Matthew Pearsall
Geography 100
Winter 2009
Scenario One: South America—Flipped.
If the continent of South America had broken off from the super-continent of Pangaea in
the exact opposite shape that it currently holds, it would be a decidedly different place than it is
today. While such things as ocean currents and prevailing winds—which are dictated more by
the rotation of the Earth—would remain the same, the geography of South America would be
radically different. This change in geography would, in turn, have a significant affect on the
weather of the continent, which would have an affect on what types of ecosystems would
emerge, and which would finally affect how human civilization developed across South
America.
The most profound difference between what is South American and what it would be, if it
were ‘flipped’ is in its geography. Gone would be the Andes range, stretching from the far north
to the far south. The Andes are a product of volcanic activity created by the subduction of the
oceanic Nazca plate under continental South American plate. While these two plates would still
collide, the mountains they produce would be very different. A very large mountain range—
similar in height to the Andes—would emerge in what would be Western Brazil (in an inverted
world). This range would fill much of the ‘point’ of Brazil, but would not extend very far north
or south along the South American coast. Instead, a chain of volcanic islands—similar to those
found in the Suth Pacific—would emerge stretching both north and south of the ‘point’ of
Brazil. Another volcanic mountain range would emerge on the northern tip of South America,
where the South American and Caribbean plates converge, similar to the mountains that are
presently located there.
This rearrangement of the mountains of South America would have a great affect on the
distribution of water across the continent. The absence of a large north-south mountain range
would eliminate the rain shadow effect along most of the western coast. Where today there are
extensive dry deserts to the west of the Andes in central South America and to the east of the
Andes in the south, there would instead by extensive prairies. The Mediterranean climate of
southern Chile would extend across into southern Argentina and, likewise, the climate of
northern Argentina would spread across into northern Chile. Only far western Brazil would still
have deserts caused by the rain shadow of the mountains. The area of central Brazil through to
the Atlantic coast would still be tropically warm, and would still be watered by the Southeast
Trade Winds coming off of the Atlantic. The massive Amazonian river basin, however, would
be absent, as the waters of the Andes would be able to drain off to the north and the east.
Without that massive drainage basin, the Amazon rain forest would be significantly drier than it
is today, perhaps similar to the climate of Mozambique and Tanzania.
All of this would have a significant affect on how humans settled South America. Instead
of large empires forming in sub-tropical Andes—where the weather was cool enough to promote
settled agriculture—the first humans in South America may have spread out to the east, in the
now drier and more hospitable Amazon. This large, wet plain would have been much more
conducive to large-scale agriculture and irrigation; perhaps leading to the rise of major river
empires such as those that rose up in Mesopotamia. Also, the Spanish conquest of South
America would have taken a very different shape. The Spanish were mostly interested in South
America's mineral wealth. In this scenario, much of that wealth is located in the off-shore island
chains. Without the wealth of gold and silver, would the Spanish have bothered colonizing
South America at all? For that matter, with the major empires of South America now oriented
towards the East, might they have instead sailed across the Atlantic and colonized Spain,
instead?
Scenario Two: Arica, Chile.
The waters of the Pacific Ocean off of Northern Chile are rich in marine life. Fishermen
in the region around Arica produce a large portion of the anchovies consumed world-wide.
Anchovies thrive in this region due to the presence of the Humbolt Current, which draws cool,
nutrient rich water up from lower levels of the ocean. The nutrients in this water feed large
quantities of phytoplankton, which in turn feed the large numbers of fish in the area. These
fisheries, however, are vulnerable to changes in water temperature. Anchovies are a cool-water
fish, and when water temperatures rise anchovy populations diminish. Unfortunately for the
fishermen of Arica, the waters off the coast are periodically subject to El Nino. El Nino refers to
a change in ocean currents which happens every few years wherein the flow of cool water
diminishes—and sometimes even reverses—raising the temperature of the water. This change in
temperature can have a devastating affect on fish populations, and consequently on the fishermen
who depend on them.
There is also reason to believe that other factors may be contributing to a further rise in
the temperature of the waters off of Northern Chile. The area of the Southeast Pacific is covered
by a huge sheet of stratocumulus clouds stretching almost 2,000 kilometers. These clouds shade
the ocean from the sun and contribute to keeping the water temperatures cool. Aerosols in the
atmosphere affect how these clouds form, and how water precipitates out of them. As the level
of aerosols in the air increases due to human activity, they affect the formation of these clouds.
All of this contributes to the unpredictability of the fish harvest for the citizens of Arica.
What can they do to better weather the ups and downs of fish yields? The most obvious answer
is for the local Aricans to diversify their economy, so that they will not be so heavily impacted
by a bad fish harvest. Encouraging tourism may be an excellent source of revenue for the city.
Arica is an old colonial port, with some fine old architecture present. Arica is also sandwiched
between the Atacama Desert and some fine surf breaks on the Pacific coast. Between these three
attractions there are many different types of tourists who could be brought into the region.
Managed properly, tourism can bring in a large amount of income while having minimal impact
on the local environment.
Arica is also situated in a region of intense winds. The air currents of the Hadley Cell hit
the Andes Mountains and rush northward. These winds are both strong and consistent, and may
be an excellent source of wind-power generation for both Chile and Peru. There are many
hurdles that would be involved in tapping the energy potential of the wind—including the
necessity of a large capital investment upfront—but it could possibly be an opportunity to be on
the leading edge of new ‘green’ technologies.
Finally, the citizens of Arica could seek to diversify within the industries already present.
This is the most prosaic approach, but perhaps the most affective. The Atacama Desert is a
major mineral resource in Chile, and the ores extracted from there need to be shipped out by sea.
Arica already serves as a mineral export port, but with investment in infrastructure Arica could
make itself a more attractive port, drawing in more of the shipping business, and thereby
diversify their economy. Finally, the fishermen of Arica could continue to fish as they always
have, but explore fishing for other species when El Nino saps the anchovy population. Sardines
are a warm water fish and, when El Nino causes the anchovy population to drop it also allows the
sardine population to rise. By shifting from anchovy to sardine harvesting during periods of
warmer water, the fishermen of Arica can continue in their own occupation without interruption.