A supervolcano has begun to stir in Italy. When will Campi Flegrei erupt? Rising ground level above the caldera

Phlegrean Fields is a district of the city of Naples, located on the shores of the Gulf of Pozzuoli. The Phlegrean Fields are located in the northwestern part of the city, bordered in the west by Cape Miseno, and in the east by Cape Posillipo. The coastal strip of the Tyrrhenian Sea is clearly visible from the mountains. The Phlegrean fields cover an area of ​​100 square kilometers. Today, this area is connected to the central part of the city via a metro line.

Supervolcano on the Phlegrean Fields today

Recently, frequent reports have appeared on the Internet and in the media that a supervolcano is coming to life in the Phlegrean Fields. You can often find headlines like this in newspapers: “A volcanic eruption will soon occur in the Phlegrean Fields of Naples!” Is it really?

Volcanologists, unfortunately, confirm such reports. Their opinion is based primarily on the fact that the volcano is beginning to show signs of activity, the temperature of the volcano is constantly increasing, and this may mean, as experts say, that magma will soon reach ground level. It is assumed that the magma chamber of this volcano is connected with the chamber of Vesuvius, the most dangerous volcano in the entire history of mankind. The degree of danger is constantly increasing, as scientists say, if an eruption occurs, it will have serious consequences, first of all, for the densely populated city, as well as for the whole of Europe. If the ground continues to rise further, the city will have to be evacuated.

History of the volcano on the Phlegrean Fields

It is believed that the first eruption of the volcano occurred 39 thousand years ago. Some researchers suggest that this is what contributed to the migration of Neanderthals to the eastern part of the Mediterranean Sea. Scientists believe that during that eruption, about 300 cubic kilometers of ash, mixed with large amounts of fluorine, chlorine, and sulfur dioxide, were thrown into the atmosphere.

The volcano began to become particularly active in 1970, when 10,000 local residents were evacuated and never returned to their homes. A few months after the evacuation, the coastal part of the city was completely submerged into the sea to a depth of 10 meters. Thanks to the fact that people heeded the warnings of the authorities in time, they were able to avoid disastrous consequences.

There are no reasons for special concerns yet. People living at the foot of the volcano in Naples need to regularly monitor the research of volcanologists, and in case of a threat, be prepared for urgent evacuation.

The magma underneath has already created the necessary pressure and temperature, after reaching which a powerful eruption could cover the territories of a number of European countries at once.
Researchers from Italy and France have concluded that the supervolcano that rendered a third of Europe temporarily uninhabitable 39,000 years ago is close to another mega-eruption. The exact date cannot yet be given, but the information is significant and indicates the need for close monitoring of this rather dangerous place. The corresponding article was published in Nature Communications (http://www.nature.com/articles/ncomms13712).

Scientists used modeling of processes leading to particularly violent eruptions. Before they happen, magma rising through the earth's crust hits a "lid" at the top. When the threshold pressure is reached, the rocks that make up the “lid” undergo a sharp change. The compounds that make up the magma decompose, releasing the water bound in them. Superheated water vapor immediately begins to heat the surrounding crustal rocks, reducing their strength. After this, the “lid” collapses and the erupting fountain of hot gases scatters debris and ash over a huge distance.

Having modeled how such processes occur in the area of ​​the earth's crust near Naples, where the Phlegrean fields are located, scientists came to the conclusion that now the magma there is close to critical pressure, after which it will trigger the process of avalanche-like destruction of the “lid”. This means that a new eruption here will happen quite soon by geological standards. It is still difficult to specify its timing more precisely, since it is impossible to directly study these processes, and in order to create more accurate models, it is necessary to record more parameters of mega-eruptions of this kind. So far, humanity has encountered only two - 39,000 and 70,000 years ago. And most of their witnesses died from lava spills and ashfall.

