GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.1 GNGTS 2023 crustal volume or a fault) rather than strain accumulation. Hence, the range can be defined as the difference between the maximum and minimum amount of seismic energy released by a crustal volume throughout the period τ . Simulating the inflow-outflow process like in a Hurst-style problem allows us to better understand the memory behavior in the earthquake generation process. To this end, we apply a simple single-fault model for earthquake simulation that relies on the following basic assumptions: 1. the magnitudes of earthquakes follow a Gutenberg-Richter law with a maximum magnitude equal to the total energy stored at that time in the fault; 2. inter-event times are drawn from exponential distribution (i.e., as in a Poisson process); 3. an earthquake is generated (following the first assumption) when the total accumulated strain reaches the maximum energy that can be stored in the fault (i.e., in a crustal volume). Modeling earthquakes according to these three simple and intuitive assumptions can lead to interesting and complicated earthquake patterns, such as the one in the example shown in Figure 1, which mimics earthquake clustering. The earthquake rate increases near fault rupture (i.e., when the total accumulated energy approaches the maximum storable energy) and remains at a high level until a strong earthquake or a series of earthquakes dissipate the energy available in the fault. The final time series are examined through the R/S analysis to inspect the value of the Hurst exponent. Fig. 1 – Example of earthquake occurrence pattern with long memory.