Wave propagation modelling in various microearthquake environments using a spectral-element method

TL;DR

This paper demonstrates the application of spectral-element methods to simulate wave propagation in diverse microearthquake environments, highlighting the method's capabilities and challenges across different scales and geological settings.

Contribution

It introduces a spectral-element simulation approach for complex microearthquake environments, including underground mines, unstable slopes, and laboratory samples, with comparative analysis of synthetic and observed waveforms.

Findings

Successful simulation of wavefields in 2D and 3D models

Identification of challenges in spectral-element simulations

Comparison of synthetic and observed waveforms

Abstract

Simulation of wave propagation in a microearthquake environment is often challenging due to small-scale structural and material heterogeneities. We simulate wave propagation in three different real microearthquake environments using a spectral-element method. In the first example, we compute the full wavefield in 2D and 3D models of an underground ore mine, namely the Pyhaesalmi mine in Finland. In the second example, we simulate wave propagation in a homogeneous velocity model including the actual topography of an unstable rock slope at Aaknes in western Norway. Finally, we compute the full wavefield for a weakly anisotropic cylindrical sample at laboratory scale, which was used for an acoustic emission experiment under triaxial loading. We investigate the characteristic features of wave propagation in those models and compare synthetic waveforms with observed waveforms wherever possible. We illustrate the challenges associated with the spectral-element simulation in those models.