Offshore ground movements in the Campi Flegrei caldera during the last ~12 ka

2021 ◽  
Author(s):  
Camilla Marino ◽  
Luigi Ferranti ◽  
Jacopo Natale ◽  
Marco Sacchi ◽  
Marco Anzidei
Keyword(s):  
High Resolution ◽  
Ground Deformation ◽  
Vertical Displacement ◽  
Ground Movement ◽  
Campi Flegrei ◽  
Caldera Collapse ◽  
Deformation Pattern ◽  
Central Dome ◽  
Ground Movements ◽  
Campi Flegrei Caldera

<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>

Doming and faulting processes driving ground deformation at Campi Flegrei caldera (southern Italy): a modeling for the last 6 ka

2020 ◽  
Author(s):  
Stefano Vitale ◽  
Roberto Isaia ◽  
Jacopo Natale ◽  
Francesco D'Assisi Tramparulo
Keyword(s):  
Southern Italy ◽  
Ground Deformation ◽  
Vertical Displacement ◽  
Time Frame ◽  
Plinian Eruption ◽  
Tectonic Activity ◽  
Campi Flegrei ◽  
Deformation Pattern ◽  
Campi Flegrei Caldera ◽  
Caldera Floor

<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>

scholarly journals Granger Causality Analysis of Geophysical, Geodetic and Geochemical Observations during Volcanic Unrest: A Case Study in the Campi Flegrei Caldera (Italy)

Geosciences ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 185
Author(s):  
Simona Tripaldi ◽  
Sergio Scippacercola ◽  
Annarita Mangiacapra ◽  
Zaccaria Petrillo
Keyword(s):  
Granger Causality ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Test Results ◽  
Time Data ◽  
Causality Test ◽  
Campi Flegrei Caldera ◽  
System Pressure ◽  
Deformation Velocity ◽  
Granger Test

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.

Correlation between submerged and continental infill at Campi Flegrei caldera: insights on the volcano-tectonic events of the last 15 kyr

2020 ◽  
Author(s):  
Jacopo Natale ◽  
Stefano Vitale ◽  
Roberto Isaia ◽  
Francesco D'Assisi Tramparulo ◽  
Luigi Ferranti ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Relevant Information ◽  
Seismic Facies ◽  
Campi Flegrei ◽  
Sea Level Changes ◽  
Volcanic System ◽  
Campi Flegrei Caldera ◽  
Reflection Seismic ◽  
Continental Deposits ◽  
Seismic Facies Analysis

<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>

scholarly journals Four Years of Continuous Seafloor Displacement Measurements in the Campi Flegrei Caldera

2020 ◽  
Vol 8 ◽  
Author(s):  
Prospero De Martino ◽  
Sergio Guardato ◽  
Gian Paolo Donnarumma ◽  
Mario Dolce ◽  
Tiziana Trombetti ◽  
...  
Keyword(s):  
Campi Flegrei ◽  
Radial Deformation ◽  
Deformation Pattern ◽  
Monitoring Networks ◽  
Spherical Source ◽  
Marine Research ◽  
Campi Flegrei Caldera ◽  
Volcanic Source ◽  
Seafloor Deformation ◽  
Environmental Measures

We present 4 years of continuous seafloor deformation measurements carried out in the Campi Flegrei caldera (Southern Italy), one of the most hazardous and populated volcanic areas in the world. The seafloor sector of the caldera has been monitored since early 2016 by the MEDUSA marine research infrastructure, consisting of four instrumented buoys installed where sea depth is less than 100 m. Each MEDUSA buoy is equipped with a cabled, seafloor module with geophysical and oceanographic sensors and a subaerial GPS station providing seafloor deformation and other environmental measures. Since April 2016, the GPS vertical displacements at the four buoys show a continuous uplift of the seafloor with cumulative measured uplift ranging between 8 and 20 cm. Despite the data being affected by environmental noise associated with sea and meteorological conditions, the horizontal GPS displacements on the buoys show a trend coherent with a radial deformation pattern. We use jointly the GPS horizontal and vertical velocities of seafloor and on-land deformations for modeling the volcanic source, finding that a spherical source fits best the GPS data. The geodetic data produced by MEDUSA has now been integrated with the data flow of other monitoring networks deployed on land at Campi Flegrei.

scholarly journals A 2-D FEM thermal model to simulate water flow in a porous media: Campi Flegrei caldera case study

2012 ◽  
Vol 19 (3) ◽  
pp. 323-333 ◽  
Author(s):  
V. Romano ◽  
U. Tammaro ◽  
P. Capuano
Keyword(s):  
Porous Medium ◽  
Water Flow ◽  
Thermal Model ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Magmatic Fluid ◽  
Geothermal System ◽  
Thermal Source ◽  
Campi Flegrei Caldera ◽  
Vertical Displacements

Abstract. Volcanic and geothermal aspects both exist in many geologically young areas. In these areas the heat transfer process is of fundamental importance, so that the thermal and fluid-dynamic processes characterizing a viscous fluid in a porous medium are very important to understand the complex dynamics of the these areas. The Campi Flegrei caldera, located west of the city of Naples, within the central-southern sector of the large graben of Campanian plain, is a region where both volcanic and geothermal phenomena are present. The upper part of the geothermal system can be considered roughly as a succession of volcanic porous material (tuff) saturated by a mixture formed mainly by water and carbon dioxide. We have implemented a finite elements approach in transient conditions to simulate water flow in a 2-D porous medium to model the changes of temperature in the geothermal system due to magmatic fluid inflow, accounting for a transient phase, not considered in the analytical solutions and fluid compressibility. The thermal model is described by means of conductive/convective equations, in which we propose a thermal source represented by a parabolic shape function to better simulate an increase of temperature in the central part (magma chamber) of a box, simulating the Campi Flegrei caldera and using more recent evaluations, from literature, for the medium's parameters (specific heat capacity, density, thermal conductivity, permeability). A best-fit velocity for the permeant is evaluated by comparing the simulated temperatures with those measured in wells drilled by Agip (Italian Oil Agency) in the 1980s in the framework of geothermal exploration. A few tens of days are enough to reach the thermal steady state, showing the quick response of the system to heat injection. The increase in the pressure due to the heat transport is then used to compute ground deformation, in particular the vertical displacements characteristics of the Campi Flegrei caldera behaviour. The vertical displacements range from 1 cm to 10 cm in accordance with the mini uplift, characterizing the recent behaviour of the caldera. The time needed to move fluid particles from the bottom to the upper layer (years) is compatible with the timing of the mini uplift.

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
Keyword(s):  
Southern Italy ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Campi Flegrei Caldera ◽  
4D Imaging
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