39,000 years ago, the volcano that was on the site of the modern Phlegrean Fields had already erupted according to the pattern described above. Then it simply blew up, and now only a slight depression remains in the place of the former huge mountain. Emissions of ash and stones covered an area of ​​more than 1.1 million square kilometers with a thick layer - from Southern Italy to the modern Black Sea region, Donbass and the Caspian Sea. All the way to Romania, the ash layer reached almost a meter. Where vegetation was not completely destroyed, its growth was significantly inhibited.

Volcanic rock particles in the stratosphere greatly scattered sunlight, leading to a string of cold years. The bulk of what was then Europe was already a fairly cool paleotundra. In the absence of even moderate summer warming, the growth of green plant mass stopped, and the lack of light interfered with photosynthesis. Therefore, those animals that did not die during the “rain” from the ashes left a significant territory from Italy to the Urals. The Neanderthals who lived here previously also ceased to be found in this part of the European continent 39,000 years ago. They survived only in Spain, where the ashes did not fall due to the winds.

The Italian supervolcano Phlegrean Fields is one of the most dangerous in the world, not least because more than a million people live around it.

A new study, published in Scientific Reports, has identified the source of the magma that fuels the dormant and ominous cauldron. Unfortunately, this volcano is more dangerous than previously thought.

Search for the supervolcano's hot zone

Typically, scientists use the seismic waves that magma emits as it travels through the crust to determine where it is currently located. But because the supervolcano has remained generally quiet since the mid-1980s, finding its source of magma is much more difficult.

An international team led by specialists from the University of Aberdeen attempted to solve this riddle. Using specialized mathematical analysis of seismic data collected since the mid-1980s, the team identified a hot zone at a depth of 4 km beneath Pozzuoli, near Naples.

According to the study, the hot zone is either a small amount of magma or the molten top of a massive magma chamber whose liquid fire is widespread deep below the earth's surface. Either way, scientists have found compelling evidence of an active heat source that supplies magma to one of the world's most dangerous volcanoes. But the story doesn't end there.

Rising ground level above the caldera

One of the key mysteries of the Phlegrean Fields is their periodic and frightening growth. Between 1982 and 1984, the ground in the crater rose 1.8 meters. Whatever the cause - magma, gas moving through the earth's crust, or the movement of superheated water - the crater soon sank.

New research helps explain why this growth did not end with a volcanic eruption. Seismic imaging shows that the magma's eruption to the surface was prevented by a very rigid, shallow rock formation located above it. This is why the magma spread laterally and was unable to break through.

This means that the risk from the caldera has migrated. "The Phlegrean Fields can now be compared to a pot of boiling soup beneath the surface," says lead author Dr Luca de Siena, a geologist in Aberdeen.

This means that instead of a single eruption point, a new caldera may form.

How were the Phlegrean fields formed?

The Phlegrean Fields remains a monster that scientists understand very poorly. The caldera was formed 40 thousand years ago during one of the most energetic paroxysms of the last few million years. At that time, the supervolcano ejected about 500 cubic kilometers of debris, which could even reach Greenland, despite a distance of 4,600 kilometers.

There have been several eruptions since then, but it has left most of the fireworks to volcanoes located near or within the crater itself, such as Vesuvius and the ominous sulfurous Solfatara. Volcanologists remain acutely aware of the risk to the 6 million people living in the monster's "blast zone" and are therefore constantly monitoring it.

Should we be afraid of a new eruption?

What's really worrying is that the Phlegrean Fields are growing again, although the risk of an eruption is now 24 times lower than in the early 1980s. As always, volcanologists don't know what's really going on, but they believe the volcano is reaching a critical point where an eruption is imminent.

Regardless of whether the eruption results in a new caldera or a regular eruption, de Siena is confident that the volcano is becoming increasingly dangerous.

Forget Yellowstone. Phlegraean Fields is a supervolcano that's really worth worrying about.

Almost all calderas on our planet are potentially dangerous. But if we talk a lot about Taupo or Toba, then Campi Flegrei in Italy for some reason is deprived of attention. In fact, it poses no less a threat than its overseas “brothers”, and can lead to a major catastrophe that will destroy a significant part of Europe. Understanding what is happening to the Italian caldera could be vital in helping to avoid the consequences of its activity in the future.

