From 16:53 of 15 February 2025, i Campi Flegrei they are affected by one seismic swarm which, as of February 17, recorded 282 earthquakes of various intensity, with a maximum magnitude of 3.9. The area is going through a phase of intensification of the bradyseisma phenomenon already observed in the past. On May 20, 2024, another swarm had recorded magnitude events up to 4.4. The INGV (National Institute of Geophysics and Volcanology) stresses that the presence of earthquakes with magnitude greater than 3.0 It does not constitute an anomaly in contexts of particularly intense seismic swarms.
No anomaly in addition to seismicity
According to multiparametric monitoring, all parameters, with the exception of seismicity, Following regular increases without significant anomalies. Soil lifting continues with an average of About 10 millimeters per monthwhile the flow of the main fumaroles returned to the values of two weeks ago, after a slight drop. Also The concentrations of gas emitted do not present significant variations.
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Campi Campi: the most active volcanic area of Campania
Unlike the Vesuvius and of Ischiai Campi Flegrei are currently the only volcanic area of Campania with an evident dynamic. Bradisism, resumed since 2005, led to the rise in the level of “yellow” alert since 2012. The earthquakes, concentrated in the first 3 kilometers of depth, are even unacceptable at low magnitude. Since 2005, around 23,000 earthquakes have been recorded, many of which are grouped into shamans. However, The communication relating to shaman has aroused perplexity in citizenship.
What are seismic swarms?
Seismic swarms are sequences of earthquakes in a limited area and in a certain period of time. Unlike seismic sequences, they do not have a predominant event and are typical of volcanic areas, often associated with the ascent of fluids or magma.
How are seismic swarms defined and communicated to the Flegrei fields?
The INGV uses two criteria to identify a swarm at the Flegrei fields:
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Scenario 1: at least 3 events with magnitude ≥ 1.0 in an hour.
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Scenario 2: at least 10 events with magnitude ≥ 0.0 in an hour.
The communication protocol provides:
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Preliminary press release: emitted within 5 minutes from exceeding a threshold.
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Regular updates Every 30 minutes, 3 hours or 6 hours.
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“End of swarm” press release: published after 3 hours from the last significant event.
What does the end of a swarm mean?
The end of a swarm does not imply the cessation of seismic activity, but only the conclusion of a close sequence of events. Seismicity can continue with sporadic shocks and a new swarm could occur.
The most intense swarm of the bradyseismic crisis
The most significant recent swarm occurred between 20 and 21 May 2024, with 443 registered earthquakes, 5 of which with a magnitude greater than 3.0 and a maximum of 4.4.
