Search of Attractors in seismic time series of Caucasus

Abstract

Last years appear controversial publications both on revealing attractors in seismic time series (which means that they can be represented by deterministic chaos model) as well as on theabsence of such ordered structures. So, it seems interesting to study, what methodology should be applied to earthquake time series (ETS) in order to reveal possible attractor structures. There are two main approaches to the problem: i. events in ETSare considered individually; ii. the number of events in ETS in some time window (a seismic rate) is calculated, which is widely used as a proxy of the strain rate in the Earth crust. The study considers how the spatio-temporal parameters of seismic rate calculations affects the nonlinear structures (phase space plots) in low seismicity areas (Batumi region)  as well as before, during main event aftershocks and after strongest Caucasian earthquakes Spitak (1988) and (Racha, 1991).The seismic phase portraits and recurrence plots are constructed for several time windows, different epicentral distances and different magnitude thresholds. The nonlinear structure of laboratory natural and synchronized stick-slip sequences are also considered. The phase  space plots' analysis can reveal some fine details of seismic process dynamics.