Transcript
NARRATOR
The floor of the Atlantic Ocean is split in two by an immense volcanic mountain chain that winds, unbroken, for 45 000 miles around the globe. In places, it's riven by great fissures, from which superheated water loaded with dissolved minerals blasts into the icy depths. Clouds of sulphides solidify into towering chimneys as tall as a three-storey house.
At 400 degrees, this scalding cocktail of chemicals would be lethally toxic to most forms of life. But astoundingly, a particular kind of bacteria thrives here, and feeding on the bacteria, vast numbers of shrimps. So, beyond the farthest reach of the Sun's power, a rich, independent community exists that draws all its energy directly from the Earth's molten core.
On the other side of the planet, in the Western Pacific, bordering Japan, the dragon chimneys, another series of hot vents erupting in the darkness. Here, more but different bacteria thrive in a similar way. And here, too, more crustaceans, but quite different species from those around the hot vents in the Atlantic.
These are squat lobsters, clad in furry armour, jostling with one another beside the jets of superheated water for the best places from which to graze on bacteria. These vents, too, like those in the Atlantic, are isolated oases, so widely separated that each community is unique.
Cross to the other side of the Pacific to the deep, near the Galapagos Islands, and there are yet other fissures venting superheated water. One and one-half miles down, at a site known as 9 North, towering chimneys support a spectacular display of giant tube worms. These vents give off so much energy that some of the worms reach three metres in length. They're the fastest growing marine invertebrates known. All told, over 50 different species have so far been found living here.
The inhabitants of these bustling communities may grow at speed, but their existence can also be short, for the vents do not erupt indefinitely. Suddenly, unpredictably, they may become inactive.
Nine months have passed at 9 North. What were only recently chimneys teeming with life have turned into cold, sterile mineral monuments. Some eddy deep in the Earth's crust diverted the volcanic energy elsewhere, and an entire micro world was extinguished.
In places, volcanoes have erupted to build great submarine mountains. There are thought to be around 30 000 such volcanoes. Some, measured from the seafloor, are taller than Everest.
Sheer cliffs soaring to drowned volcanic peaks.