expanse of land began to break apart and drift in separate ways, creating the Atlantic Ocean as North America split away from Europe and South America from Africa. By 120 million years ago, the southern continents broke apart as well, with Africa, Antarctica, India, and Australia moving in divergent directions and culminating in the continental positions of the modern world.

Given the large number of years that Earth has existed, it is no surprise that the continents have wandered extensively through time. We believe this wandering will not end any time soon, and thus we can confidently predict that continental drift will continue. Furthermore, there is enough information from present-day drifting to allow prediction of future motions. Future motion will have enormous effects on future climate and on the fate of future life.

The best scenarios for understanding future continental change come from labs and analyses that have studied and modeled past motions. We fully expect future directions and rates of plate movements as measured in the present-day to continue into the future. While geographic reconstructions become more problematical and error prone the farther into the future we look, there is good agreement for at least the next 250 million years among the several independent groups of investigators who have examined this problem. The most detailed examination of future continental positions comes from C. Scotese and his Paleomap Project. For nearly two decades Scotese and his coworkers have been compiling maps of continental position in the past and have recently turned their attention to the future. They have arrived at 10 reconstructions of plate positions for the next 250 million years. They are convinced that at the end of this vast period of time there will again be a supercontinent, a return to the state last experienced by Earth at the end of the Paleozoic Era some 250 million years ago.

A WORLDWIDE BLACK SEA

For the next few million years, plate motions should continue in the current directions. The Atlantic Ocean will continue to widen, and the Pacific Ocean will continue to close. But then we can expect major changes. By 50 million years from now a world map would show fantastic differences from the present-day, and these continental positions



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