Campi Flegrei

[bjdeming]

[INGVvulcani on X: "CAMPI FLEGREI - FINE SCIAME Si è concluso lo sciame sismico ai #CampiFlegrei iniziato alle ore 8:38 (ora locale) del 12/05/2024 e costituito in via preliminare da 19 terremoti con magnitudo Md≥0.0 e magnitudo max Md=1.7±0.3. Info banca dati Gossip https://t.co/9QQWocM6AA https://t.co/Pvk7chTCvv" /

 

[bjdeming]

Everything is okay, but given the recent swarms, here is their weekly bulletin (PDF machine-translated text below -- see bulletin for graphics):

[INGVvulcani on X: "Sul sito dell'INGV Osservatorio Vesuviano è stato pubblicato il bollettino settimanale (6 maggio - 12 maggio 2024) di sorveglianza vulcanica dei Campi Flegrei. Il documento si trova al link: https://t.co/b3Qhod9DTe #INGV #osservatoriovesuviano #campiflegrei #sorveglianzavulcanica https://t.co/hs5oDZcmYK" /

SUMMARY STATUS OF ACTIVITY
In light of the monitoring data, it is highlighted:

1) SEISMOLOGY: In the week from 06 to 12 May 2024, in the Campi Flegrei area, there were 187 earthquakes with magnitude Md≥0.0 (Mdmax=3.7±0.3) were localized.

2) DEFORMATIONS: In the last month the average value of the lifting speed in the area of maximum deformation is approximately 20±3 mm/month at the Rione Terra GNSS station.

3) GEOCHEMISTRY: There are no significant variations in the geochemical parameters monitored in the reference period with respect to the trends of increase in flows and heating of the system already known hydrothermal. The temperature sensor installed in a fumarole emission 5 meters from the
Pisciarelli's main fumarole showed an average value of ~95°C.

2. EXPECTED SCENARIOS

Based on the current picture of volcanic activity outlined above, no elements are highlighted such as to suggest significant short-term developments.

N.B. Any variations in the monitored parameters, which may lead to a different evolution of the phenomena above described, they will be object of
insights promptly communicated.

Seismology from 06 to 12 May 2024, in the Flegreean fields area, 187 earthquakes were located with magnitude MD≥0.0 (MDMax = 3.7 ± 0.3; Figure 3.1).

Figure 3.1 - Hypocentri of earthquakes with magnitude MD≥0.0 located at the Flegrei fields in the last week. 105 earthquakes occurred during 4 seismic swarms:

● The first, from 22:11 UTC of 06/05/2024 consisting of 70 earthquakes with 0.0≤md≤3.2 (± 0.3), which occurred in the Pisciarelli area and Pozzuoli Academy;

● The second, from 03:46 UTC of 08/05/2024 consisting of 11 earthquakes with 0.0≤md≤2.6 (± 0.3), which occurred in the Pozzuoli area;

● The third, from 10:31 UTC of 10/05/2024 consisting of 5 earthquakes with 0.0≤md≤3.7 (± 0.3), which took place in the Gulf of Pozzuoli;

● The fourth, from 06:38 UTC of 12/05/2024 consisting of 19 earthquakes with 0.0≤md≤1.7 (± 0.3), which occurred in the area of Pozzuoli and in the Gulf of Pozzuoli. Below are the hypocentral parameters of events with MD≥1.0 in the last week:

 

[TornadoFan]

There was just a magnitude 4.4 and several 3.0's at Campi.

 

[bjdeming]

INGV had mentioned a swarm, which is ongoing, but these are bigger. From ANSA (Italian) via GT:

Earthquake at Campi Flegrei: magnitude 4.4 shock, the strongest in 40 years. The seismic swarm continues
The fire brigade operations room received some reports of cracks and falling cornices, but no injuries to people

May 21, 2024, 00:32

Photo ANSA Ciro Fusco

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People on the street in Pozzuoli after the earthquake - ALL RIGHTS RESERVED

The seismic swarm continues in the Campi Flegrei, with tremors of varying intensity: at 11.00 pm another strong earthquake, of magnitude 3.6, was recorded by the National Institute of Geophysics and Volcanology.

Checking for any damage is ongoing.
Campi Flegrei, earthquake at 8.10pm with a magnitude of 4.4

To guarantee assistance to the population, reception areas are being set up, civil protection volunteers are being activated to support local authorities and traffic controls are being strengthened. The verification of the subservice networks and the activation of all coordination centers in connection with each other is also underway. The Department of Civil Protection will continue to monitor the evolution of the situation in constant contact with the territory.

