We study oscillations recorded at Stromboli and Campi Flegrei by different sensors. Seismicity and deformation are investigated on several time scales in order to identify the basic elements of their interaction, whose understanding should provide new insights on the predictive models. At Stromboli, a departure from the equilibrium state is marked by solid tide variations in a certain frequency band. At Campi Flegrei diurnal to annual solid tides modulate an increase of volcanic activity.
We analyse tiltmeter time series recorded from April 2015 to March 2019 at three borehole instruments installed at Campi Flegrei caldera (Italy). We evaluate the crustal response in terms of ground tilting to external excitations of medium/long-period tidal constituents.
The results indicate that the tidal tilting is mainly controlled by the local stress field distribution and rheology; in addition, seasonal exogenous factors like rainfalls play a role in modulating the ground deformation.
We present a detailed analysis of the atypical low frequency seismicity occurred at Mt. Vesuvius in 2003-2018. The different decay patterns of the spectra, the existence of families as well as single events, the wide seismogenic volume, indicate that these events are caused by distinct source mechanisms: slow brittle failure in dry rocks and resonance of fluid-filled cracks. On these basis, we classified the earthquakes as Low Frequency (LF) and Long Period (LP).
Thanks to the availability of a portable absolute gravimeter allowing field operations, in 2015 a dense absolute gravity network was established in Campi Flegrei and till 2019 five surveys were carried out. Results suggest that the present activity may be due to the alternating recharge/discharge of fluids in the surface hydrothermal system. They also confirms the feasibility of this methodology for volcano monitoring, and encourage replacing the relative networks with absolute ones.
The Solfatara volcano (Italy), is monitored by a thermal infrared camera ground network handled by INGV. The dataset processed in this work consists of daily maximum temperatures time-series from 25 April 2014 to 31 May 2019. After a pre-processing, PSD's were calculated, filtering in [15–120] day band, to check if characteristic periodicities exist. Most of the periodicities are ascribable to ambient factors, while 18.16 and 88.71 days have a possible endogenous origin.
Spectral analysis has been applied to seismic events recorded at Vesuvius volcano to test a new tool for a fast event classification. We computed two spectral parameters, central frequency and shape factor from the spectral moments. The results show that volcano-tectonic earthquakes and low frequency events are distinguishable though the spectral moments. Since the computation of spectral parameters is easy and fast, it may become an effective tool for classification in observatory practice.
We studied the subsoil structure of the Campi Flegrei area using both spectral ratios and array techniques (f-k and MSPAC) applied to seismic noise recorded by three different array. By means of joint inversion of dispersion curve and spectral ratio we obtained a Vs model, that is in a good agreement with the stratigraphic information available in the area. In areas such as Campi Flegrei the definition of the velocity model is a crucial issue to characterize the physical parameters of the medium
In this paper the main results of the regional program Rad Campania for the monitoring and the assessment of the radon risk are analyzed. An analysis of all data collected is presented in order to improve the radon reserach field and enrich the scientific literature of important results and new methodologies to be applied and extended in other similar cases.
Fumarolic fields with near-surface temperature <100°C are very common features of volcanoes. Their space/time variability is controlled by hydro-meteorological conditions, vapor flow and permeability, reflecting changes of volcanic activity. Since the thermal monitoring of these fumaroles is a low cost, up-to-date technique, it has been successfully applied in volcanic surveillance programs of Italian active volcanoes, giving useful insights on the evolution of their activity state.