Last midnight, a magnitude 5,9 earthquake stirred the waters of the Tyrrhenian Sea in front of gulf of naplesThe earthquake, which struck at 00:03 Italian time on March 10, occurred in an area very close to the island of Capri. It immediately activated seismic monitoring and civil protection systems, but caused no damage or injuries.
What has most caught the attention of seismologists is that the hypocenter was located a exceptional depth, around 414 kilometersThis is well below the layers where most Italian earthquakes occur. This characteristic, unusual for this area, explains why the tremor had a very limited impact on the surface, despite the recorded magnitude.
Epicenter off Capri and perception of the tremor
According to data from National Institute of Geophysics and Volcanology of Italy (INGV)The epicenter of the earthquake was located at sea, about 10 kilometers from the island of Capri and very close to the municipality of Anacapriwhich is located approximately 8 kilometers from the calculated point. The initial location was determined by the INGV Seismic Room in Rome a few minutes after the event.
Initially, automated records indicated that the tremor could be felt in various areas of southern Italy, from the area of Nápoles and the Sorrento peninsula as far as the Amalfi Coastextending south along the Tyrrhenian coasts of Calabria and, in the opposite direction, towards the regions of Lazio, Tuscany and even LiguriaHowever, the detailed INGV report clarifies that, due to the enormous depth, most of the population barely perceived the movement or did not notice it at all.
In towns as close to the epicenter as Capri and Anacapri No significant reports have been received from citizens who felt the earthquake. In the city of Naples itself and in its province, authorities are speaking of a very weak or non-existent tremor for most residents, far from what would be expected of an earthquake of similar magnitude but shallow.
This contrast between the numerical magnitude and the low perception is due, according to experts, to the fact that the Seismic waves are strongly attenuated when traveling from such great depthsUpon reaching the surface, the released energy is much more spread out and the ground acceleration is much lower than that which would be caused by a shallow event.
No personal or material damage, but with significant train delays
La great depth of the hypocenter This has been crucial in ensuring that, despite the 5,9 magnitude earthquake, no significant damage was recorded. Both the INGV (National Institute of Geophysics and Volcanology), the Prefecture of Naples, and the mayors of the coastal and island municipalities have confirmed that There are no reports of damage to buildings or injuries. linked to this episode.
Even so, out of sheer caution, the shock has had consequences in the transport infrastructureThe Italian Railway Network (RFI) immediately activated safety protocols, slowing train traffic at the Naples hub to allow for the inspection of tracks and associated structures.
This preventative speed reduction generated significant delays on several rail corridorsThe convoys that were traveling north from Salerno and Naples Central Station experienced delays of up to 100 minutes. At the station of Rome Termini Schedule changes, cancellations and waits of up to 140 minutes were recorded on trains heading south.
Once the technical checks were completed, the railway authorities reported that No structural damage had been detected on the network. According to RFI, traffic has gradually returned to normal throughout the morning, although many users have suffered the consequences of a particularly difficult start to the day.
Also from the Port Authority The coastline has been monitored to rule out any potential landslides on cliffs or incidents in sensitive coastal areas. The prefecture has indicated that, so far, No significant changes have been observed on the coastline attributable to the earthquake.
A deep and rare earthquake in the southern Tyrrhenian Sea
The INGV has emphasized that this seismic event is “quite rare for this geographical area”Most Italian earthquakes originate in the upper bark, at depths of a few kilometers to several tens, while this morning's earthquake occurred at more than 400 kilometers, well below the usual seismogenic zones.
Seismologists link these types of movements to the presence, in the Earth's mantle, of a “slab” of oceanic lithosphere (slab) that has been sinking beneath the Tyrrhenian Sea for millions of years. This subduction process generates seismicity at great depths, which is usually more frequent off the coasts of Calabria and Sicily, and less common off the coast of Campania, where the current earthquake occurred.
However, this is not the first time that the southern Tyrrhenian Sea has recorded deep earthquakes of moderate or high magnitudeOver the past 40 years, the region has experienced similar episodes, such as that of 28th October 2016, with a magnitude of 5,8 at a depth of 481 km, or the one of 29th October 2006, also with a magnitude of 5,8 but at 221 km. On November 3, 2010, another deep earthquake of magnitude 5,4 occurred at about 506 km.
More recently, between the night of October 26 and 27, 2023, a deep earthquake of magnitude 4,2 was recorded off the coast of Sorrento Peninsulain the province of Naples. Although of lesser intensity, specialists already drew attention to this category of events, far from the surface but capable of making themselves widely known when the magnitude increases.
According to the historical catalog, the Strongest documented deep earthquake in this area dates back to December 27th 1978, when a magnitude 5,9 earthquake originated at a depth of 392 km off the coast of GaetaEven further back, a 1951 study describes a powerful earthquake that occurred in the Tyrrhenian Sea in 1938, with an estimated magnitude of between 6,8 and 7,1, considered one of the most energetic earthquakes in the historical record in this region.