The first significant earthquake felt yesterday in Naples at 7.51 pm was of magnitude 3.5 - with its epicenter in the Campi Flegrei area - and which started a swarm of earthquakes. A subsequent shock was of magnitude 4.4 at 8.10 pm at a depth of three kilometers.

The phenomenon was also felt on the island of Procida, not only in the hilly and central area of Naples, but also in the hinterland municipalities, such as Casavatore and Giugliano in Campania. Reports also from Afragola.
The Campi Flegrei had already been affected by an earthquake swarm this morning, the main shock of which was magnitude 2.3, at 8.50.

The 4.4 magnitude earthquake should be the most intense in the last forty years, the strongest ever recorded since the phenomenon of bradyseism reappeared in the Campi Flegrei. The previous record dates back to the earthquake of September 27th: then the magnitude recorded was 4.2, slightly lower than that of the shock detected by the seismographs last night. And even then, like yesterday, the depth was identified at 3 km, in the Solfatara area. After the quake at 8.10pm - which was preceded by an earthquake swarm that started at 7.51pm - there were many tremors of lower intensity which are still ongoing and in any case of not high magnitude. In particular, at 19.56 of magnitude 1.8, at 20.09 of 1.5, at 2012 of magnitude 1.0 and at 20.16 of 1.2.

The fire brigade operations room received some reports of cracks and falling cornices, external plaster or tiles falling into the house in the areas close to the epicenter of the earthquakes. No harm to people. Local checks are underway.

Schools remain closed in Pozzuoli, informs the Municipality, on the Facebook page. "We are gathered - we read in a post - to address the situation. We are receiving several reports both to the Civil Protection and the Municipal Police, but the lines are overloaded. In case of difficulty, you can also use the messages on the Facebook channel of the Municipality of Pozzuoli, and the mayor Gigi Manzoni, indicating address including number and telephone number. In the meantime, we ask you to remain calm....

 

[bjdeming]

Am following INGV on Facebook now -- they're 3-6 hour updates again. Last one was an hour ago.

 

[bjdeming]

"...tremors shook the whole of Pozzuoli, no area excluded. From Solfatara to via Napoli, from Licola to Monterusciello, Toiano, via Campana, everyone is on the sidewalks, on the walls, in the courtyards, in the squares. Many, many will sleep in cars...

-- Source (autotranslated; they were live on Facebook but not just now)

From that website (autotranslated), there was a landslide after the first shock.

It's seismicity; there is no change in alert level or other notice from volcanologists.

• INGV bulletins (Italian).
• INGV Campi Flegrei page (Italian)
• Alert level: Yellow.
• INGV’s recent activity page (Italian).
• Campi Flegrei emergency plan.

 

[bjdeming]

The last quake currently listed is right now (M1.8 sorry, that's the depth in km; magnitude not yet assigned).

 

[bjdeming]

Civil Protection, half an hour ago (Italian), via GT:

EARTHQUAKE: SEISMIC SWARM IN THE FLEGREAN AREA, CRISIS UNIT ACTIVATED

Reception areas for the population are being set up. Update on May 20th at 11.30pm
Earthquake recording

Following the seismic swarm reported by the National Institute of Geophysics and Volcanology, with a major event of magnitude 4.4 recorded at 8.10 pm, the Department of Civil Protection activated the Crisis Unit in connection with the municipalities of Naples, Pozzuoli and Bacoli, the Prefecture of Naples, the Campania Region, the National Operations Center and the Regional Fire Brigade Command.

At the moment there are no reports of people involved but some injuries to the buildings and some falling rubble have been found.

To guarantee assistance to the population, reception areas are being set up, civil protection volunteers are being activated to support local authorities and traffic controls are being strengthened. The verification of the subservice networks and the activation of all the coordination centers in connection with each other is also underway.

The Department of Civil Protection will continue to monitor the evolution of the situation in constant contact with the territory.

 

[bjdeming]

Four more quakes since the one mentioned above -- they must be small, as I see no news updates. Most likely, thinks this layperson, aftershocks from the M4 and M3-pointers.

Twenty-two minutes later, the total is now 14. I keep getting notices to refresh the page -- haven't seen that in earlier swarms.

 

[bjdeming]

Not counting any more. Seismologists must be putting in heroic efforts to get magnitudes assigned; of those they've gotten thus far, the magnitudes are still 1-pointers. Listed depths are shallow, too, mostly 1 km or less.

 

[bjdeming]

INGV update (Italian) via GT:

Since 19:51 local time on 20 May 2024 (UTC 17:51) a seismic swarm has been underway in the Campi Flegrei area which, until 00:31 local time on 21 May 2024, has preliminarily recorded around 150 earthquakes with duration Magnitude (Md) ≥ 0.0 (95 localized) and a maximum Magnitude (Md) of 4.4 (±0.3).

