Seismicity dynamics and earthquake predictability

Abstract

Abstract. Many factors complicate earthquake sequences, including the heterogeneity and self-similarity of the geological medium, the hierarchical structure of faults and stresses, and small-scale variations in the stresses from different sources. A seismic process is a type of nonlinear dissipative system demonstrating opposing trends towards order and chaos. Transitions from equilibrium to unstable equilibrium and local dynamic instability appear when there is an inflow of energy; reverse transitions appear when energy is dissipating. Several metastable areas of a different scale exist in the seismically active region before an earthquake. Some earthquakes are preceded by precursory phenomena of a different scale in space and time. These include long-term activation, seismic quiescence, foreshocks in the broad and narrow sense, hidden periodical vibrations, effects of the synchronization of seismic activity, and others. Such phenomena indicate that the dynamic system of lithosphere is moving to a new state -catastrophe. A number of examples of medium-term and short-term precursors is shown in this paper. However, no precursors identified to date are clear and unambiguous: the percentage of missed targets and false alarms is high. The weak fluctuations from outer and internal sources play a great role on the eve of an earthquake and the occurrence time of the future event depends on the collective behavior of triggers. The main task is to improve the methods of metastable zone detection and probabilistic forecasting.

Generation and propagation of stick-slip waves over a fault with rate-independent friction

“…Modelling of the frictional sliding is an important tool for understanding the initiation and the development of rupture, and also, the healing of the faults. Many models and numerical methods are developed to describe seismic activities and the supershear fracture/rupture propagation (Noda and Lapusta, 2013;Lapusta and Rice, 2003;Lu at al., 2009;Lapusta et al, 2000;Sobolev, 2011;Bak and Tang, 1989;Harris and Day, 1993).…”

Dynamic analysis of earthquake phenomena by means of pseudo phase plane

“…It is not clear which method, if any, is superior for all topological properties. However, optimal values based on the behaviour of the autocorrelation function are the easier to compute [13].…”

“…When the stress is sufficiently high to break through the asperities, a sudden motion of the plates occurs, accompanied by energy release, causing an earthquake [12]. Over the last decades several models were proposed to describe seismic activity [13][14][15][16][17][18][19][20][58][59][60]. In certain models, the asperities on the fault surfaces resemble fractals sliding over each other, explaining the fractal scaling behaviour that has been observed in earthquake phenomena [21].…”

Earthquake forecasting: a possible solution considering the GPS ionospheric delay

“…Richon et al, 2003), geodetic variations (abnormal ground elevations, e.g. Sobolev, 2011), changes in the chemical composition of underground water (e.g. Ryabinin et al, 2011), change in temperature of the aquifers, changes in the Earth's magnetic field, changes in the Earth's electric field (e.g.…”