Ultima
Pangea
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)