Last midnight, a strong earthquake of magnitude 5,9 It shook southern Italy with its epicenter in the Tyrrhenian Sea, off the coast of Italy. Gulf of Naples and the island of CapriThe tremor, recorded at 00:03 local time, immediately activated infrastructure control protocols and generated concern among the population, although no damage or casualties have been reported.
According to the first official data from National Institute of Geophysics and Volcanology of Italy (INGV)The event occurred at an extraordinarily high depth, around 414 kilometers below the surfaceThis characteristic, unusual for this area, explains why the earthquake was felt widely but, at the same time, had less destructive capacity in inhabited areas.
Epicenter in the Tyrrhenian Sea and extent of the tremor
The earthquake originated in the Tyrrhenian Sea, off the coast of Campaniavery close to the Gulf of Naples. Initial calculations place the epicenter at about 10 kilometers from the Capri island already about 8 kilometers from the town of Anacapri, in the heart of the Mediterranean tourist area.
According to the information released by the INGV Seismic Room in RomeThe earthquake was detected quickly and located at a point well below the areas where most Italian seismic movements usually originate, which tend to be concentrated in the upper crust.
The seismic wave propagated across much of the country. The tremor was felt in Naples and its metropolitan area, In Sorrento Peninsula and Amalfi Coast, as well as along sections of the Tyrrhenian coast of CalabriaConversely, reports also came in from the coasts of Lazio, Toscana and even Liguriawhich gives an idea of ​​the geographical scope of the phenomenon.
Despite that wide range of perception, No material or personal damage was reportedCivil Protection authorities in Campania confirmed that no reports of landslides or injuries were received overnight in the towns closest to the epicenter, including Capri and Anacapri.
A "phantom earthquake" for the residents of Capri
The enormous depth of the event has led some local officials to describe it almost as "phantom earthquake"The mayor of Anacapri himself explained to Italian media that, on the island, no one clearly felt the tremor and that Many residents learned about the earthquake when they woke up and read the news in the press and on social media.
This contrast between the relatively high magnitude (5,9) and the low local perception is due to a physical effect well known to seismologists: The great depth attenuates the intensity of the ground movement near the surface, thus reducing the potential for damage to buildings and infrastructure.
Even so, in cities like Naples, Salerno, or various locations in southern and central Italy Some people reported noticing a slight swaying of lamps, the vibration of glass, or a brief feeling of dizziness. However, there were no reports of widespread panic or mass evacuations.
Delays and checks on the Italian rail network
One of the most visible effects of the earthquake occurred in the rail transport in southern ItalyFollowing safety protocols, the Italian Railway Network (RFI) decided reduce the speed of trains at the Naples node to allow for detailed inspection of roads, bridges and other infrastructure.
That preventative decision led to considerable delays in long and medium distance servicesThe trains that left for the north from Salerno and Naples Central Station Delays reached up to 100 minutes. Rome TerminiAt the main station of the Italian capital, changes to schedules, occasional cancellations and delays of up to 140 minutes were announced for trains heading south.
After completing checks throughout the night, RFI technicians reported that No structural damage had been detected on the network. From that moment on, rail traffic began to gradually return to normal, with the expectation of absorbing all delays throughout the day.
From Civil Protection of Campania It was emphasized that the activation of these automatic protocols is part of the prevention strategy against earthquakes of a certain magnitude, even when, as in this case, the depth of the hypocenter already pointed to a relatively low risk to infrastructure.
A rare seismic phenomenon off the coast of Campania
According to experts at the INGV, the earthquake recorded off the Gulf of Naples constitutes an episode "quite rare" for this geographical areaThe unique aspect of the event lies in the fact that The hypocenter was located well below the usual seismogenic zones from Italy, moving away from the typical pattern of shallower earthquakes.
Most earthquakes that affect Italian territory originate in the upper crust of the EarthEarthquakes typically occur at depths ranging from a few to several tens of kilometers. In contrast, last night's earthquake struck at a depth of over 400 kilometers, in an internal region of the planet where different geological mechanisms are at work.
The INGV has explained that these types of deep events are related to the presence, in the Earth's mantle, of a "slab" of oceanic lithosphere in the process of subductionThat is, a fragment of tectonic plate that has been sinking beneath the Tyrrhenian Sea for millions of years. This phenomenon generates a particular type of seismicity, frequent off the coast of Calabria and Sicilybut much less common off the coast of Campania.
In the last 40 years, the following have been recorded several significant deep earthquakes in the southern Tyrrhenian Sea, with magnitudes close to or slightly below 6Among them, the following events stand out: 28th October 2016 (magnitude 5,8 at a depth of 481 km), the one of 29th October 2006 (magnitude 5,8 at 221 km) and the one of November 3th 2010 (magnitude 5,4 at 506 km). More recently, on the night of October 26-27, 2023, a deep earthquake of magnitude 4,2 was recorded off the Sorrentine Peninsula.
