杏吧原创

It鈥檚 hot out there (Image: WestEnd61/Rex)

If you鈥檙e looking for extreme vistas and even more extreme weather you can鈥檛 go far wrong with Pangaea. Earth鈥檚 most recent supercontinent came together about 300 million years ago and started to break apart 125 million years later. To experience it at its most extreme, set your time machine for about 250 million years ago.

The best way to begin your visit would be to hover at the edge of the atmosphere and gaze down at the vast expanse of land. The continent is C-shaped with the warm Tethys Sea nestled within the curve. From the other side of the planet all you see is an unbroken expanse of ocean, Panthalassa.

For your first stop on the surface, why not head for the equatorial desert? To experience it at its most punishing, aim for the centre of the continent close to the equator. Climb out, and where you鈥檙e standing will one day be somewhere in the western Sahara. But Earth鈥檚 greatest desert today has nothing on this one.

This point in time is just after the Permian mass extinction, which wiped out around 90 per cent of species. One proposed cause is a super-greenhouse climate, which persisted for several million years and rendered much of Pangaea鈥檚 interior uninhabitable. 鈥淚t was extraordinarily hot 鈥� it would have been the norm to have temperatures above 50 掳C,鈥� says Paul Wignall, who researches palaeoenvironments at the University of Leeds, UK. Expanses of reddish dust stretch as far as the eye can see. In the distance you can just make out the mighty Central Pangaean Mountains, unless it鈥檚 a windy day, when you鈥檒l be face-to-face with a boiling red sandstorm.

Next we recommend a quick zip east to the shores of the Tethys Sea. You鈥檙e here to marvel at Pangaea鈥檚 most extreme sight: the mega-monsoon. Monsoon rains happen when moisture-laden sea air is blown onto land and forced upwards, cooling and condensing the water to make rain.

At the edge of the Tethys, you risk getting utterly drenched. The sea was probably as warm as hot soup, about 40 掳C, says Wignall. That meant the air above it was wringing wet. On top of that, the mountains bordering the sea鈥檚 north shore were among 鈥渢he mightiest ever seen on Earth鈥�, according to geology writer Ted Nield in his book Supercontinent. That would have forced huge amounts of warm wet air up to great heights, cooling it quickly and unleashing a deluge that makes today鈥檚 monsoon in India look like a light shower. At least it would have been warm.

We know more about Pangaea than its supercontinental predecessor Rodinia (see page 30). But Earth鈥檚 tectonic plates are constantly on the move and most geologists think the continents repeatedly coalesce and split apart in a 500-million-year cycle, so there may have been many more before Rodinia. And the cycle continues: in about 250 million years the world鈥檚 land masses will come together again in a future supercontinent called Pangaea Ultima. If only our time machine went forward鈥�

Read more: 鈥�A time traveller鈥檚 guide to Earth鈥�

This article appeared in print under the headline 鈥淓xtreme deserts and torrential rains鈥