Continents in Collision

Creeping more slowly than a human fingernail grows, Earth's massive continents are nonetheless on the move.

The Earth is going to be a very different place 250 million years from now.

Africa is going to smash into Europe as Australia migrates north to merge with Asia. Meanwhile the Atlantic Ocean will probably widen for a spell before it reverses course and later disappears.

Two hundred and fifty million years ago the landmasses of Earth were clustered into one supercontinent dubbed pangaea. As Yogi Berra might say, it looks like "deja vu all over again" as the present-day continents slowly converge during the next 250 million years to form another mega-continent: Pangaea Ultima.

The surface of the Earth is broken into large pieces that are slowly shifting -- a gradual process called "plate tectonics." Using geological clues to puzzle out past migrations of the continents, Dr. Christopher Scotese, a geologist at the University of Texas at Arlington, has made an educated "guesstimate" of how the continents are going to move hundreds of millions of years into the future.

"We don't really know the future, obviously," Scotese said. "All we can do is make predictions of how plate motions will continue, what new things might happen, and where it will all end up." Among those predictions: Africa is likely to continue its northern migration, pinching the Mediterranean closed and driving up a Himalayan-scale mountain range in southern Europe.

What's it like to see two continents collide? Just look at the Mediterranean region today.

Africa has been slowly colliding with Europe for millions of years, Scotese said. "Italy, Greece and almost everything in the Mediterranean is part of (the African plate), and it has been colliding with Europe for the last 40 million years."

That collision has pushed up the Alps and the Pyrenees mountains, and is responsible for earthquakes that occasionally strike Greece and Turkey, Scotese noted.

"The Mediterranean is the remnant of a much larger ocean that has closed over the last 100 million years, and it will continue to close," he said. "More and more of the plate is going to get crumpled and get pushed higher and higher up, like the Himalayas."

Australia is also likely to merge with the Eurasian continent.

"Australia is moving north, and is already colliding with the southern islands of Southeast Asia," he continued. "If we project that motion, the left shoulder of Australia gets caught, and then Australia rotates and collides against Borneo and south China -- sort of like India collided 50 million years ago -- and gets added to Asia."