The last eruption in the subvolcanic system of Campi Flegrei occurred only 477 years ago - in 1538. The amount of volcanic material ejected from the caldera was enough to form the hill of Monte Nuovo near the city of Pozzuoli. Signs of its earlier destructive activity have survived to this day - the fumarole fields of Solfatara with hydrogen sulfide springs and the famous Roman columns of the “Temple of Serapis”, indicating the flooding of the region along the Gulf of Pozzuoli.

Campi Flegrei remains active today, so the National Institute of Geophysics and Volcanology of Italy (INGV) closely monitors its activities. The data obtained over the past few decades is disappointing. From 1982 to 1985, the surface of the caldera rose to a height of about 2 meters in just 3 years. In 1983, the city center of Pozzuoli - Rione Terre - suddenly rose and then fell again. Then about 10 thousand people were forced to leave their homes and were never able to return, since access to this zone is now prohibited.

Since the beginning of 2012, the surface of Campi Flegrei in the Pozzuoli region has been growing by about 6 cm per year. Although these figures are not as impressive as in the 1980s, they raise serious concerns among volcanologists. According to a report from the Vesuvius Observatory published on July 21, 2015, temporary increases in growth occur from time to time in the Phleugrean Fields. For example, in January 2014 alone, the ground rose by 8.5 cm, and in March 2015 - by 3 cm. In total, over the past 4 years, the growth of the caldera surface was 24 cm.

At the end of 2012, severe deformation of the Bocca Grande crater was recorded on the fumarole fields of Solfatara, and over the past few years a large number of tremors have been recorded in the caldera, mainly off the northern shores of the Gulf of Pozzuoli at a depth of 1–4 km. In particular, 119 earthquakes occurred here over the past year. Moreover, since 2003, the temperature of water and steam in the volcano’s fumaroles has risen by 10–15 °C, and the composition of the released gases has become more “magmatic,” that is, with a higher content of carbon dioxide.

What does all of this mean? According to the conclusions of volcanologists, such a situation may indicate, firstly, a further rise of magma, which began in the 1980s. Secondly, this may be due to changes occurring in the hydrothermal system of the volcano. And thirdly, activity may increase due to the appearance of new magma in the bowels of Campi Flegrei. In combination with rising ground, changes in the composition of gases and an increase in temperature in the fumaroles, the latter hypothesis seems the most likely.

Considering that major changes in the 1980s did not lead to an eruption, one can only hope that the current situation will not affect the activity of the volcano. Scientists are still trying to answer the question of when the explosion of Campi Flegrei will occur. This year they drilled into the caldera and installed monitoring instruments at great depths. But for now the future of the Phlegrean Fields remains a mystery.

Science noticed this danger lurking under the feet of humanity only recently - and not a single volcanologist has yet been able to witness its awakening. But they pray to their gods that this does not happen.

Bomb near Naples

The study of the earth's interior using seismic tomography showed that the Naples region rests on a huge magma basin with an area of ​​400 square meters. km. According to volcanologists, this is a real time bomb that may explode someday. However, it is not only the next eruption of Vesuvius that should be feared.

The Phlegrean Fields are by no means harmless monuments of the planet’s geological past. A more detailed study of them showed that this area, covered with several dozen craters, represents the remains of the caldera of an ancient giant volcano, part of which was flooded by the waters of Pozzuoli Bay. Of course, there are examples of other equally impressive huge calderas in the world. For example, the island of Thira, the “bagel” of which is all that remains after the explosion in the 15th century BC. volcano Santorini. But research into the volcanic region of Naples continues, and who knows what discoveries they will bring.

What if the Phlegrean Fields and Vesuvius are not two separate volcanoes (ancient and modern), but two “exhaust pipes” of an older and much grander volcano, the caldera of which is the Bay of Naples? Of course, such an assumption can only be called science fiction for now, but who knows!

