Earth Story 3. Ring of Fire (1 of 21)

Earth Story

Episode 3: Ring of Fire
The Pacific Ocean is rimmed by a chain of active volcanoes, arranged in a series of graceful arcs and extending 30,000 kilometres from New Zealand through Fiji, New Guinea, the Philippines, Japan, the Aleutian Islands, and down the west coast of the Americas to Patagonia. This necklace of volcanoes, continually rocked by earthquakes, has been christened the 'Ring of Fire'. Scientists exploring the link between the Pacific Ocean and the earthquakes and volcanoes which surround it have formulated a remarkable theory, plate tectonics, which explains not only how the outer part of the Earth works, but how the continents themselves, and the mineral wealth they contain, were first formed and continue to grow.

MANNING: The High Andes of Bolivia.
In the 16th century, rumours of fabulous wealth drew Spanish adventurers to this lonely place.
What they found here exceeded their wildest dreams: A mountain of silver they called the Cerro Rico.
To the Spanish, the Cerro Rico was a gift from God.
It yielded tens of thousands of tons of silver, enough to finance the entire Spanish Empire.
But why should so much mineral wealth be concentrated in one spot? And it's not just here.
All around the Pacific Ocean, there are rich deposits of copper, silver and gold.
In fact, you might call the rim of the Pacific the Ring of Gold, but it's more usually called the Ring of Fire because all around the margin of the Pacific basin, associated with the mineral deposits, there are huge chains of volcanoes.
(RUMBLING) At first sight there might not seem to be any connection between volcanoes and mineral wealth, but in fact there is.
And that link gives us a clue to one of the most puzzling mysteries about the Earth.
How did the dry land, the continents on which we live, how did they form?
Three-and-a-half billion years ago, our planet was covered by a single vast ocean.