Campi Flegrei, new shock at 8,53. A study reveals the complex system of underground waters"

Pozzuoli - While the night passed peacefully (so to speak) and without any major tremors, the morning did not start off well for the residents of the towns and Phlegraean Fields of Naples.

Two shocks: a light one at 8.01 of magnitude 1.1 while the second at 8,53 of magnitude 2.3 clearly felt by the population with epicentre in Antinian Street at a depth of 1,7 kilometers.

Meanwhile, the study 'Chemical and isotopic characterization of groundwater and thermal waters from theCampi Flegrei caldera (southern Italy)', edited by a team from the Vesuvian Observatory of theNational Institute of Geophysics and Volcanology (Ingv-Ov), in collaboration with the Department of Earth and Marine Sciences of the University of Palermo (UniPA-DISTeM), the Department of Earth, Environmental and Resource Sciences of the University of Naples Federico II (UniNA-DiSTAR) and the Department of Earth and Environmental Sciences of the University of Milan-Bicocca (UniMiB-DISAT).

"The work represents the first comprehensive study on the geochemistry of the Phlegraean aquifer since 2005, the start of the current crisis. bradyseismic and has allowed us to recognize the complex processes that control the different characteristics of the waters, including the addition of volcanic-hydrothermal gases and their degassing processes, contributing to the definition of the geochemical model of the system".

Thus Stephen Caliro, technological manager responsible for the geochemical monitoring of the Campania volcanoes at theEngv-Ov, emphasizing how understanding these processes is crucial for monitoring volcanic activity.

"Among the most interesting results - stresses John Chiodini, associate research manager at the INGV - there is the integration of the conceptual model with the numerical physical model of the system, which predicts a gas rise in the Solfatara-Pisciarelli area, and the identification of the interaction between volcanic fluids and aquifers based on the characteristics of the water.

The identified geochemical processes are closely related, but each dominates in specific regions of the hydrothermal system, thus causing the great variability in the composition of groundwater within the caldera.

In the Phlegraean Fields, in fact, cold waters of meteoric origin coexist, thermal bicarbonate waters originating from the interaction with the gases in the peripheral areas of the system, chlorinated waters derived from high temperature saline solutions, and, finally, underground waters of theSolfatara-Pisciarelli area, where the condensation of sulphur-rich steam plays a key role.

"The investigation - adds Alexander Aiuppa, Professor at the University of Palermo - was therefore aimed at better understanding the chemical processes that influence the composition of groundwater. Through the analysis of 114 samples collected in an extensive measurement campaign between 2013 and 2014, we developed a geochemical model that allowed us to describe the evolution of the interaction of meteoric water with hydrothermal saline solutions and volcanic gases during its underground journey.

The collected data have therefore allowed to develop an advanced conceptual model useful to highlight and interpret possible future changes in groundwater chemistry and process dynamics.

"The results of this study - concludes Mauro A. DiVito, Director of the INGV-OV - have allowed us to design and implement a permanent multi-parameter network for monitoring the waters in the caldera, active since 2018 and continuously evolving, which represents an essential tool for detecting changes in the system and recognizing any signs of a resumption of volcanic activity.