The Md 4.4 event was the most energetic among those recorded since the beginning of the current bradyseismic crisis that began in 2005. The epicenter is located inside the Solfatara at a depth of 2.6 km.

At present there is no increase in the lifting speed which is currently 2 cm/month. Still at the current state, there are no changes in the trend in horizontal deformations or local deformations of the ground different from the previous trend.

It should be remembered that during the bradyseismic crisis of 1982-84 the ground lifting reached 9 cm per month, and even 1300 seismic events per month were exceeded. Currently, however, approximately 450 events with Md≥0.0 have been recorded in the last month.

The geochemical parameters measured with the continuous stations (Temperature and carbon dioxide flows) do not show significant variations compared to the trends of recent months, other than the well-known increase in temperature and pressure that characterizes the hydrothermal system.

Seismicity is not a predictable phenomenon, therefore it cannot be excluded that other seismic events may occur, even of similar energy to what has already been recorded during the current swarm.

The INGV Vesuvian Observatory continues its ordinary and extraordinary monitoring activities in order to identify even the smallest variations in the monitoring parameters useful for better defining the current phenomenon underway.

The structures of the National Institute of Geophysics and Volcanology (INGV) dedicated to monitoring the Campi Flegrei caldera area are always operational 24 hours a day and on May 21st measurements and sampling will be carried out in some sites of the caldera.

The INGV, with its Naples Vesuvian Observatory Section, is constantly in contact with the national and regional Civil Protection and with the Municipalities involved, as well as with all the Authorities competent for the protection of the territory.


Eventi sismici registrati tra le ore 00.00 del 20 maggio 2024 e le ore 00.31 del 21 maggio 2024. L’evento di maggiore magnitudo è stato registrato alle ore 20.10 del 20 maggio 2024 (Md=4.4±0.3).

 

[bjdeming]

I don't know that a layperson excerpting scientific research counts much, but FWIW the authors who studied seismicity here for that paper linked earlier suggested (emphasis added)

...In the area where the seismicity concentrates below Solfatara/Pisciarelli, Calò and Tramelli36 found low Vp/Vs and high attenuation (confirmed also by De Siena et al.39) that can be interpreted as a vertically elongated highly fractured rock matrix40 filled with vapor that feeds the large gas emission of Solfatara/Pisciarelli. Swarms with the higher magnitude earthquakes mainly occur in tiny volumes below this area where the presence of a rigid caprock acting as a barrier for fluids coming from a deeper magmatic source was evidenced by different authors...

...The high resistivity vertical body extending below Solfatara/Pisciarelli between 0.5 and 2 km (Fig. 8B) was interpreted by the authors as the main upraising pathway of magmatic gases coming from the feeding reservoir located below the caprock...

Layperson interpretation FWIW: This is not an unexpected area for seismicity, where previously quakes up to ~M4.0 could occur. It's a superficial "chimney" of sorts, NOT an open conduit going miles down to the deep reservoir, and the caprock seals it. Tonight's epicenters are within that depth range.

Bringing in INGV's recent update, it sounds as though something might have changed there a bit, but it doesn't seem to have affected the volcanic parameters.

It's a rubble-filled chimney that has high-temp, high-pressure, acidic vapor flowing through it constantly, so yeah, something down there might well shift a bit or fracture now and then. That's what it sounds like might have occurred tonight, this layperson speculates.

They say that they will be going out there tomorrow to see what geochemistry and other measurements might tell them. It's dangerous because of the chance of a hydrothermal explosion -- a well-known hazard at the Solfatara. That's enough! But that's all, I think (FWIW); bigger quakes and escalation of volcanic unrest can't be ruled out, of course, but don't seem very likely.

I wonder what the social reactions to tonight's stresses will be.

 

[bjdeming]

They're doing a superb job with emergency management. Reportedly (autotranslated):

De Luca preaches calm in Pozzuoli «There are no particular worries» Checks in two RSAs for the elderly​

OfGennaro Del Giudice

• PublishedMay 21, 2024

...

POZZUOLI – «The organization is fully in place. The mayor has mobilized civil protection. Honestly, we have no reason for particular dramatization. I came mainly to check the health part but we don't have an emergency. Tomorrow morning checks will be carried out in the two homes for the elderly located near the Solfatara. We are here to tell you that we are close" said the governor Vincenzo De Luca who arrived shortly after midnight in Pozzuoli together with the head of the regional civil protection Italo Giulivo and the mayor of Pozzuoli Gigi Manzoni "From what the experts have told us today we do not have reasons of particular concern. We are here to give you peace of mind and to do what is humanly possible. We will get out of this situation together, which we are monitoring hour by hour." ...



