The 4D imaging of the source of ground deformation at Campi Flegrei caldera (southern Italy)

2012 ◽  
Vol 117 (B8) ◽  
pp. n/a-n/a ◽  
Author(s):  
Luca D'Auria ◽  
Flora Giudicepietro ◽  
Marcello Martini ◽  
Riccardo Lanari
2020 ◽  
Author(s):  
Stefano Vitale ◽  
Roberto Isaia ◽  
Jacopo Natale ◽  
Francesco D'Assisi Tramparulo

<p>We investigated the major episodes of dome growth in the Campi Flegrei caldera occurred during the last period of large eruptive activity (Epoch 3, between 5.5 and 3.5 ka), and in the historical time. The first doming event occurred at the start of Epoch 3  where the caldera floor raised for at least 100 m. Following the Plinian eruption of Agnano-Monte Spina (AMS, 4.55 ka), a new uplift phase occurred with the set up of several lava domes (e.g., Olibano, Accademia and Solfatara cryptodome), the Averno-Solfatara  (AVS, 4.3 ka) and Astroni (AST, 4.2 ka) eruptions. This unrest episode was accompanied by severe and widespread faulting and fracturing well recorded in the stratigraphic record (Vitale et al., 2019). Finally, the last episodes of doming occurred before the eruption of Monte Nuovo volcano (MN, 1538 CE) and in the last century (1950-1985 CE). The 1538 CE uplift reached a maximum vertical displacement of ca. 15 m, whereas the 1950-1985 events reached a total dislocation of ca. 4 m. In order to study the former ground deformation pattern, we reconstructed the top surface of the La Starza succession, the latter formed by marine-transitional sediments deposited between 15 and 5.5 ka deposited in large part of the caldera floor. We used information from onland well-logs and seismic profiles in the Gulf of Pozzuoli. The same approach was used for the top surface of the younger marine succession, called Pozzuoli Unit (PU) (Isaia et al., 2019), emplaced following the AMS eruption and predating the AVS eruption. Subtracting the historical deformation pattern and considering the sea-level change in that time frame, we observe that the center of vertical deformation was located, for both Top Starza and Top PU surfaces, close to the Cigliano vent, and therefore not coinciding with the 1538 CE and recent deformation center, both defined by the same deformation center located close to the town of Pozzuoli. The resulting surfaces well mark local deformations related to the activity of major faults and the minor caldera formed following the AMS Plinian eruption. The restoring of the deformation of major faults with the Okada’s fault model has furnished useful information about the amount of displacement and rates of the faults' activity in the last ca. 6 ka.</p><p>Isaia, R., Vitale, S., Marturano, A., Aiello, G., Barra, D., Ciarcia, S., Iannuzzi, E., Tramparulo, F.D.A., 2019. High-resolution geological investigations to reconstruct the long-term ground movements in the last 15 kyr at Campi Flegrei caldera (southern Italy). Journal of Volcanology and Geothermal Research, 385, 143-158. doi: 10.1016/j.jvolgeores.2019.07.012</p><p>Vitale, S., Isaia, R., Ciarcia, S., Di Giuseppe, M. G., Iannuzzi, E., Prinzi, E. P., Tramparulo, F.D’A., Troiano, A. 2019. Seismically induced soft‐sediment deformation phenomena during the volcano‐tectonic activity of Campi Flegrei caldera (southern Italy) in the last 15 kyr. Tectonics, 38(6), 1999-2018.</p>


Geosciences ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 185
Author(s):  
Simona Tripaldi ◽  
Sergio Scippacercola ◽  
Annarita Mangiacapra ◽  
Zaccaria Petrillo

The recent signs of reawakening at Campi Flegrei caldera (Southern Italy) received a great deal of attention due to the issues related to the volcanic risk management in a densely populated area. This paper explores relations between ground deformations, seismicity and geochemical time series in the time span 2004–2016. The aim is to unravel primary processes of unrest and the related indicators which may change in time. Data structure and interactions among variables were examined applying the clustering analysis, the correlations and the Granger causality test. The hierarchical agglomerative clustering detected two sub-periods which were further investigated. In both sub-period causal links were observed between variables while correlations did not appear and vice versa. Thus, well established formal approaches are required to study causal relations. Granger test results indicate that during 2004–2011 the awakening unrest could be mainly ascribed to hydrothermal system pressure fluctuations, probably induced by deep-rooted fluids injection, and that ground deformation together with CO2/H2O appears the most suitable geo-indicators. The 2011–2016 sub-period is characterized by enhanced dynamical connectivity. Granger test results suggest that the unrest is driven by a more localized and shallower thermohydromechanical engine. CO/CO2, He/CH4 and ground deformation velocity are mutually interacting appearing the most suitable geo-indicators.


2020 ◽  
Author(s):  
Jacopo Natale ◽  
Stefano Vitale ◽  
Roberto Isaia ◽  
Francesco D'Assisi Tramparulo ◽  
Luigi Ferranti ◽  
...  