Coordination and review meeting of civil protection plans
As a result of the earthquake, the Prefecture of Naples This morning, a meeting of the Relief Coordination Center was convened to analyze the situation and coordinate a possible response. The director of the INGV participated in the meeting. Lucia Pappalardo, the regional director of Civil Protection, Italo Giulivo, as well as mayors of coastal and island municipalities, representatives of the Metropolitan City, police forces, Coast Guard, health authorities (AA.SS.LL.), RFI, Italian Red Cross and the Regional School Office.
During the meeting, INGV explained that the The earthquake originated at a depth of 414 km. due to causes completely independent of the volcanic and bradyseismic phenomena of the area Campi FlegreiIn other words, there is no direct relationship between this deep event and the volcanic activity that is causing concern in the area around Naples, where episodes of ground deformation and seismicity associated with the caldera are closely monitored.
Local authorities confirmed that, following initial inspections, No damage to people or property has been detectedNevertheless, the experience serves as a reminder and has prompted coastal and island municipalities to accelerate the update of their Municipal Civil Protection Plans, with special attention to tsunami risk already the evacuation procedures in case of emergency.
In addition, the Coast Guard continues with surveillance tasks along the entire coastline to rule out minor landslides or cliff problems that might have gone unnoticed initially. The Prefecture has indicated that the situation is under constant observation, although no significant consequences are expected from this particular earthquake.
The institutional response has also been interpreted as a kind of “real-time exercise” of the emergency mechanisms, useful to measure the coordination between administrations, the speed of communication with citizens and the ability to review protocols in a region with a high level of geological risk.
Seismic and volcanic context of Naples and southern Italy
The Naples metropolitan area, with almost 3 million inhabitants and a key economic force for southern Europe, it sits on a geological environment where active faults, volcanoes and deep structures such as the subducting lithosphere beneath the Tyrrhenian Sea. The coexistence of these dynamics makes the region one of the most seismically and volcanically complex areas on the continent.
In recent years, media and scientific attention has focused particularly on the caldera of Campi Flegrei, west of Naples, where a sustained increase in seismicity and ground deformationEpisodes of ground heaving, swarms of microseisms And tremors of magnitude greater than 4 have forced the reinforcement of emergency plans, with preventive evacuations and temporary closures of buildings at different times.
In contrast to this surface seismicity linked to volcanic processes, the deep earthquake in the Gulf of Naples It belongs to a different tectonic family. Its origin is associated with the subduction of an ancient oceanic plate beneath the mantle, far from the shallow areas that are of greatest concern due to their destructive potential. However, the overlap of multiple sources of geological hazard It forces authorities to consider very diverse scenarios in their planning.
From the perspective of risk management in Europe, this episode confirms that It is not enough to monitor only one type of threatPrevention policies must integrate information from seismic networks, volcanic observatories, geological studies and vulnerability analysis of built heritage, both in Italy and in other Mediterranean countries with similar characteristics.
The experience of other major earthquakes in Italy, such as the one in L'Aquila in 2009 or the Irpinia in 1980, has shown that the true impact of a large-magnitude earthquake is measured not only in casualties and damaged buildings, but also in the economic and social resilience of the affected regions. In densely populated areas with an aging housing stock, any improvement in prevention can make a significant difference.
Old housing and seismic regulations: the long-term challenge
One of the major challenges for southern Italy, and particularly for the area around Naples, is the age of the building stockIn the province of Naples, a very significant part of the housing was built before the entry into force of the most demanding anti-seismic regulations, promoted after the great earthquakes of the second half of the 20th century.
Although in recent years the Italian Government has implemented structural reinforcement programs Despite significant subsidies for the rehabilitation of vulnerable buildings, experts warn that the process is progressing slowly. Among the difficulties they cite are the lack of technical resources in some municipalities, the bureaucratic complexity of the projects, and the time required to work on a dense urban fabric, often protected for its historical value.
The tremor recorded in the gulf of naplesDespite not having caused any damage, it is interpreted as a relatively benign warning about what might happen if an earthquake of similar magnitude occurred at a shallow depth beneath densely populated areas. The contrast between this deep event and the most critical scenarios helps illustrate the importance of investing in prevention before a truly dangerous event occurs.
In the European context, where several historic cities are located in seismic areas, the Italian experience is considered a key laboratory to develop adaptation strategies, infrastructure reinforcement, and urban planning based on seismic safety criteria. Coordination between government bodies, transparency in the use of funds, and citizen involvement are central to the debate.
The magnitude 5,9 earthquake in the Gulf of Naples has demonstrated how a A profound event can shake up agendas Political, technical, and social measures were implemented without causing visible damage. The combination of scientific monitoring, preventative response in transportation, coordination meetings, and review of emergency plans leaves a clear impression: southern Italy remains an area of significant seismic and volcanic risk, but each episode like this offers an opportunity to adjust protocols and reinforce a culture of prevention that, in the long run, can make all the difference when the next major earthquake strikes.
