A 10.5 km2 3D seismic survey was acquired over the Kylylahti mine area (Outokumpu mineral district, eastern Finland) as a part of COGITO-MIN (COst-effective Geophysical Imaging Techniques for supporting Ongoing MINeral exploration in Europe) project, which aimed at development cost-effective geophysical imaging methods exploration. The cost-effectiveness our case related to fact that an active-source accomplished by using receiver spread originally designed passive survey. array recorded...

Abstract We present a method for automatic detection and classification of seismic events from continuous ambient‐noise (AN) recordings using an unsupervised machine‐learning (ML) approach. combine classic recently developed array‐processing techniques with ML enabling the use in routine processing data. test our on dataset large‐number (large‐N) array, which was deployed over Kylylahti underground mine (Finland), show potential to automatically process cluster volumes AN Automatic sorting...

The main issues related to passive-source reflection imaging with seismic interferometry (SI) are inadequate acquisition parameters for sufficient spatial wavefield sampling and vulnerability of surface arrays the dominant influence omnipresent surface-wave sources. Additionally, long recordings provide large data volumes that require robust efficient processing methods. We address these problems by developing a two-step evaluation event detection (TWEED) method body waves in recorded...

Passive seismic experiments have been proposed as a cost-effective and non-invasive alternative to controlled-source seismology, allowing body–wave reflections based on interferometry principles be retrieved. However, from the huge volume of recorded ambient noise, only selected time periods (noise panels) are contributing constructively retrieval reflections. We address issue automatic scanning noise data by large-N array in search energy (body–wave events) utilizing convolutional neural...

Summary We present the results of adapting seismic interferometry (SI) for reflection imaging in mineral exploration. use a unique dataset one-month ambient-noise recordings acquired with large-N array (~1000 receivers) deployed regular grid (50 m receiver interval, 200 line interval) directly above known mineralisation and underground mine infrastructure at Kylylahti polymetallic located Eastern Finland. Ambient-noise study area is dominated by road traffic activities (both surface...

Summary We present an overview of the seismic exploration initiatives at Outokumpu ore district in Eastern Finland, with new results from COGITO-MIN active-passive survey 2016. Through this example Outokumpu, we aim to demonstrate possibilities different types data, including emerging, cost-effective methodologies, for stages mineral exploration. Building on two earlier reflection 2D campaigns area, project acquired active and passive data Kylylahti sulphide mine site within district....

Abstract. For the first time, we apply a full-scale 3D seismic virtual-source survey (VSS) for purpose of near-mine mineral exploration. The data were acquired directly above Kylylahti underground mine in Finland. Recorded ambient noise (AN) are characterized using power spectral density (PSD) and beamforming. Data have most energy at frequencies 25–90 Hz, arrivals with velocities higher than 4 km s−1 wide range azimuths. Based on PSD beamforming results, created 10 d subset AN recordings...

Most of the ambient-noise studies are performed with sensor arrays located at surface. Passive recordings containing seismic arrivals from subsurface sources could be seen as having a geometry resembling reverse vertical profiling (RVSP). In such scenarios, intersource seismic-interferometry technique can used to redatum surface receivers source positions resulting in virtual shot gathers depth. The success interferometric processing primarily requires that correlation panel created process...

SUMMARY Here we analyse ambient noise (AN) data generated during drilling of exploration boreholes and recorded using a dense array deployed over one the numerous shallow iron-ore mineralization targets in Pilbara region (Western Australia). Drilling drilling-related operations were reoccurring sequence as described by drillers’ field notes, which created rare opportunity to AN time segments when only type technical process was predominantly active. Consequently, most sources did not overlap...

Abstract Distributed acoustic sensing (DAS), deployed on dark telecom fiber, is well-positioned to play a significant role in seismic monitoring networks because of the combination large aperture, fine spatial resolution, broadband sensitivity, and ubiquitous presence unused telecommunication fibers many areas world. In this study, we explore feasibility dark-fiber array noisy environment for detecting small explosions. We test effectiveness template matching detection low-frequency blasts...

FORGE (Frontier Observatory for Research in Geothermal Energy) is an underground field laboratory located Utah, western United States, and sponsored by the US Department of Energy. The site situated above a young, hot granitoid formation. has been used as testbed institutions interested enhanced geothermal systems. As part recent research work conducted at site, new deviated well was drilled adjacent to previously stimulated well. Both wells were into granite volume. Circulation tests...

Natural cyclical stress perturbations, including wet and solid earth tides, coupled with repeatable seismic monitoring approaches, provide a tool for understanding the elastic properties of rocks at depth. Ocean in particular, perturb overburden pore pressure, affecting hydraulic rock properties. The recent emergence distributed acoustic sensing (DAS) seismology using existing dark telecom fiber offers an unprecedented opportunity to instrument seas oceans networks large aperture, fine...

Summary Recent theoretical advances have demonstrated that passive surveys utilizing ambient seismic noise allow new possibilities for imaging and may provide an alternative controlled-source surveying. Related to the COGITO-MIN project, a experiment employing set of 45 three-component seismometers recording about 30 days was conducted in Kylylahti polymetallic mine area Eastern Finland. Acoustic forward modelling carried out get idea on how well reflections could be retrieved with...