A Rare Supervolcano Beneath Italy Shows Signs of Pressure Build-Up Near Naples’ Crowded Streets

Part of the story of Pozzuoli, a seaside town, is told by the harbor. Old stone docks with slightly off angles and cracked edges sit strangely above the waterline. Residents occasionally look down at the ground beneath their feet and sense something that isn’t visible but is unquestionably there, even though fishing boats continue to come and go.

Since 2005, the elevation of the land has increased by over 1.6 meters. Even though it doesn’t sound dramatic, it’s enough to alter coastlines, destroy structures, and undermine trust. Scientists refer to this slow breathing of the Earth as bradyseism. As you watch it happen, you get the impression that the ground is subtly pushing its boundaries.

West of Naples, beneath this area is Campi Flegrei, a huge volcanic caldera that encases towns, highways, and residential areas. Unlike the neighboring Vesuvius, it is not a mountain. It’s more subdued, concealed, and flatter. However, it can also cause much more harm, which is maybe why it attracts such close attention.

The number of earthquakes has increased recently.

Since 2022, there have been over 54,000 small earthquakes recorded, many of which are too weak to inflict damage but powerful enough to alert locals to changes beneath the surface. Windows tremble. Shelves shake. Dogs bark for no apparent reason. Though fleeting, these moments are remembered.

At least not yet, scientists think the pressure isn’t coming directly from rising magma.

Instead, a geothermal reservoir beneath the surface is accumulating hot fluids and gases. The ground is forced upward and the surrounding rock is cracked when this pressure rises. Whether this process will release itself gradually or abruptly is still unknown.

Sulfur fumes rise in twisted white plumes in places like the Solfatara crater, where steam escapes. The air has a heavy, metallic smell. It’s difficult to ignore the heat that is active but invisible beneath you as you stand there.

The yellow alert level, which indicates caution but not panic, has been maintained by authorities.

That difference is important. Experts stress that there is no immediate threat of a catastrophic eruption. Nonetheless, some scientists claim that the crust is being pushed closer to its limit. Phreatic eruptions, which are small explosions caused by steam, are still possible.

This has happened in Italy before.

Within a week, the ground near Pozzuoli erupted in 1538, forming a brand-new hill called Monte Nuovo. Even though the speed of that change seems unthinkable now, it took place here, where people now go grocery shopping and take their dogs for walks.

Over a million people currently reside in the high-risk area.

Civil protection authorities have meticulously mapped out evacuation plans. There are designated roads. They practice procedures. Planning for something uncertain, however, seems to come with its own set of challenges.

Life goes on as usual.

Cafés are still full. Kids go to school on foot. When tourists visit the neighboring Mount Vesuvius, they frequently don’t realize that there is another volcanic system beneath them. It’s possible that fear has been tempered by familiarity, making the extraordinary ordinary.

Seismic patterns, ground movement, and gas emissions are continuously observed by scientists.

Monitoring carbon dioxide levels, the Italian National Institute of Geophysics and Volcanology looks for indications that magma may start to rise. Evidence to date points to hydrothermal pressure rather than magma intrusion as the cause of the current unrest.

There is some comfort in that distinction.

However, there is still uncertainty.

The timescales of supervolcano systems are much longer than those of human life. Pressure may increase gradually, decrease gradually, or fluctuate suddenly. One gets the impression that something ancient is moving at its own speed as they watch the ground rise centimeter by centimeter.

This place has always had life on it.

Whether it’s just a shift or a prelude to something more is the question.