2D body-wave seismic interferometry as a tool for reconnaissance studies and optimization of passive reflection seismic surveys in hardrock environments

Reflection imaging of complex geology in crystalline environment using virtual-source seismology: case study from the Kylylahti polymetallic mine, Finland

“…The TWEED was used to identify noise sources that were subsequently used for 2D ANSI imaging comparing the all-noise approach (i.e. stacking all the data) vs selective-stacking approach using subsets of the evaluated noise panels (Chamarczuk et al, 2021). At the same time, various AN preprocessing and SI techniques (e.g.…”

“…The geological model was averaged into the above-described four main units and populated with the average P-wave velocities and densities from laboratory measurements on core samples. This model was used, e.g., by Chamarczuk et al (2021) to assess the results of the 2D ANSI based on synthetic and field data, and is used in this paper to validate the results and to support the interpretation. However, it should be noted that the geological model provides a reliable account on the geology only within the extent of the borehole data, as further discussed when describing the interpretation of the passive images presented in this paper.…”

Passive Seismic Structure Imaging of a Coal Mine by Ambient Noise Seismic Interferometry on a Dense Array

“…Ambient noise tomography relies on the extraction of surface waves among stations from cross-correlating and staking continuous seismic recordings. In some cases, ANSI can also be applied in extracting body waves from ambient noise (Roux et al, 2005;Draganov et al, 2007;Nakata et al, 2015;Chamarczuk et al, 2019Chamarczuk et al, , 2021. Currently, ANSI for extracting body waves is mostly used to study large-scale structures, such as the Moho, subduction zone, or the core-mantle boundary (Zhan et al, 2010;Poli et al, 2012;Feng et al, 2017).…”

“…Following the ambient noise data processing procedure of Chamarczuk et al (2021), the data are divided into 30minute segments considering computational efficiency. After the high-pass filtering (4-40 Hz) and frequency domain normalization, the cross-correlation functions (CCFs) are calculated.…”

“…In order to further enhance the quality of the extracted seismic body-waves, we construct second set of VSGs constructed from576 seismic recordings containing only high SNR events. For quantitative comparison between two sets of VSGs, we calculate semblance using the continuous wavelet transform (Chamarczuk et al, 2021). The value of semblance is measured between -1 and 1, and higher values may be interpreted as positively correlated features, and thus similar.…”