THE SUMMIT – During the night De Luca remained in Pozzuoli where he went to the town hall together with the mayor Gigi Manzoni... «Civil Protection, Municipal Police, Fire Brigade are all out on the street, they are here in Pozzuoli for you, stop them, ask for any assistance. Reception areas have been set up. With me is the President of the Campania Region Vincenzo De Luca and the director of the Regional Civil Protection Italo Giulivo.»...

 

[bjdeming]

I did not expect the swarm to be continuing; in fact, per GOSSIP, some of the epicenters are deeper.

No word from scientists yet, but this layperson now thinks the concept of an enclosed column of rubble adjusting to a shift or fracture in one part might be an oversimplification. Other than that -- ???

Yet the swarm is in the usual location: on the left is the swarm epicenter image from INGV's current update; on the right, from their April bulletin:

Il Mattino is doing live coverage (autotranslated, though sometimes this doesn't work on Italian websites for some reason).

Reportedly (autotranslated), "Twenty-one buildings damaged, 46 families evicted, 454 reports of damage of various degrees, 142 inspections carried out, 4 eviction orders..."

Last night, per that same website, the governor of Campania mentioned dredging work needed in the port, but I've only seen that one subaerial landslide report, nothing about submarine slips and certainly no news of tsunamis.

Tomorrow Italy's prime minister will be holding a meeting (Source, autotranslated), and I read somewhere, too, that a government official told journalists that there is no evacuation ordered but the evacuation routes are clear.

I've looked for but not yet found a new science update. Still watching...

 

[bjdeming]

INGV just released their latest scheduled Campi Flegrei bulletin -- it only goes to the 19th and contains no surprises, but they do put the uplift in perspective.

Per GT:

...From January to early April 2024, the average value of the lifting speed in the area of maximum deformation was approximately 10±3 mm/month (grey band in Figures 4.2 and 4.3).From 9 to 16 April (red band in Figure 4.2 and 4.3) they were recorded at the RITE GNSS station two episodes of soil lifting, respectively of approximately 1 cm (9-10 April) and 0.5 cm (15-16April). These two episodes were also recorded by the other GNSS stations close to RITE in a radius of approximately 2-3 km, with progressively decreasing values moving away from the area maximum deformation (Figure 4.4).Since mid-April (blue band in Figures 4.2 and 4.3), the average value of the lifting speed in the area of maximum deformation it is approximately 20±3 mm/month at the Rione Terra GNSS station(RITE)...

More on this "slow earthquake" (bradyseism") here (PDF download from UC Santa Barbara).

 

[bjdeming]

No quakes listed on GOSSIP for over an hour now.

 

[bjdeming]

A fine sciame, posted INGV after what looks to have been a three-hour lull on GOSSIP, and then I see quakes again, ranging in depth from about 1 to 4 km; the only one with a magnitude thus far is a 1-pointer.

 

[bjdeming]

Those continued until a little before midnight (UTC); there was another ~3-hour lull; more quakes started, including an M3.6, the strongest thus far, AFAIK.

GOSSIP is running about three hours behind, but I don't see any confirmation online of the 4-pointer mentioned in this May 22nd story (autotranslated) -- have only followed them for a couple days but up til now they seemed reliable.

Probably they are referring to the May 20th temblor and are covering public response today to the overall crisis (hopefully, not a widespread response despite the headline).

This is not following the course I've seen in other Campi Flegrei swarms, but that's not necessarily a bad thing -- an impression this layperson got from the paper linked yesterday is that sometimes the caprock below the Solfatara "chimney" does fracture -- and the bradyseism switches from uplift to subsidence.

Nice.

However, other possible developments mentioned, depending on circumstances, are a steam blast, phreatic eruption, or magmatic eruption.

That last possibility is only when the altered rock surrounding the crystalline mush/molten pockets in the reservoir (which apparently is 6 km or more underground) breaks and other circumstances promote exsolution of magmatic gases -- this layperson doesn't think it likely now, FWIW.

Even if it were to happen, all sources I've read would expect a 1538/Monte Nuovo (VEI 2) event.

Fingers crossed for a reversal to subsidence, and at worst, a small hydrothermal blast in the Solfatara field.

 

[bjdeming]

It's not that GOSSIP is running behind; Campi Flegrei has been quiet since midmorning (UTC), per the webicorder, too.

(BTW, today's 3.6 was out in the bay, towards the central western part, not in the Solfatara.)

 

[bjdeming]

INGV is very interested in that western portion of the caldera, reportedly (autotranslated). (PS: The video plays on the original page; it's in Italian but there are views of the Solfatara, INGV at work, etc.)

Here are a couple of links on their MEDUSA system.