650 - Reverse Calenture: Drowning in the Sahara
From a young age, Frank was fascinated by maps and atlases, and the stories they contained. Finding his birthplace on the map in the endpapers of Tolkien's Lord of the Rings only increased his interest in the mystery and message of maps.
While pursuing a career in journalism, Frank started a blog called Strange Maps, as a repository for the weird and wonderful cartography he found hidden in books, posing as everyday objects and (of course) floating around the Internet.
"Each map tells a story, but the stories told by your standard atlas for school or reference are limited and literal: they show only the most practical side of the world, its geography and its political divisions. Strange Maps aims to collect and comment on maps that do everything but that - maps that show the world from a different angle".
A remit that wide allows for a steady, varied diet of maps: Frank has been writing about strange maps since 2006, published a book on the subject in 2009 and joined Big Think in 2010. Readers send in new material daily, and he keeps bumping in to cartography that is delightfully obscure, amazingly beautiful, shockingly partisan, and more.
Oceans and deserts are on opposite ends of the humidity scale, yet at some weird level, the extremes are interchangeable. Rolling desert dunes are reminiscent of ocean waves, and as monotonous. Not coincidentally, the main vehicle of those sandy wastes, the camel, is nicknamed the 'ship of the desert'.
Expanses of sea and sand are equally unfit for human habitation, but parallel deliria bewitch exhausted travellers into thinking otherwise. A fata morgana projects a nonexistent oasis or a phantom city on the desert horizon, while calenture  manifests itself to heatstruck sailors as green pastures surrounding their ships. Stepping overboard to their presumed salvation, these unfortunate navigators sink to a watery grave.
The Earth itself sometimes seems unsure whether dunes should be waves, or sea should be land. If the tectonic dice would have rolled slightly differently about 130 million years ago, the Sahara - now the world's largest non-polar desert  - could have been a giant stretch of water, plied by real ships. The bulk of the landmass thus displaced would now be attached to South America, providing Brazil with a giant bulge of land extending halfway to Portugal. So what happened - or rather, what didn't happen?
Before that giant dice-roll, South America and Africa were joined to Australia, Antarctica and India into a supercontinent known as Gondwanaland . That's the reason why the Brazilian and West African coastlines still seem like such a good fit – they once did fit together. The first major fragmentation of Gondwanaland occurred on what is now Africa's east coast, with East Gondwana (India/Australia/Antarctica) splitting off around 180 million years ago. About 50 million years later, South America started moving away from Africa along a fault line roughly in the shape of those two interlocking shorelines - providing Brazil's coast with its instantly recognisable knee shape, and Africa with its trademark western bulge.
Looking at the region's tectonic structure, the split as it did happen is puzzling: the West African Rift System shaped the African-South American split from both continent's southern edges right up to Cameroon (and Brazil's easternmost cape), but the rift itself then continues northward, from roughly where Nigeria is to Libya. This would have been the logical place for the rest of the split to occur. The result would have been not one Atlantic Ocean, but two distinct bodies of water, separated by Sahara-Brazil: a South Atlantic Ocean, and a Saharan-Atlantic Ocean in the north.
But, in a dramatic plate tectonic twist, a competing rift along the present-day Equatorial Atlantic margins won over the West African Rift, causing it to become extinct, avoiding the break-up of the African continent and the formation of a Saharan Atlantic ocean. So why didn't West Gondwana break along that fault line? That is the question to which scientists from the GeoForschungsZentrum (GFZ) in Potsdam and the University of Sydney have now found an answer.
A lot of number crunching  has explained why: the larger the angle between a rift zone and the direction of the fracture, the more force will be needed for it to manifest itself. Because the West African Rift is almost perpendicular to the westward pull of South America, it could only manifest itself in the southern part of the rift system. Where it met the Equatorial Atlantic Rift system, it lost out to its competitor, positioned at a much smaller angle to the continental drift.
Without that Equatorial Atlantic competitor, the West African Rift might still have been the fault line that separated two continents, giving us a much reduced Africa, and a much enlarged South America.
This map was sent in by Tom Anderson, who offers some fascinating speculations on how this other Earth might have differed from our own:
"Would the presence of a huge desert tacked onto the Amazon Delta have affected the rise of mountain-terracing and jungle-cutting civilisations of South America? Would the Gulf of Morocco, with its sheltered seas stretching from Rabat to Barbados, have been the cradle of a great seafaring culture?"
"Across the water, the corresponding absence of that land on the southern coast of the Mediterranean would surely have altered weather in that area substantially - and perhaps let the Med have substantial tides, unlike in our world. What would that have meant for the fertile crescent and the classical civilisations? Without such a cossetted physical environment, would we have had the golden of ancient civilisation that gave Europe its historical head start?"
"And with Lisbon just three weeks' sail from Lagos, would the mariners on whichever side have made contact with their respective New World centuries before our Columbus, or would Leif Ericson still have beat them to it?"
For more on the science behind this map, see this Pressemitteilung (in German) on the GFZ website, this feature on ScienceDaily, or this page on Tectonic Waters, one of the researchers' own blog. Image taken from the GFZ website.
 A desert is a land area bereft of plant and animal life due to low precipitation. Although we immediately think of the hot variety, the world's two largest deserts are extremely cold: Antarctica and the Arctic, respectively, both about 5.5 million sq. mi (14 million km2) in size. The Sahara is 3.5 million sq. mi (just over 9 million km2). ↩
 Named after an area in central India, the 'forest of the Gonds', a local tribe. ↩
 Not official scientific terminology. ↩
The stories we tell define history. So who gets the mic in America?
- History is written by lions. But it's also recorded by lambs.
- In order to understand American history, we need to look at the events of the past as more prismatic than the narrative given to us in high school textbooks.
- Including different voices can paint a more full and vibrant portrait of America. Which is why more walks of American life can and should be storytellers.
A glass of juice has as much sugar, ounce for ounce, as a full-calorie soda. And those vitamins do almost nothing.
Quick: think back to childhood (if you've reached the scary clown you've gone too far). What did your parents or guardians give you to keep you quiet? If you're anything like most parents, it was juice. But here's the thing: juice is bad for you.
Orangutans join humans and bees in a very exclusive club
- Orangutan mothers wait to sound a danger alarm to avoid tipping off predators to their location
- It took a couple of researchers crawling around the Sumatran jungle to discover the phenomenon
- This ability may come from a common ancestor
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