Historical background in the Tyrrhenian Sea and the Gulf of Naples
The magnitude 5,9 earthquake off the Gulf of Naples is part of a long historical series of deep earthquakes in the Tyrrhenian Seasome of them of notable intensity. The INGV itself recalls that the closest precedent in this area dates back to December 27th 1978, when an earthquake of magnitude 5,9 was also recorded at a depth of about 392 kilometers, off the coast of the town of Gaeta.
Even more striking is the case of a great deep earthquake occurred in 1938 in the Tyrrhenian Sea, described in scientific literature with an estimated magnitude of between 6,8 and 7,1. It is one of the most powerful seismic events in the Italian historical catalogHowever, again, the depth of the fire mitigated its destructive capacity on the surface.
These examples illustrate how, in the Mediterranean context, Not all large earthquakes result in catastrophes on land.The depth of the hypocenter, the type of rock through which the waves pass, and the distance to inhabited areas play a key role in determining the actual impact of each event.
This time, the earthquake occurred around the area of ​​the Phlegraean Fields, a large, active volcanic caldera located west of Naples and considered one of the most dangerous in Europe. However, the INGV has been emphatic in stating that There is no direct relationship between deep earthquakes and volcanic or bradyseismic phenomena. that periodically affect that area.
Why did almost no one feel it despite its magnitude?
One of the most frequently asked questions in both Italy and the rest of Europe has been Why was an earthquake of almost magnitude 6 barely felt? in the area where it originated. The answer lies in the combination of extreme depth and the propagation of seismic waves through the mantle.
In practical terms, an earthquake of magnitude 5,9 at a depth of more than 400 kilometers generates ground movement that, on the surface, usually translates into slight vibrations and moderate oscillationsmuch lower than those that would be produced by an earthquake of similar magnitude with a focus located 10 or 15 kilometers deep.
Specialists from the INGV and other geological services explain that the deeper the hypocenter, The greater the distance that seismic waves travel until it reaches populated areas. Along this path, the energy disperses and attenuates, reducing ground acceleration and, therefore, the potential for damage.
Paradoxically, that same depth contributes to the possibility that the earthquake can felt hundreds of kilometers from the epicenter with a low but noticeable intensity. Hence, warnings have been received from regions as far away as Rome, Ancona, Florence, Bologna, Padua, Trento, Milan or La Speziawhile in Capri or Naples many people didn't even realize what had happened.
Institutional response and coordination in Campania
Following the earthquake, Italian authorities quickly activated the emergency coordination mechanismsIn Naples, the Relief Coordination Center met, convened by the Prefecture, with the participation of officials from the INGV, regional Civil Protection, mayors of coastal and island municipalities, police forces, Coast Guard, health services, representatives of the Metropolitan City and other key agencies.
During the meeting it was confirmed that the earthquake, having occurred at about 414 kilometers deep, it had not generated effects capable of causing damage Neither in the towns nor in the coastal areas. The mayors of the coastal municipalities and the islands of the Gulf of Naples confirmed the absence of damage to public buildings, homes, or critical infrastructure.
Even so, the Prefecture stressed that it will maintain constant monitoring of the situation, especially regarding possible landslides on stretches of coast and cliffs, tasks for which the Port Authority continues to carry out inspection work along the coastline.
Meanwhile, several local councils in the area have taken the opportunity to update their Municipal Civil Protection Plansincorporating or revising sections related to tsunami risk and evacuation procedures in case of seismic or volcanic emergency.
A reminder of seismic risk in southern Europe
Although the magnitude 5,9 earthquake in the Gulf of Naples has not caused any damage, Its symbolic and technical impact is relevant. for Italy and for southern Europe as a whole. The episode once again highlights that the country sits on a complex tectonic environment, where converge active faults, subduction zones, and high-risk volcanic areas.
Data from the INGV shows that, in the last year alone, [number] have been registered in Italy thousands of earthquakes of varying magnitudeWith an average of about 43 events per day, roughly one every 33 minutes. Most are low intensity and go unnoticed, but a small percentage reach magnitudes that can be felt by the population.
In 2025, they were counted in the Italian region and nearby seas 21 earthquakes with a magnitude between 4,0 and 4,916 of them in national territory or adjacent waters. None exceeded that magnitude, which reinforces the idea that Episodes like the 5,9 in the Gulf of Naples are rarebut not extraordinary within the long-term dynamics of the central Mediterranean.
For countries like Spain or other states in the Mediterranean region, this type of event serves as reminder of the need to continue investing in seismic monitoring, updating of building regulations and emergency plans coordinated at European level, especially in densely populated areas with significant historical heritage.
In the end, the deep earthquake under the Gulf of Naples has functioned almost as a real-time simulation of alert and response systems: a stark warning of the activity hidden beneath the Tyrrhenian Sea, but with a fortunate outcome as it caused no damage, allowing us to calmly analyze what is being done well and in what aspects there is still room to strengthen prevention and resilience against future earthquakes.
