The Seismicity in the Southern Tyrrhenian Area and its Neural Forecasting

The Southern Tyrrhenian basin is a region characterized by complex tectonics and large-scale geodynamic deformations, and its seismicity has been recently recognized as following fractal laws in its five dimensional set (magnitude, time and space). In particular, the time occurrences of earthquakes are found to follow a significant fractal clustering within the interval ranging from 16 minutes to 24 hours; for longer intervals, the time clustering regime was not significantly different from that of a random process. An artificial neural network is applied here to the same seismicity data set and further evidence of the nonlinear dynamic process, for which the fractal approach failed, is obtained. The monthly values of magnitude predicted by extrapolation are found to be in fair agreement with the historical data.