Name: 【TED】深入地表之下，發現美與科學｜Francesco Sauro｜TED Talks (【TED】Deep Under the Earth's Surface, Discovering Beauty and Science | Francesco Sauro | TED Talks)
Uploaded: 2021-01-14T05:50:13.000Z
Duration: 14 min 38 s
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poorly understood, and the stuff of legends.

But it is made also of dramatic landscapes

and it is rich with surprising biological and mineralogical worlds.

Thanks to the efforts of intrepid voyagers in the last three centuries --

actually, we know also thanks to satellite technology, of course --

we know almost every single square meter of our planet's surface.

However, we know still very little about what is hidden inside the earth.

Because a cave landscape, like this deep shaft in Italy, is hidden,

the potential of cave exploration -- the geographical dimension --

Because we are creatures living on the surface,

our perception of the inner side of the planet

However, since systematic cave exploration started about one century ago,

we know actually that caves exist in every continent of the world.

A single cave system, like Mammoth Cave, which is in Kentucky,

can be as long as more than 600 kilometers.

And an abyss like Krubera Voronya, which is in the Caucasus region,

actually the deepest cave explored in the world,

can go as far as more than 2,000 meters below the surface.

That means a journey of weeks for a cave explorer.

So karstic regions are areas of the world

where the infiltrating water along cracks, fractures,

forming a drainage system of tunnels, conduits --

Karstic regions cover almost 20 percent of the continents' surface,

and we know actually that speleologists in the last 50 years

have explored roughly 30,000 kilometers of cave passages around the world,

But geologists have estimated that what is still missing,

is something around 10 million kilometers.

That means that for each meter of a cave that we already know,

there are still some tens of kilometers of undiscovered passages.

That means that this is really an endless continent,

and we will never be able to explore it completely.

And this estimation is made without considering other types of caves,

like, for example, inside glaciers or even volcanic caves,

which are not karstic, but are formed by lava flows.

And if we have a look at other planets like, for example, Mars,

However, I will show to you now that we do not need to go to Mars

I'm a speleologist, that means a cave explorer.

And I started with this passion when I was really young

in the mountains not far from my hometown in North Italy,

in the karstic regions of the Alps and the Dolomites.

But soon, the quest for exploration brought me to the farthest corner

of the planet, searching for new potential entrances

And in 2009, I had the opportunity to visit the tepui table mountains,

which are in the Orinoco and Amazon basins.

These massifs enchanted me from the first time I saw them.

They are surrounded by vertical, vertiginous rock walls

with silvery waterfalls that are lost in the forest.

They really inspired in me a sense of wilderness,

with a soul older than millions and millions of years.

And this dramatic landscape inspired among other things

also Conan Doyle's "The Lost World" novel in 1912.

Scientists consider those mountains as islands in time,

being separated from the surrounding lowlands

They are surrounded by up to 1,000-meter-high walls,

resembling a fortress, impregnable by humans.

And, in fact, only a few of these mountains have been climbed

These mountains contain also a scientific paradox:

which is a very common mineral on the earth's crust,

and the rock made up by quartz is called quartzite,

and quartzite is one of the hardest and least soluble minerals on earth.

So we do not expect at all to find a cave there.

Despite this, in the last 10 years, speleologists from Italy,

Slovakia, Czech Republic, and, of course, Venezuela and Brazil,

have explored several caves in this area.

To understand this contradiction, we have to consider the time factor,

because the history of the tepuis is extremely long,

starting about 1.6 billion years ago with the formation of the rock,

and then evolving with the uplift of the region 150 million years ago,

after the disruption of the Pangaea supercontinent

So you can imagine that the water had tens or even hundreds of millions of years

to sculpt the strangest forms on the tepuis' surfaces,

but also to open the fractures and form stone cities, rock cities,

fields of towers which are characterized in the famous landscape of the tepuis.

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【TED】深入地表之下，發現美與科學｜Francesco Sauro｜TED Talks (【TED】Deep Under the Earth's Surface, Discovering Beauty and Science | Francesco Sauro | TED Talks)

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