Trascrizione
We are in front of a very colourful map, from which you can begin to understand the many hidden differences in the immaculate model we encountered in the previous room. This is a tectonic map in which are represented the movements of the lithospheric plates, which are the outer rigid layer of the Earth. In red, you will find marked the Insubric Line or Tonale Fault - that's right! Here you can see how extensive the phenomenon seen - on a small scale - in Showcase 1, can be.
The Insubric Line is an important contact line that crosses the Alps and roughly divides the region into two parts: the South Alpine to the south, that is the Southern Alps, and the Pennidic and the Australpine to the north, that is the actual Alps. Its scientific name would be a tectonic line or, as we saw in Showcase 1, a fault, because it is the line that allows us to recognize the movement between two plates - the European one, of which the Insubric Line forms the southern boundary, and the African one. I will talk to you in more detail about this collision, and about the folding that gave rise to the Alps in a process called orogenesis, in the next room.
For now, I can tell you that the Insubric Line is very ancient, about 90 kilometres deep, and it has reactivated several times during the formation of the Alpine chain, but seems to have remained dormant in recent times, let's say in the last 2.5 million years. I know it's hard to grasp when we talk about millions, even billions of years. But perhaps this comparison can help: imagine that the age of our planet Earth, 4.5 billion years, corresponds to the age of a person, let's call her Gea, who is 45 years old. The Insubric Line, in Gea's life, has been inactive in the last nine and a half days of her life. That's why in geology, 2.5 million years are considered "recent times"!