According to the National Institute of Geophysics and Volcanology (INGV), the 4.0 magnitude Richter earthquake occurred on Monday, at 10:08 pm, at a depth of around three kilometers, between the cities of Naples and Pozzuoli. No one was injured and no buildings were damaged. However, according to Italian civil protection, panic has spread among the local population.
Another magnitude 3.2 earthquake occurred at 6:30 a.m. Tuesday. The region was hit by a 4.2 magnitude earthquake on Wednesday. It was the strongest earthquake in the region in 40 years and also paralyzed public transport. Schools remained closed, buildings, roads and bridges were closed.
On a powder keg
The Phlegrean Fields extend over an area 16 kilometers in diameter west of Vesuvius and exhibit high volcanic activity. They were created by a very large eruption 39,000 years ago, which left a giant crater measuring around 100 square kilometers – two-thirds of which were on the sea floor. The term “Phlegrean” comes from ancient Greek and means “burning”.
In Naples, people know very well that they are sitting on a powder keg. The area has been on yellow alert for eleven years, which requires caution. “The population’s fear is enormous. “They are afraid of earthquakes, but many residents believe that the volcano’s eruption is impossible and simply tune out this idea,” said Giuseppe Di Natale, who has studied volcanoes and “bradyism” (the rise and fall of the Earth) for 40 years. years) carries out research in this volcanic area.
Thousands of smaller earthquakes
Thousands of small earthquakes have been recorded in the area in recent months, an average of about 40 per day. Most of them are barely noticeable. Most of the time there are barely noticeable vibrations that only seismographs record, but there are also shocks that sometimes cause plaster to fall off walls and scare people.
“In the Phlegrean Fields, seismicity has never been so high, while the real problem is that the current tremors may already be the harbingers of the eruption, which could be a super-eruption,” said volcanologist Giuseppe Mastrolorenzo.
Getty Images/Angelafoto A supervolcano lies dormant beneath countless hot springs and gas leaks
The floor rises and falls
“Increasing ground elevation indicates increasing internal pressure beneath the earth, which also leads to increasingly strong and frequent earthquakes. It is clear that if this pressure continues to increase, sooner or later the rocks on the surface will no longer be able to support it, so an eruption will occur. Unfortunately, at the moment we don’t know the resistance limit of the rocks in the first three kilometers deep, so we have no idea how high the risk of an eruption could be,” said Di Natale.
Research attributes the rise and fall of the Phlegrean fields to underground movements of magma. When magma rises from the deepest layers of the Earth’s interior below Pozzuoli, 15 kilometers from Naples, the entire area begins to rise. As soon as the magma sinks again, the bulging at the Earth’s surface decreases – and the Phlegrean fields also sink again.
In 1983, there was great excitement in Pozzuoli when the land rose again by more than a meter. The new situation lasted several months. It was accompanied by earthquakes that caused significant damage to the masonry of the old houses in the port area. More than 30,000 people had to abandon their homes for several weeks until the land calmed down again.
Getty Images/iStockphoto/Giovanni Russo An eruption would have far-reaching consequences for the area near Naples
“Extremely dangerous condition”
“Today the ground level is higher than it has ever been in recent centuries. This means that the internal pressure is stronger than it has been since the last volcanic eruption in 1538”, warned Di Natale. Experts do not exclude that the new rise will reach a point where the rock layers will no longer be able to withstand the forces of expansion, as a new study confirmed in June.
The volcano is in “extremely dangerous” conditions, said study co-author Stefano Carlino. It is important that you are prepared for all eventualities. Exactly how devastating the effects of an outbreak could be today is not completely clear. An INGV simulation from 2011 shows the force that could come from the supervolcano.
Outdated evacuation plans
Civil Defense is working on a major evacuation plan for the densely populated region. This is urgently needed because evacuation tests have not been repeated for years. There is also a lack of a map showing buildings at risk from earthquakes, Italian newspaper La Repubblica reported.
In the most extreme case, 1.3 million people across the Naples region must be taken to safety within 72 hours. The evacuation would be coordinated by the army and civil defense. In three days, an entire region was to leave the region by train, bus and car. However, an eruption would also have consequences that go far beyond the immediate area of influence. The eruption about 39,000 years ago released such a large amount of ash into the atmosphere that it influenced the climate around the world.
However, INGV director Francesca Bianco reassured: “None of the data suggests that this is a precursor to an imminent eruption.” The Phlegrean Fields and Vesuvius have become “the best monitored volcanoes in the world”.