However, let us return to an equally interesting scientific reality - to the Phlegrean Fields. So, their study showed that they represent a huge ancient volcano, now dormant - but with a slightly different design than, for example, its neighbor Vesuvius. This type of volcano received the working name supervolcanoes (supervolcano) - primarily for its size.

Fiery plagues of the Earth

A typical volcano, as we imagine it, is a cone-shaped hill with a crater from which lava, ash and gases erupt. It is formed like this: in the depths there is a volcanic chamber with magma, the contents of which find their way (channel) through cracks, faults and other “defects” of the earth’s crust. As the magma rises, it releases gases, becoming volcanic lava, and flows out through the top of a channel, commonly called a vent. Breaking off around the vent, the products of the eruption build up the cone of the volcano.

Supervolcanoes have their own peculiarity, because of which until recently no one even suspected their existence. The fact is that they are not at all similar to the cone-shaped “caps” with a vent inside that are familiar to us. And it’s unlikely that they would be able to build something similar - and not only because such a mountain would reach several tens of kilometers at the base and 15-20 in height, it would simply begin to fall underground, due to the fact that the crust is not able to withstand such a weight. Actually, this is approximately what happened.

Their sources are located much closer to the surface of the earth and represent huge magma reservoirs - their horizontal cross-sectional area is correspondingly large. According to one version, the eruption of a supervolcano began with magma melting and breaking the layer of the earth’s crust above it, protruding a huge hump on the earth’s surface (several hundred meters high and 15–20 or more kilometers in diameter).

Then the pressure increases, the magma looks for a way out. Numerous vents and cracks appear along the perimeter of the supervolcano - and then its entire central part collapses down into the fiery underworld. The collapsed rocks, like a piston, abruptly release huge volumes of magma and gases from the depths - and they are thrown into the sky in giant fountains of lava and cyclopean clouds of ash.

Such a phenomenon has never been seen before not only by volcanologists, but also by homines sapientes in general - all earthly supervolcanoes erupted long before their appearance. However, the question remains: have they always been a rare geological phenomenon, or once upon a time in the era of the stormy geological youth of our planet, their eruptions shook its body relatively often? Is their occurrence related to periods of the so-called. “increased volcanic activity” of the planet? The answers to these questions have yet to be found.

When the eruption of the supervolcano ended, what was left was a huge caldera, inside of which a huge valley was formed - a kind of “lid” over the magma chamber. The Phlegrean Fields could be part of such a “lid”, its edge. Thus, if a classic volcano can be compared to a “pimple,” then a supervolcano is more like a serious hematoma or abscess.

His further fate may be different. It can sleep peacefully, turning into a reservoir for a lake, can become a hot valley of thermal springs, and can sometimes play pranks with small eruptions, becoming covered with volcanic cones. But it may erupt again - shaking the earth's crust. Everything depends on the processes occurring in its depths.

Today, several objects fall under the definition of “supervolcano”. Firstly, these are the same Phlegrean Fields. Second is the Toba volcano on the island of Sumatra, which last erupted about 74,000 years ago. Now its giant caldera has an area of ​​1775 square meters. km is filled with water and is a very picturesque lake.

An ancient and very large supervolcano was recently discovered in Kamchatka. While exploring the area of ​​the Bath Springs, employees discovered the remains of an ancient caldera there. A more thorough study revealed its dimensions (25 by 15 km) and its approximate age - about one and a half million years. Thus, it is several times older than most of the Kamchatka volcanoes. Scientists were led to the version that the caldera is an ancient supervolcano by studying the dome-shaped uplift in its center - caused by the presence of a powerful magma chamber underneath.

But the most famous supervolcano is Yellowstone National Park, located in the Rocky Mountains in the northwestern part of Wyoming (USA). The most thoroughly studied, it also became the protagonist of the documentary film “Supervolcano” (produced by the BBC) and the fictional thriller of the same name - presenting its possible eruption as the beginning of a grandiose cataclysm.

