Two hundred and fifty million years ago, the surface of the Earth presented a very different face. We're not talking here about climate, although that was probably very different from what we now have, but the map of the continents themselves. Or maybe that should be written in the singular, because their really was only one big land mass, which geologists call "Pangea", meaning all (pan) of the land (gea) there was. Through the process of plate tectonics, which sees land (and sea bottom) as being only solidified crust floating around on the earth's molten core, this one great land mass gradually broke into chunks which drifted apart to form the shape of the major continents as we recognize them today. Volcanoes erupt where this molten core breaks through. Mountain chains form where these continental plates collide. And this whole process is still going on today.
So what comes next? Based on present measurements of continued continental drift, geologists who are part of the "Paleomap" project have recently come up with a projected map of what the Earth will look like two hundred and fifty million years from now. (See NASA's "astropix" webpage for Sept. 22, 2007.) Except for Australia and Antarctica, which will have joined together, while New Zealand, the Philippines and Japan and some other of the western Pacific islands, as well as Ireland and England (by then become arctic islands) will continue their insular independence, the rest of the Earth's continents will have drifted back together to form one huge new land mass, which these scientists have called "Ultima Pangea" -- although none can say for sure how ultimate it will be, because who knows what will happen when the Sun reaches its "red giant" stage several billions years from now?
But even if what they call "ultimate" proves to be only temporary, it will be a strange looking map indeed. North and South America will be scrunched into each other and Africa drifted northwestward to occupy where the North Atlantic Ocean once was. The only major ocean, in fact most of the rest of the globe will be covered by a greatly expanded Pacific Ocean, while southeast Asia will reach around to touch the southern tip of the two Americas with India becoming the biggest peninsula jutting into a smaller inland sea. A new mountain range, the Mediterranean Mountains, will appear roughly where the sea by that name once was.
Will the human race survive long enough to see these changes? Obviously there will be major climate change, considering that what had been north Africa and western Europe will then be farther north than Siberia and the Canadian arctic. As an extremely adaptable species, there is no reason that humans might not survive for many millions of more years. Considering that the changes caused by continental drift (not counting earthquakes, tsunamis, and volcanic eruptions) are very slow, humans should be well able to cope, even though it is obvious that major adjustments (population migrations and other adaptations) can be and will have to be made. The big question, instead, is whether life, or significant portions of it, can survive a more sudden even more catastrophic change.
There have been at least five major extinctions of a significant portion of life forms on this planet during its four and a half billion year history. The last major one, which wiped out the dinosaurs about sixty-five million years ago, may have had an extraterrestrial cause (a huge asteroid or meteor causing sudden atmospheric pollution and cooling so severe that larger forms of terrestrial life than insects and small mammal, amphibians, birds, etc., could not survive). Now something just the opposite (human produced run away global warming) seems in the works. The tragic irony will be if we, as among the most adaptable, and clearly the most intelligent species (able even to figure out how much the map of the earth has changed and will change over billions of years) fail to muster the collective will power to make even the relative minor adjustments that are needed to prevent such a catastrophe.
R W Kropf 9/23/07 Pangea.mss (680 words)