<p>The Campi Flegrei caldera (southern Italy) is characterized by over one-third of its extension lying below the sea. In the last 15 ka the caldera floor has suffered hundreds of meters of ground deformation alternating uplift and subsidence episodes in response to the activity of the volcanic system. The evidence of significant uplifts is witnessed by the occurrence of marine sequences exposed on land, both along a 30 m high La Starza cliff and in numerous well logs. However, most of these sediments are currently hidden below the sea. This work aims to reconstruct the marine counterpart of the infill by using large multiscale reflection seismic data (>100 profiles) and an accurate seismic facies analysis. The latter consisted in the study and<br>comparison of seismic attributes, scaled to the resolution of the different datasets, to their geological analogs on land. Furthermore, by observing the changes in the pattern of on-lap terminations, thickness, amplitude, and distribution of erosive features of different horizons, we tentatively ascribed these sequences to the well-known continental deposits. The study of the whole sequence above the Neapolitan Yellow Tuff (15 ka) allowed us to gather relevant information about the relationships between stratigraphic record, ground deformation and sea-level changes. In particular, the reconstruction of buried surfaces gave us hints on the evolution of the volcanic system including the role of faults in terms of estimation of displacement and relationships with the different epoch of major eruptive activity.</p>


Tectonics ◽  
2021 ◽  
Author(s):  
Roberto Isaia ◽  
Maria Giulia Di Giuseppe ◽  
Jacopo Natale ◽  
Francesco D'Assisi Tramparulo ◽  
Antonio Troiano ◽  
...  

2013 ◽  
Vol 9 (4) ◽  
pp. 635-640 ◽  
Author(s):  
Giuseppe Vilardo ◽  
Guido Ventura ◽  
Eliana Bellucci Sessa ◽  
Carlo Terranova

2021 ◽  
Author(s):  
Waheed Gbenga Akande ◽  
Quan Gan ◽  
David G. Cornwell ◽  
Luca De Siena

<p>Modelling volcanic processes at active volcanoes often requires a multidisciplinary approach, which adequately describes the complex and ever-dynamic nature of volcanic unrests. Campi Flegrei caldera (southern Italy) is an ideal laboratory where numerical modelling of injection-induced seismicity could be tested to match the observed seismicity. In the current study, thermal-hydraulic-mechanical (THM) effects of hot-water (fluid) injections were investigated to ascertain whether the observed seismicity (past and ongoing seismic swarms) could be quantitatively reproduced and modelled in isothermal or non-isothermal approximations. Fluid-flow modelling was carried out using a coupled TOUGHREACT-FLAC<sup>3D</sup> approach to simulate THM effects of fluid injections in a capped reservoir, where the sealing formation serves as a geological interface between supercritical reservoir and fractured shallow layers of the caldera. Results from previous seismic, deformation, tomographic and rock physics studies were used to constrain the model for realistic volcano modelling. The results indicated that fluid injections generated overpressure beneath the caprock and subjected it to different stress regimes at its top and bottom, and this prompted deformation. Thus, caprock deformation, triggered by injection-induced basal compressional forces and top extensional fractures, is a critical factor determining the required timing for pressure build-up and fault reactivation, and magnitudes of seismicity. Higher fluid injection rates and temperature contrasts, heterogeneity due to fault and its contrast with the host rock, and caprock hydraulic properties were among the identified secondary factors modulating fault reactivation and seismicity. Simulation results revealed that seismicity can be better modelled in isothermal (HM) approximations. A comparative study of the THM-modelled seismicity and 4-month-long (August 5<sup>th</sup> to December 5<sup>th</sup>, 2019) seismic monitoring data recorded at the Osservatorio Vesuviano showed that our model reproduced the magnitudes and depths (~2.5 Ms within 2 km) at the onset of the ongoing unrests on October 5<sup>th</sup>, 2019. However, the model could not adequately reproduce the highest magnitude (3.3 Ms at 2.57 km) seismicity on April 26<sup>th</sup>, 2020 observed since 1984 major unrests.</p><p> </p>


2021 ◽  
Author(s):  
Camilla Marino ◽  
Luigi Ferranti ◽  
Jacopo Natale ◽  
Marco Sacchi ◽  
Marco Anzidei

<p>Appraisal of morphodepositional markers tied to ancient sea-levels in high-resolution seismic profiles together with geo-archaeological markers along the coast of the Pozzuoli Bay provided insights into the vertical deformation of the submerged part of the Campi Flegrei caldera (Southern Italy).</p><p>The collapse of the central part of the Campi Flegrei caldera is associated with the eruption of the Neapolitan Yellow Tuff (NYT) at ~15 ka. The NYT caldera collapse was followed by central dome resurgence associated with alternations of fast uplift and subsidence displacements that accompanied with discrete phases of intra-caldera volcanic activity. Previously, the evolution of ground movement in the Campi Flegrei caldera has been reconstructed using marine deposits uplifted onland or archaeological evidence and historical accounts and thus offers a mainly 2D appraisal of the deformation pattern. However, a complete reconstruction of post-collapse deformation suffers of the limitation that nearly two-thirds of the caldera are submerged beneath the Pozzuoli Bay.</p><p>We contribute to fill this gap by providing a reconstruction of offshore and coastal deformation through estimation of the vertical displacement of morphodepositional markers in high-resolution seismic reflection profiles and geoarchaeological markers directly surveyed at shallow depths. Our interpretation reveals the occurrence of different sediment stacking pattern whose provides evidence of rapid and oscillating ground movements. Whereas the offshore morphodepositional markers provide displacement information for the last ~12 ka, for the last ~2 ka our interpretation is supported by ancient Roman sea-level indicators. The multi-dataset analysis has allowed disentangling the signal related to the post-caldera dynamics from a broader deformation signal that affects this part of the extensional margin of the Apennines.</p><p>The integration of offshore data in the study of past episodes of ground deformation, by yielding a more complete picture of the ground motions associated to the post-collapse evolution of the Campi Flegrei caldera, bears a significant contribution for a 3D reconstruction of this high-risk resurgence caldera. Besides, the multidisciplinary approach presented here can be relevant for investigations of other calderas spanning the sea-land transition.</p>


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