Volcanic winter

The eruption of an ordinary volcano on a planetary scale is nothing more than a terrible sight. What is shown in the Hollywood films “Dante’s Peak” and “Volcano” is nonsense compared to what will happen when a supervolcano erupts. In a matter of hours, tens or even hundreds of cubic kilometers of ash and lava will be thrown out. And it will not be possible to defeat the elements with the help of bulldozers and dynamite - humanity can only watch and wait. “Supervolcano” conveys such a sad moral to the audience.

Detailed studies of Yellowstone Park, famous primarily for its geysers, began in the mid-twentieth century. Even then, scientists came to the conclusion that its giant caldera (70 by 30 km) was clearly of volcanic origin. Of course, the mind refused to believe in the existence of volcanoes of such size - so it took many more years of research and theoretical development before a model of a supervolcano was developed.

During them, it became known that the last three eruptions of the Yellowstone supervolcano occurred two million years ago, one million three hundred thousand years ago and six hundred thirty thousand years ago. Thus, the conclusion suggested itself that the eruptions are more or less periodic, and the period is about six hundred and fifty thousand years. This means that the next eruption will only have to wait a little - of course, according to the geological clock. However, not everyone heard this clarification and a sensation swept across the United States, picked up in other countries and then embodied on the screen: the Yellowstone supervolcano will soon explode, save yourself!

Forecasting the consequences of global cataclysms is not only interesting, but also very popular. These forecasts are very popular among millions of ordinary people who read and contemplate the scenario of the coming “end of the world.” Therefore, as soon as forecasts appeared regarding the date of supervolcano eruptions, forecasts of their consequences did not slow down.

So, in the first minutes after the collapse into the sky, columns of hot gases and ash will shoot up to a height of up to fifty kilometers. At the same time, pyroclastic flows will rush along the surface of the earth, burning everything within a radius of several tens of kilometers. And if the Yellowstone area is relatively sparsely populated, then such an explosion of the Phlegrean Fields would incinerate an area inhabited by millions of people.

In a few hours, most of the ejected ash will begin to settle, covering entire states with it. Cities located hundreds of kilometers from Yellowstone, of course, will not suffer the fate of Pompeii, but traffic will be very difficult - if not impossible. In addition, volcanic ash is not snow, it will not melt in the spring, and when it falls, it clogs the respiratory organs of people and animals, and disables machines and mechanisms. It will also be difficult to breathe due to volcanic gases, which include sulfur compounds.

But the ash remaining in the atmosphere will pose a much greater danger: by blocking the sun’s rays, it can create the effect of a “volcanic winter”, almost no different from the “nuclear winter” - an effect that arises during a global nuclear conflict and was calculated for the first time twenty years ago by the Soviet Union. mathematician Nikita Nikolaevich Moiseev. It is now believed that the eruption of Mount Tambora (1815), which released several cubic kilometers of volcanic material into the atmosphere, caused a cooling on a planetary scale - leading to a “year without a summer” in Europe. Because of this eruption, the last pan-European famine in history occurred in 1816. Tens of thousands of Germans then moved to Russia and the USA. But these are just flowers. Recent studies have shown that the eruption of the Toba supervolcano led to a drop in average temperatures by eleven degrees, and the resulting glaciation had the most catastrophic consequences.

As you might guess, such a catastrophe is akin to a nuclear war or the fall of an asteroid. However, humanity can avoid war if it is guided by reason and not by emotions. You can try to shoot down or deflect an uninvited space “aliens” using existing technologies. But methods for preventing the eruption of not only “super-”, but also ordinary volcanoes do not yet exist - which is why these forecasts are, to put it mildly, cause concern.

On the other hand, there is no reason to panic either. The described catastrophe can happen - but not tomorrow or in a year. But a new reason to expect the “end of the world” has appeared in the near future. Therefore, we will still hear new “sensations” about the imminent explosion of a supervolcano, as well as about the collision of our planet with an asteroid, a black hole, and perhaps even with