Energy flows in the earthquake source before and after the main shock

TL;DR

This study investigates the energy flow directions in earthquake sources before and after main shocks, using a novel experimental approach and data analysis to understand foreshock and aftershock behaviors relative to the epicenter.

Contribution

It introduces a non-standard experimental technique and analytical method to study energy flow directions in earthquake sources, linking foreshock and aftershock movements to energy propagation.

Findings

Foreshocks tend to approach the epicenter before a main shock.

Aftershocks tend to move away from the epicenter after a main shock.

A method for verifying the convergence and divergence based on magnitude dependence is proposed.

Abstract

We proceeded from general physical concepts based, on the one hand, on the Umoff-Poynting theorem, and on the other, on the phenomenological theory of earthquakes, and formulated the following question: What are the directions of energy flows in the earthquake source before and after the formation of a main rupture in it? A non-standard technique for experimental research of this issue has been developed. The epicentral zone of the main shock is considered as a kind of track detector, and foreshocks and aftershocks are considered as marks (tracers) marking the propagation in the source of some factor that has energy and stimulates the excitation of foreshocks and aftershocks in a stressed-strained rock mass. By processing and analyzing a large volume of observation data, it was found that over time, foreshocks, on average, approach the epicenter of the main shock, while aftershocks, on the contrary, move away from the epicenter. A method is indicated for verifying the result by studying the magnitude dependence of foreshock convergence and aftershock divergence. Keywords: foreshock, aftershock, main rupture, evolution equation, nonlinear diffusion waves, fault length.