Atlantic Ocean to be swallowed by land
Geologists believe they have discovered the key to centuries of earthquakes near Portugal: shifting tectonic plates are edging Europe and America ever closer to a cataclysmic crunch.
Europe and America are on course for an earth-crunching collision. This is not a metaphor for politics or international relations, but the literal truth: according to new findings by geologists, the Atlantic Ocean which separates these two continents is beginning to shrink. In around 220 million years countries as far apart as Chile and China could be part of one enormous landmass.
That entire continents could migrate so far may seem like a far fetched idea. But the land beneath our feet is in fact drifting all the time. If we could go back 250 million years, we would find a planet on which almost all of the land was concentrated in a single supercontinent known as the Pangaea.
Why do these monumental changes occur? Because all the Earth’s surface, land and sea, rests on a bed of tectonic plates which float on a thick layer of molten rock. As this ‘mantle’ churns under the influence of convection currents, it behaves like a liquid conveyer belt, slowly pushing the tectonic plates together or apart.
These tectonic shifts are so slow that most of the time we do not notice them. Not so in so-called subduction zones, however: here, where two plates meet, one is forced one beneath the other and engulfed in the magma below.
Such titanic collisions have the power to convulse the surface of the Earth. And that is what first awoke the suspicion that a new subduction zone was developing: in Portugal, two catastrophic earthquakes in the past three centuries hinted at great tectonic rumblings below.
Now geologists in Australia have published a paper presenting the first solid evidence that this shift is indeed underway. If they are right, Europe and America will drift closer until they crunch together, leaving as a scar a set of mountain ranges as vast as the Himalayas.
Earth’s continents may well be converging into a second great Pangaea.
A sea change
A lot could change in 200 million years: for all we know, civilisation and even life itself will have vanished from the Earth. Still, the prospect of a one-continent world is an intriguing thought.
Do oceans divide us culturally and emotionally as well as physically? If countries had developed alongside each other instead of being separated by vast watery gulfs, would the world be a happier and more harmonious place? Humanity is at its best, some say, when we are forced to cooperate and share.
But for others the sea is in fact a blessing: what else can fortify civilisations against one another’s greed for land and dominion? If we had evolved on a Pangaea instead, they say, our history would have been one of constant war until one culture had triumphed, obliterating everything in its path.
- Would the world be a more or less peaceful place if every continent was squeezed into one?
- ‘How inappropriate to call this planet Earth when it is quite clearly Ocean.’ What does science fiction writer Arthur C Clarke mean by this? Is he right?
- Find your country on the map above (a larger version is included in the links). In pairs, list as many ways as you can think of in which life might be different in a world like this.
- Draw a simple diagram demonstrating what happens when tectonic plates collide.
Some People Say...
“Oceans are irrelevant in the age of air travel and the internet.”
What do you think?
Q & A
- How can something that is happening so slowly be news?
- Geology would certainly struggle to keep pace with the 24 hour news cycle. But that’s not to say it doesn’t matter – in fact geography is arguably the most influential factor in shaping human societies. The great French historian Fernand Braudel, for instance, argued that the ‘history of events’ was little more than a buzzing on the surface of long term environmental change.
- I don’t understand.
- Here’s an example: the earliest human civilisations developed around the Mediterranean and the Sea of Japan. Why? Because these two regions have rare features which gave them a huge advantage in agriculture and trade: large but navigable seas surrounded by land and a temperate climate perfectly suited to arable farms.
- ‘Geo’ is Greek for Earth, and geologists are people who study it.
- This word, from the same Greek root, means ‘all Earth’. Geologists believe that Earth is on a constant supercontinent cycle, with landmasses splitting apart and rejoining every 300-500 million years or so.
- Convection currents
- The mantle is heated by the Earth’s fiery core. As the magma heats it becomes lighter and rises towards the surface; but this in turn cools it and drives it down. This creates a constant current in the magma which is responsible for the movement of tectonic plates.
- The first was the Great Lisbon Earthquake of 1755, which killed tens of thousands of people. The shock caused by this event had a profound and lasting influence on European intellectual history. The second in 1969 was similarly powerful but far less destructive of human life.
- A mountain range which spans India, China, Nepal, Tibet, Bhutan and Pakistan. Some of the tallest mountains in the world can be found here, including Mount Everest.