Aurica: two closing oceans and a new one
Aurica is a scenario in which both the Atlantic and Pacific close. At the same time, a new ocean develops through modern Asia. It demonstrates that forming another supercontinent need not involve choosing only one of today's two great basins to close.
Open Aurica 250 million years ahead. In this version, continents gather at low latitudes, with Australia near the interior of the assembly. That is the outcome of particular assumptions, not an already established future location for Australia.
Where did the idea come from?
Duarte, Schellart and Rosas (2018, published online in 2016) proposed a conceptual model involving the development of Atlantic subduction. They considered simultaneous consumption of lithosphere in both oceans rather than restricting the future to an Atlantic-or-Pacific choice.
Old oceanic lithosphere cools and can become denser than the material beneath it, but density alone does not determine where subduction begins. Plate strength, stresses and existing boundaries also matter. The scenario therefore requires a particular reorganisation, rather than merely the passage of time.
Why is a new ocean needed?
Earth remains approximately the same size in this description. As lithosphere is consumed in some places, new lithosphere must form elsewhere. Aurica gives a major role to a new system dividing present-day Asia, often called the Pan-Asian Ocean.
This is a substantial geographical assumption. A large connected landmass today need not remain a rigid block throughout the distant future. Conversely, drawing a rift in an animation does not demonstrate that it will open at the displayed location and time.
What does the model calculate?
Davies, Green and Duarte (2018) constructed comparable pathways for several future assemblies, including Aurica. Our map shows the grids the authors built from these maps in 2020. It does not solve the physics of Asian rifting or mantle flow as the animation runs.
The grids show land every 20 million years. Nothing is drawn between frames, and the frames themselves do not predict future national borders or local deformation of the crust.
Continental location affects climate
A team described by NASA GISS in 2021 compared climate simulations for Aurica and polar Amasia. Continental location, elevation and assumed atmospheric conditions affected the results. Such experiments explore how geography influences climate even when the future geography itself is uncertain.
Our map colours do not represent those climate calculations. They only distinguish land from shelves. Compare Aurica with Novopangea and Pangaea Ultima to examine different mechanisms, or with Amasia to compare the location of the whole assembly. We assign no percentage probabilities to these possibilities.