Passive seismic surveys have long been applied in the context of exploration studies. Our research focuses on the exploitation of the natural seismicity that is present in passive seismic records and the extraction of useful information of the subsurface from different parts of the earthquake signal. In that scope, we initially install a dense seismological network in an area of interest that will permit the recording of local microseismicity and we detect and locate microearthquakes of very small magnitude that occur within a very close distance from this network. We then exploit the isolated earthquake signals, applying different passive seismic techniques, in order to extract the different pieces of information that they are carrying. More specifically, we use their P- and S-wave first arrivals to perform local earthquake tomography, acquiring a tomographic P- and S-wave velocity distribution of the subsurface below the area of interest. We also extract their P- and S-wave coda to perform reflected-wave seismic interferometry by autocorrelation, which provides zero-offset virtual reflection responses from virtual sources sending energy nearly vertically down below each station of the installed network. The acquired results, which are both individually interpreted and jointly evaluated, provide a valuable insight on the subsurface.@en

As the global need for mineral resources is constantly rising and the exploitable concentrations of these resources tend to become increasingly complex to explore and exploit, the mining industry is in a constant quest for innovative and cost‐effective exploration solutions. In this context, and in the framework of the Smart Exploration action, an integrated passive seismic survey was launched in the Gerolekas bauxite mining site in Central Greece. A passive seismic network, consisting of 129 three‐component short‐period stations was installed and operated continuously for 4 months. The acquired data permitted detection of approximately 1000 microearthquakes of very small magnitude (duration magnitude ranging between –1.5 and 2.0), located within or at a very close distance from the study area. We use this microseismicity as input for the application of passive seismic interferometry for reflection retrieval, using the body waves (P‐ and S‐wave coda) of the located microearthquakes. We retrieve by autocorrelation zero‐offset virtual reflection responses, per component, below each of the recording stations. We process the acquired results using reflection processing techniques to obtain zero‐offset time and depth sections, both for P‐ and for S‐waves. In the context of the present work, we evaluate one of the acquired depth sections, using an existing seismic line passing through the Gerolekas passive seismic network, and we perform forward modelling to assess the quality and value of the acquired results. We confirm that passive seismic reflected‐wave interferometry could constitute a cost‐effective and environmentally friendly innovative exploration alternative, especially in cases of difficult exploration settings.@en