Volcanic phenomena, some are destructive, others we don't even perceive them, some are spectacular, others instead even if we have them under our eyes we do not notice them. It's not just about explosive eruptions and particularly spectacular: when we talk about volcanic phenomena we mean many different “special effects” with truly fascinating hidden mechanisms.
Volcanic phenomena: origin
Why do these exist volcanic phenomena? It all starts from the fact that the internal temperature of the Earth increases as we get closer to its core, with a first rapid rate, of 3 ° C every 100 meters of depth, then slower, up to 4,300 ° C of the center of the Earth.
The heat generated inside our planet is resulting from the still energy of its formation or consequence of the radioactivity emitted by the various minerals present in the earth's crust.
A fraction of this heat is slowly dispersed to the outside but most of it remains inside the Earth and ensures that the materials remain in the molten state. So here is the magma that, in some areas, gives rise to one high activity called volcanic and volcanic phenomena.
Volcanic phenomena: what they are
Between main volcanic phenomena we undoubtedly find the eruptions which are then the first we think about. But let's take a step back to better understand what happens first and what are the variants.
We have the magma inside the Earth, a mixture of molten minerals also containing gas in abundance, including water vapor (70% -90%), but also carbon dioxide, sulfur dioxide, nitrogen, carbon monoxide, hydrogen, hydrochloric acid and noble gases. The gas is released together with the magma as it escapes and there is therefore a mix known as lava.
As temperatures and viscosity vary, the magma has very different physical behaviors. When magma is rich in quartz we have the phenomenon called plutons, intrusive clusters that are generated when this acid magma with high viscosity and a temperature of 700-800 ° C., rises towards the surface but cools before escaping so plutons are created.
Conversely, if the magma is low in quartz, it has low viscosity and temperatures above 1000 ° C, it goes up and out without creating these clusters. In general, all magmas erupt in the form of lava and, once it cools, it gives rise to volcanic phenomena such as effusive igneous rocks.
When a eruption, can be of type explosive or of an effusive type, at first it is a particularly violent phenomenon. There are also cases in which together with the lava it also frees itself a quantity of gas that forms a burning cloud with the volcanic waste which, when cooled, becomes ignimbrite.
Among the most dangerous volcanic phenomena, related to explosive eruptions, there is the mudslide, or "Lahar", which occurs in long-dormant volcanoes where snow or ice has accumulated.
When the eruption is effusive then they are there very fluid basaltic lavas that can flow over large distances. They are not lavas rich in gas and therefore create a sort of "Film" on the surface of the Earth which is not always perfectly smooth but can show bubbles and "cushions".
Volcanic phenomena: secondary
When we are in areas affected by heat flows of great entity, we can see secondary volcanic phenomena such as thermal springs, gas emissions and called water vapor fumaroles, shower heads and geysers according to their temperature and their "shape".
Volcanic phenomena in Italy
In Italy there are often volcanic phenomena because our country is long a line of convergence between the African and the Eurasian crustal plate. This also means that, as we all know by now, also a highly seismic region, as well as rich in volcanic phenomena. We're on the Belt of Fire, together with other countries that, like us, fear earthquakes and volcanic phenomena.
Volcanic and pseudovulcanic phenomena
To study volcanic phenomena from an early age it is possible to experiment and try to simulate them in small, but “live” fashion". There are really cool games like questor, for sale on Amazon for 16 euros, which allow young and old to build an erupting volcano.
Volcanic and seismic phenomena
There is a strait connection between seismic and volcanic phenomena, both in connection with orogeny, or the formation of mountains. These are phenomena that often occur in geologically younger lands, where the uplift of the mountains is still taking place. Both volcanoes and earthquakes are the result of fractures and movements of the earth's crust, the most external and superficial part of the Earth.
THE volcanoes focus however on the Ring of Fire, which goes from the western coasts of America, to Asia, passing through Japan to Polynesia. Earthquakes, on the other hand, are distributed evenly but occur mainly where there are fractures and tensions in the earth's crust.
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