ocean an ocean between Arabian and Iran.) This subducting slab “pulled” Arabia northward tearing it away from Africa. This subduction zone has been completely destroyed by the collision of Arabia and Eurasia (Zagros Mountains). Consequently, there is no longer any “plate tectonic forces” acting on the African rifts and they will not continue to open.
- Also, if we look at the plate tectonic neighborhood of East Africa, we see that the dominant motion of plates in the western Indian Ocean is N-S, rather than E-W . In fact, a new subduction zone is just beginning in the central Indian Ocean (a zone of diffuse earthquakes ~ 5-10 S) that will continue to pull Australia and Antarctica northward towards Asia. In other words, there is no room for East Africa to expand towards the east. Rather the east coast of Madagascar will become a strike-slip margin accommodating the continued, northward movement of the Australian-Antarctic plate.
I hope this explanation is helpful. Of course all of this is scientific speculation, we will have to wait and see what happens, but this is my projection based on my understanding of the forces that drive plate motions and the history of past plate motions. Remember: “The past reveals patterns; Patterns inform process; Process permits prediction.”

Chris Scotese
Director, PALEOMAP Project