Executive Summary: The passive seismic survey of the La Cruces mine site was initiated during discussion between partners of the PACIFIC and INFACT H2020 projects in December 2018. The initial design for the deployment covered a large area, about 7 x 4 km extending to the north and south of the mine but this was reduced to a smaller tighter 2 x 1 km array in February 2019. A collapse of the northside of the open pit then eliminated the possibility of placing nodes to the west of the pit and this resulted in an even smaller array. Data treatment proved to be very difficult for several reasons. The array was smaller than originally planned, but more importantly a significant proportion of the nodes, about 30%, were placed in the pit. The large differences in elevation between adjacent nodes and the differences in orientation of pit walls and terraces introduced unanticipated difficulties in processing the seismic data. 

We used 33 days of passive seismic records to retrieve the fundamental mode of Rayleigh waves propagating in the subsurface. We mostly used man-made ambient noise generated in the vicinity of the mine in the period band [0.3 - 1.5] s. Strong anthropogenic noise in the middle of the array forced us to use one-bit normalization and very intense pre-processing to retrieve usable cross-correlation signals. We were able to pick individual group and phase velocity dispersion curves from correlations computed between the majority of sensor pairs for stations separated by less than 2 km. We retained about 15% of all possible dispersion curves after a thorough quality check based on expert visual inspection. The aperture of the array and the frequency content of the noise allowed us to invert a velocity model down to 500 m depth. Long offsets are mainly discarded inducing a poor coverage of the central part of the pit. A high velocity anomaly beneath the northern part of the site where topography is not a problem and where the array is denser can be resolved and could correspond to the massive sulphide ore body at depth. The depth of cover in the north-eastern part of the study area is well represented by the iso-velocity surface of 750 m/s.

Virtual Sources of Body Waves from Noise Correlations in a Mineral Exploration Context.

The extraction of body waves from passive seismic recordings has great potential for monitoring and imaging applications. The low environmental impact, low cost, and high accessibility of passive techniques makes them especially attractive as replacement or complementary techniques to active‐source exploration. There still, however, remain many challenges with body‐wave extraction, mainly the strong dependence on local seismic sources necessary to create high‐frequency body‐wave energy. Here, we present the Marathon dataset collected in September 2018, which consists of 30 days of continuous recordings from a dense surface array of 1020 single vertical‐component geophones deployed over a mineral exploration block. First, we use a cross‐correlation beamforming technique to evaluate the wavefield each minute and discover that the local highway and railroad traffic are the primary sources of high‐frequency body‐wave energy. Next, we demonstrate how selective stacking of cross‐correlation functions during periods where vehicles and trains are passing near the array reveals strong body‐wave arrivals. Based on source station geometry and the estimated geologic structure, we interpret these arrivals as virtual refractions due to their high velocity and linear moveout. Finally, we demonstrate how the apparent velocity of these arrivals along the array contains information about the local geologic structure, mainly the major dipping layer. Although vehicle sources illuminating array in a narrow azimuth may not seem ideal for passive reflection imaging, we expect this case will be commonly encountered and should serve as a good dataset for the development of new techniques in this domain.

Executive summary: To create synergies and optimise project results and impact, the PACIFIC project dedicates the Work Package 7 to collaboration and clustering with other research projects under the same call topic, and other relevant projects in the field funded by Horizon 2020 (H2020). PACIFIC partners thus collaborate with ongoing research initiatives in the mineral exploration area.

During the first year of the project, the collaboration took several forms, that are developed in this deliverable according to the following axes:

1. Joint activities organised with other projects in the cluster;
2. Participation in international events and conferences with other H2020 related projects;
3. Ongoing and future collaborations.

This report must be understood as the first of three reports on joint events with other research projects, that will be produced through the duration of the project: D7.2 (M12), D7.3 (M24) and D7.4 (M36). Thus, the information provided, especially in the “Ongoing and future collaborations” section, will be reviewed or updated in next reports. 

Executive summary: Across the globe, the mineral industry is seeking new technologies to replace or complement existing geological, geochemical and geophysical methods to improve exploration efficiency at depth and to help design safer and more productive mines. These industries are increasingly using seismic methods for a wide range of commodities including base metals, uranium, diamonds, and precious metals. Seismic methods usually can be used for direct targeting of mineral deposits but particular care must be taken during acquisition and processing of the data. To achieve the best results, different processing sequences based on the target of the project are applied. Here we compare and discuss how such workflows are used when treating active seismic data in order to provide a basis for their use in the development of the passive seismic methods that form the basis of the PACIFIC project.

Technique now possible due to improvements in lithium batteries which power monitoring equipment

Article in the Canadian press by Jeff Walters · CBC News · Posted: Jun 12, 2019 1:28 PM ET  https://www.cbc.ca/news/canada/thunder-bay/thunder-bay-pacific-new-exploration-1.5172168 

Executive summary: This report summarises recommendations for improved communications surrounding mining-related activities, based on an overview of existing communications through a behavioural science lens (Deliverable 6.1), and a computer-based behavioural experiment run in 2019 (Deliverable 6.2).
The work was undertaken by the Behavioural Research Unit of the Economic and Social Research Institute, a research group specialising in understanding how people process complex information and use it to make decisions. This is pertinent in the context of the PACIFIC project as people’s comprehension of mining-relating activities (and attitudes towards the same) relies on individuals processing complex information about risks and benefits from a range of sources.
The goal of this research is not to design communication tools that will best ensure that a company can secure a ‘social license to operate’. Rather, it is to inform best practice for communication strategies that promote understanding and empower stakeholders to make well-informed decisions, whatever the outcome may be. This is particularly important at a time where misinformation is becoming more widespread.
Herein we have made a suite of recommendations for improved communication about mining-related activities that may be utilised by a range of end-users (agencies, geological surveys, companies, etc.). For this project the research has primarily considered the general public as the target audience. That said, many of the findings presented have relevance to communications with otherstakeholders, such as shareholders, policy makers, and regulators.
As mentioned above, the recommendations are based off an overview of existing communication materials, as well as the results of a first behavioural experiment. This experiment had some unexpected findings, which will be investigated further in follow-up experiments in early 2021. The results of these may provide further insights that will be communicated in due course.

All you want to know about the PACIFIC project (Passive seismic techniques for environmentally friendly and cost efficient mineral exploration) is there !

PACIFIC - H2020 research project in mineral exploration (pacific-h2020.eu)

Funded by the European Commission and coordinated by the Universite Grenoble Alpes, PACIFIC is a research project in the field of mineral exploration. The project aims at developing new exploration techniques that respect the environment and incur relatively low costs. Join us in Grenoble on 27-28 October to find out how the PACIFIC consortium has been conducting fundamental and applied research to develop two radically new and complementary mineral exploration techniques, both based on passive seismic imagery.

The detailed programme and registration platform will soon be available. Stay tuned !