GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 The role of long-range correlatons and memory in earthquake occurrence D. Zaccagnino 1* , L. Telesca 2 , C. Doglioni 1,3 1 Sapienza University, Earth Sciences Department, Rome, Italy 2 Insttute of Methodologies for Environmental Analysis, Natonal Research Council, Tito, Italy 3 Isttuto Nazionale di Geofsica e Vulcanologia (INGV), Rome, Italy. Seismicity occurs because of strain accumulaton in the britle crust due to the acton of tectonic forces. However, this background process is just one of numerous ones afectng earthquake occurrence. In the long run it controls the frequency of large events (Neely et al., 2023); conversely, at our tme scales it is likely one of the less impactul. The spatal and temporal evoluton of seismic sequences has been proposed to be driven by fuid migraton and frictonal instability and to be afected by stress perturbatons as well as anthropic actvites, rheology, structural propertes of fault systems and by the tectonic regime (e.g., Rice & Cocco, 2007; Ellsworth, 2013; Ross & al., 2017). Consequently, several empirical relatonships have been found connectng propertes of seismicity with geophysical observables (pore pressure, diferental stress, statc fricton etc.). We suggest that local variability of some routnely investgated parameters can be clarifed considering few all-encompassing physical principles instead of advocatng several hardly testable physical mechanisms. To provide an observatonal example, we analyse a high- defniton regional seismic catalogue of seismicity in Central Italy (Tan et al., 2021). We identfy a chain of relatonships, startng with the propertes of inherited structures and tectonic stress gradients directly afectng the fractal propertes of fault systems, which, in turn, have an impact on the frequency-magnitude scaling of earthquakes. It produces implicatons for the duraton of seismic sequences, complexity of the seismogenic source and the compositon of moment tensors (Zaccagnino & Doglioni, 2022). Our approach has the advantage to be valid regardless of the specifc rheology, lithology, tectonic setng, and state of stress. In this regard, we guess that such connectons between seismicity and structural propertes of fault systems are universal, being due to the acton of feedback mechanisms and memory processes.