Europhys. Lett.
Volume 72, Number 4, November 2005
Page(s) 678 - 684
Section Interdisciplinary physics and related areas of science and technology
Published online 21 October 2005
Europhys. Lett., 72 (4), pp. 678-684 (2005)
DOI: 10.1209/epl/i2005-10292-x

Memory in self-organized criticality

E. Lippiello1, L. de Arcangelis2 and C. Godano3

1  INFM, UdR Napoli and Università di Napoli "Federico II" - 80125 Napoli, Italy
2  Dipartimento di Ingegneria Informatica and INFM-Coherentia Seconda Università di Napoli, 81031 Aversa (CE), Italy
3  Dipartimento di Scienze Ambientali and INFM, Seconda Università di Napoli 81100 Caserta, Italy

received 27 July 2005; accepted in final form 28 September 2005
published online 21 October 2005

Self-organized criticality (SOC) successfully describes power law behaviour of size distribution in many natural phenomena. However, it does not consider time correlations between events and therefore it is unable to reproduce the time occurrence behaviour, namely the inter-event time distribution, extremely relevant for many problems. We present a SOC model with memory: events are nucleated not only as a consequence of the instantaneous value of the local field with respect to the firing threshold, but on the basis of the whole history of the system. We apply the model to the study of earthquake occurrence and we obtain, without any parameter tuning, excellent agreement with inter-event time and magnitude distributions from the Southern California Catalog.

89.75.-k - Complex systems.
05.65.+b - Self-organized systems.
91.30.Dk - Seismicity: space and time distribution.

© EDP Sciences 2005