Imaging shallow structures using interferometry of seismic body waves generated by train traffic

Train-induced vibrations act as potential powerful high-frequency source for imaging subsurface with higher resolution than typical ambient noise interferometry. In this study, we present results of seismic interferometry applied on three days of railroad traffic data recorded by an array of seismographs along a railway in Dublin, Ireland. Our virtual shot gathers show significant surface and body wave energy that could be used for seismic interferometry. Reflection sections obtained with our interferometry approaches applied on selected time windows of train-induced vibrations is consistent with nearby borehole data and an active seismic profile. The consistency of the results given by these approaches confirms that train-generated vibrations represent a valuable source of signal for high-resolution subsurface imaging. Furthermore, our results show spurious arrivals that are due to the train geometry and also the cross-correlation approach that needs consideration for body wave interferometry studies.