Executive summary: This document reports on the risks identified during field operations carried out in the second year of the PACIFIC project, from June 2019 to June 2020. During this period, two surveys were carried out at the Kallak iron ore project in Sweden and another was conducted at the Kaiserstuhl site in Germany.
The document builds on D5.2 - Environmental and Safety Risk Database adopted in 2018, and D5.3 Annual Risk Management Report 1. The procedures outlined in these documents were implemented during the surveys. No injuries were reported in either survey and impact on the local environment was found to be minimal.

Executive summary: This document reports on the risks identified during field operations carried out in the first year of the PACIFIC project, from June 2018 to June 2019. During this period, two surveys were carried out, one at Stillwater Canada Inc. (SCI)’ s Marathon PGU-Cu Project (“Marathon”), and another one at the Las Cruces site in Spain, an operating mine run by Cobre Las Cruces. The document builds on D5.2 – Environmental and Safety Risk Database adopted in 2018.
The procedures outlined in these documents were implemented during the surveys. No injuries were reported in either survey and impact on the local environment was found to be minimal.

Executive summary: This deliverable gathers risks related to safety or environmental issues relevant for PACIFIC activities. For each type of issue, the risks/hazards are listed with their score before and after mitigation and the corresponding control measures. A safe working procedure is also described. This database will serve as reference for the ESMC – Environmental and Safety Risk Management Committee – for follow-up during the course of the project.

An ultimate Charter governing the roles, responsibilities, composition and membership of the Committee will be outlined and implemented prior to the activation of PACIFIC programs.

Executive summary: A key goal of the PACIFIC project is to develop methodologies for the extraction of body waves from passive seismic data, for use in the environmentally sustainable environments. Recovering body waves from ambient noise data has proved to be challenging as they are usually weak and ambient noise fields are rich in surface waves. Here we propose and test a method, based on the Radon Transformation, that helps suppress surface waves and enhance reflected body waves. The method exploits the ‘moveout’ differences between reflected body (hyperbolic) and surface waves (linear) and is tested on synthetic 2D & 3D model data prior to its application to ambient noise field data. We refer to it as Radon Correlation. Synthetic tests are very encouraging, showing clear body wave recovery that cannot be seen in raw cross-correlated data. Using these synthetics to have a choice of parameters, we then move to field passive data from the Marathon site within PACIFIC. We generate virtual shot gathers by applying Radon Correlation to single virtual sources into a linear array of receivers. Again, results are very encouraging with clear reflected body wave recovery from the ambient noise data and determined by clear hyperbolic arrivals on the virtual shot gathers. There is a hint that using time windows that contain active blast seismic coda possibly further enhances body wave recovery. Finally, velocity analysis on these virtual shot gathers leads to a P-wave velocity model that compares well with models derived from surface wave dispersion analysis of the same ambient noise data. However, these models are not currently publicly available and hence are not shown here, in this report.

Executive summary: Permitting of the seismic survey and the acquisition of data are the first steps in WP3, the pilot test of the passive reflection seismic technique in the Marathon deposit. The processing and development stages of the Work Package rely directly on the successful acquisition of ambient seismic noise data from the Marathon test site.
Between September 17th and October 26th of 2018, at the Marathon test site, a 1025 sensor passive seismic survey was completed. The sensors equipment was rented from SAExploration. 1024 sensors were successfully deployed; however, only 1019 were recovered. The loss of sensors was due to animal activity or being buried by a rock slide.
The grid design was composed of two overlapping grids, a 416-sensor array and a 609-sensor profile line. The array had a grid spacing of 150m, while the profile line had a grid spacing of 50m. Both grids designs were configured along the main noise source of Lake Superior in the direction of 250deg to the west.
The sensors selected for the survey were ZL and C1, vertical direction sensors with a 10hz range. Once the sensors were retrieved, they were shipped back to SAExploration for download. The data was successfully downloaded and shipped to Sisprobe for analysis.

Retrieving reflection arrivals from passive seismic data using Radon correlation

Since explosive and impulsive seismic sources such as dynamite, air guns, gas guns or even vibroseis can have a big impact on the environment, some companies have decided to record ambient seismic noise and use it to estimate the physical properties of the subsurface. Big challenges arise when the aim is extracting body waves from recorded passive signals, especially in the presence of strong surface waves. In passive seismic signals, such body waves are usually weak in comparison to surface waves that are much more prominent. To understand the characteristics of passive signals and the effect of natural source locations, three simple synthetic models were created. To extract body waves from simulated passive signals we propose and test a Radon-correlation method. This is a time-spatial correlation of amplitudes with a train of time-shifted Dirac delta functions through different hyperbolic paths. It is tested on a two-layer horizontal model, a three-layer model that includes a dipping layer (with and without lateral heterogeneity) and also on synthetic Marmousi model data sets. Synthetic tests show that the introduced method is able to reconstruct reflection events at the correct time-offset positions that are hidden in results obtained by the general cross-correlation method. Also, a depth migrated section shows a good match between imaged horizons and the true model. It is possible to generate off-end virtual gathers by applying the method to a linear array of receivers and to construct a velocity model by semblance velocity analysis of individually extracted gathers.

 Charlie Beard's presentation can be viewed on the link https://www.youtube.com/watch?v=g_qdwQGHNhs 

Download the PACIFIC flyer https://www.pacific-h2020.eu/wp-content/uploads/pacific-flyer.pdf 

Executive summary: Active seismic sources such as explosives, air guns and vibroseis generate energetic P-waves well suited for reflection seismic studies. However, they can have negative environmental impacts and are expensive, both of which have motivated the development of passive seismic methods. Passive seismic methods utilise ambient noise from meteorological and anthropogenic activity. They have been successful for surface wave recovery but extracting body waves for reflection imaging is still a challenge. A key goal of the PACIFIC project is to develop methodologies for extracting body waves from passive seismic data, and for using these body waves for subsurface imaging. This report describes the development of synthetic velocity models that characterise the geological structure and seismic reflectivity at the Marathon Cu-PGE prospect Ontario, Canada. Synthetic seismic signals generated in these models will then be used to develop and test processing procedures for body wave recovery and body wave imaging. A first velocity model consists of two vertical sections obtained by interpolation of lithological contacts identified in drillholes. One section is perpendicular to the dip of the main gabbro intrusion, the other is parallel. A second model is obtained by blind 3D interpolation between drillholes and uses velocities measured on hand samples and drill core. Work in progress uses dedicated geological modelling software to generate a 3D block model that honors geological structures and cross-cutting relationships. A recently acquired downhole acoustic log avoids negative velocity biases from microfractures that can be introduced during depressurisation (e.g. of drill core). This will be used to calibrate a new velocity forward model.