Kampi Flegrey, a volcano near Naples, started to wake up

The volcano Campi Flegrey, next to which is located the Italian city of Naples, began to wake up. This volcano is considered one of the largest in the world, and now the pressure of the magma beneath it, according to scientists, has reached a critical point. In fact, we are talking about the fact that the volcano can wake up at any time. And it is very dangerous not only for the inhabitants of Naples, but also for other regions of Italy.

The volcano caldera was formed 39 thousand years ago, during the largest eruption in 200 thousand years in this region. Perhaps it was this event that caused the resettlement of Neanderthals to the eastern part of the Mediterranean Sea. Now, sometimes, gases in a small amount come out of the crater, which indicates that the center of activity is still preserved under the surface. For Campi Flegrey, scientists have been observing for many years, and it seems not in vain.

In the 1950s, the surface above the caldera began to move, rising more than 3 meters since then. The caldera is an extensive circus-shaped hollow of volcanic origin, often with steep walls and a more or less even bottom. Such a depression of the relief is formed on the volcano after the collapse of the walls of the crater or as a result of its catastrophic eruption.
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In the 1980s, this process accelerated, and several earthquakes also occurred in the region. Scientists have already begun to suspect that the volcano is beginning to wake up. Nevertheless, everything ended unexpectedly, and Kampi Flegrey calmed down for several years - right up to 2005. Since then, the surface began to rise again, the level increased by 0.4 meters. Under the caldera of the volcano, magma gradually accumulates.

Due to the fluctuations of the upper crust caused by volcanic activity, the coastal part of the city of Pozzuoli plunged into the water. Now this region is located at a depth of 10 meters and is a tourist object. The part of the city, plunged to the bottom of the sea, is studied by tourists with the help of special vessels with a porthole inserted at the bottom.

As for the eruption of the volcano, it is not so easy to predict, and even regular earthquakes or gas emissions from the crater are not always a clear sign of the awakening of the “fiery mountain”. Specialists from the National Institute of Geophysics and Volcanology of Italy ( National Institute of Geophysics and Volcanology ), led by Professor Giovanni Chiodini (Giovanni Chiodini) decided to use the new method of monitoring the activity of the volcano. This method, according to experts, can serve as a reliable tool for identifying awakening volcanoes.



It consists in monitoring heat transfer from magma to nearby rocks, as a result of the release of water vapor from the magma. When the magma comes close to the surface, the pressure somewhat decreases, allowing carbon dioxide, water vapor and other gaseous compounds to go higher. Water vapor is an excellent coolant that distributes heat to nearby rocks and condenses. As the magma heats the surrounding rocks, heat flows up. The rocks are heated, their strength decreases, which leads to deformation of the overlying layers. If heating from below continues, it may cause an eruption.

Italian scientists have decided to use a computer model in order to clarify the behavior of the upwardly flowing gases and steam. When the pressure on the rocks at the point of contact between the magma and the crust reaches a critical value, gases and water vapor go up even more actively, which can be determined with the help of tools. The increase in the volume of gases “escaping” from magma, in the opinion of the Italians, is a reliable sign of the volcano being awakened.

The computer model has shown that water vapor is now being released much more actively than before. As a result, the rock layers located above the magma have already warmed up to 60 degrees Celsius. More importantly, the model demonstrated that the magma had reached critical pressure, after which the active phase of the volcano awakening begins.

Unfortunately, an accurate prediction of the time of awakening cannot be made. A volcano can wake up in a few years, or in a few decades. The model, which is used by scientists, does not allow to study the structure of the volcano in order to understand when and how the rising magma will break out. And the volcano itself is a very complex system that can both fall asleep unexpectedly and wake up no less unexpectedly. For example, cooling, gas-free magma can freeze, closing the exit to the hotter layers. The sleep period between 1984 and 2005 is an example of such a “sleep.”

Without a doubt, half a million people living near the caldera are in danger. The eruption itself will not necessarily be as powerful as 39 thousand years ago. This volcano erupted and less active, for example, in 1538 .

DOI: 10.1038 / ncomms13712