Abstract
The occurrence of aftershocks is a signature of physical systems exhibiting relaxation phenomena. They are observed in various natural or experimental systems and usually obey several non-trivial empirical laws. Here we consider a cellular automaton realization of a nonlinear viscoelastic slider-block model in order to infer the physical mechanisms of triggering responsible for the occurrence of aftershocks. We show that nonlinear viscoelasticity plays a critical role in the occurrence of aftershocks. The model reproduces several empirical laws describing the statistics of aftershocks. In case of earthquakes, the proposed model suggests that the power-law rheology of the fault gauge, underlying lower crust, and upper mantle controls the decay rate of aftershocks. This is verified by analysing several prominent aftershock sequences for which the rheological properties of the underlying crust and upper mantle were established.
Highlights
The occurrence of aftershocks is a signature of physical systems exhibiting relaxation phenomena
We consider a cellular automaton realization of a nonlinear viscoelastic slider-block model in order to infer the physical mechanisms of triggering responsible for the occurrence of aftershocks
We show that nonlinear viscoelasticity plays a critical role in the occurrence of aftershocks
Summary
The occurrence of aftershocks is a signature of physical systems exhibiting relaxation phenomena They are observed in various natural or experimental systems and usually obey several non-trivial empirical laws. The observed aftershock sequences usually obey several well-defined, non-trivial empirical laws in magnitude, temporal, and spatial domains[4,14,15,16] In many cases their characteristics follow scale-invariant distributions[16,17,18]. Where τ and c are characteristic time scale parameters and the exponent p defines the power-law decay rate This is one of the oldest and robust statistical features of aftershocks[1,20] and signifies a time delay in the stress field relaxation after a main shock. It explains the functional form of the Omori-Utsu law and gives physical interpretation of its parameters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
