Evidence of non–extensivity and complexity in the seismicity observed during 2011-2012 at the Santorini volcanic complex, Greece.

During the last months of 2011, an increase in the seismicity rates of the volcanic complex system of Santorini Island, Greece, was observed. In the present work, the temporal distribution of seismicity, as well as the magnitude distribution of earthquakes, has been studied. Using the concept of Non-Extensive Statistical Physics (NESP) along with the time evolution of Tsallis ’ information measure, we have investigated the inter-event time distribution between the successive earthquakes. Non-Extensive Statistical Physics, which is a generalization of Boltzmann-Gibbs statistical physics, seems a suitable framework for studying complex systems. The observed inter-event time distribution of Santorini seismicity can be described (fitted) with NESP models exceptionally well. This implies the inherent complexity of the Santorini volcanic seismicity, the applicability of NESP concepts to volcanic earthquake activity and the usefulness of NESP in investigating phenomena exhibiting multifractality and long-range coupling effects. 1