Pangea Ultima

Geologists are using computer models to speculate where the continents are going to go in the next 100 million years. Their conclusion: the continents may again rejoin into a new Pangea -- Pangea Ultima:

Today, some of his most ambitious efforts center on envisioning how Earth might look 250 million years from now. The easy part, Dr. Scotese said, is the continents. Their masses might change shape but seldom disappear altogether because their bedrock weighs little compared with dense ocean crust. Continents literally float above the action. So do mountains. Once formed, they tend to persist, disappearing only after ages of erosion wear them down.

The difficult part, he said, is predicting the development of new subduction zones in the seabed, and in comprehending how aggressively they rearrange the land.

"It's hard to understand all the forces down there," he said. "There's probably some input from the mantle," the deep, hot, churning zone below the crust. "It probably has some say on which way the plates go."

His long-term forecast, despite the uncertainties, portrays a distant time when the world's continents come together again to form a new supercontinent, which he calls Pangea Ultima.

An animated depiction of Pangea Ultima demonstrates a bold exercise in futuristic thinking. First, the Mediterranean closes. Then -- 25 million to 75 million years from now -- Australia moves north, slamming into Indonesia and Malaysia before pirouetting counterclockwise to smash into the Philippines and then Asia, eventually merging with it.

Antarctica also moves north, shedding its icecap. Roughly 100 million years from now, it plows into the Indian Ocean, and 50 million years later wedges itself between Madagascar and Indonesia. The Indian Ocean becomes a virtual inland sea.

Meanwhile, Dr. Scotese said, the biggest tectonic change of all -- driven by a giant subduction zone -- has torn through the dark Atlantic and begun to eat up seabed, slowly closing the ocean. Some 200 million years from now, the closure forces Newfoundland to smash into Africa and, a bit later, Brazil to ram into South Africa.

The collisions gain force; 250 million years from now, the continents will have merged into a new supercontinent that encircles what remains of the Indian Ocean.

"It's more like a big donut or bagel than Pangea," Dr. Scotese noted. In looking for a name, "I tried Bagelea or Donutea but figured that would trivialize the whole experience. A friend suggested Pangea Ultima -- classy, like a fancy car. It implies that it's the last Pangea, which certainly isn't true, but it's the last one I'm going to come up with."

Read the whole thing. Make sure to check out the info graphic that shows the continental movements.