Physica A 340 (2004) 598–606 www.elsevier.com/locate/physa Acoustic emission from periodically perturbed systems: SOC and predictability P. Diodati a ; ∗ , S. Piazza a , F. Marchesoni b a Dipartimento di Fisica, and Istituto Nazionale di Fisica della Materia, Universit a di Perugia, I-06123 Perugia, Italy b Dipartimento di Fisica, and Istituto Nazionale di Fisica della Materia, Universit a di Camerino, I-62032 Camerino, Italy Received 9 February 2004; received in revised form 2 March 2004 Abstract The statistics of acoustic emission (AE) from as diverse processes as volcanic activity (Strom- boli, Italy) and martensitic transformations driven by thermal cycles, is shown to verify the paradigm of self-organized criticality. However, catastrophic event predictability both in labora- tory (the onset of martensitic transformations) and in on-site applications (volcanic seisms and explosions) through the analysis of historical AE series, is not ruled out as long as the emitting samples are subjected to (quasi)periodic low-frequency/large-scale dynamics. c  2004 Elsevier B.V. All rights reserved. PACS: 64.60.Ht; 64.60.My; 81.30.Kf; 91.30.-f Keywords: Acoustic emission; Self-organized criticality; Stromboli; Seismology; Martensitic transformations 1. Introduction The phenomenon of acoustic emission (AE) is associated with the emergence of impulsive elastic waves towards the surface of a sample [1]. Such impulses are gen- erated by a structural energy release from one or more sources in the bulk or, under certain circumstances, on the surface itself, namely by an abrupt variation in the stress eld. Typical AE sources are, for example, moving dislocations [2], structural phase transitions [3], ber breaking in composites [4], microfracture of rocks and friction between surfaces [5]. ∗ Corresponding author. E-mail address: diodati@sica.unipg.it (P. Diodati). 0378-4371/$-see front matter c  2004 Elsevier B.V. All rights reserved. doi:10.1016/j.physa.2004.05.011