General Analysis App

Description:  The General Analysis App provides tools for the general analysis of mine induced seismicity. These tools include combinations of complex spatial and range filters, charts, tables and 3D views.

Grid Based Analysis

Description: The Grid Based Analysis app provides the tools to evaluate the spatial distribution of seismic source parameters. Based on specified input parameters, a three-dimensional spatial kernel interpolation is performed to assess the mean value of seismic source parameters on a given grid. Cumulative source parameters like cumulative apparent volume are assessed through a variable bandwidth kernel interpolation of which the bandwidth is a function of the source size. The b-value is evaluated by implementing a robust algorithm for finding the magnitude of completeness and b-value pair for each grid point.Post-processing includes the three-dimensional display of results using colour, transparency, and gridpoint scaling. Filtering of gridpoints and the events contained in the volumes represented by the gridpoints can be performed. This grid based event filter can also be used for general analysis.

Plane Fitting App

Description:
The Plane Fitting App provides a tool for fitting a plane through selected seismic events. The app performs principal component analysis (PCA) on the spatial data provided and generates a plane normal to the minor axis with the extent determined by the major and intermediate axis.

A stereonet is provided showing the pole of the plane from the PCA. Planes are also fitted through three-event combinations of the selected events. The pole distribution of these planes is shown as contours on the stereonet. A goodness of fit analysis is performed and a simplified ranking assigned to the best-fit plane.

The plane can be exported as a *.pnt file for later re-use in a ‘distance to’ filter or for display in other apps and programs.

Hazard Assessment

Description:
The grid-based seismic hazard assessment app assesses the current seismic hazard for the mine based on the recent seismic history. An assessment of a mine-wide value for Mmax is performed based on the work presented by Kijko & Singh (2011) and Lasocki & Urban (2011). The spatial distribution of b-value and event density for the recent history is performed and used as input to a probabilistic evaluation of the spatial distribution of the seismic hazard. The results of this probabilistic calculation are presented in space in several ways through iso surfaces and pseudo-volumetric rendering.

The probabilistic distribution of the peak-particle velocity is calculated for minodes and seismic hazard map in terms of the probabilistic evaluation of the strong ground motion being produced. The minodes can be interrogated and the contribution of different sources evaluated.

Seismic-Production Balance

Description:
The Seismic-Production Balance app focuses on investigating the link between seismicity and production, specifically the balance between the two. Adjustment of certain seismic parameters enables the user to view the Energy Balance chart and view the influence of increasing production volume on the energy in the system. In addition to Potency charts, the app also includes some other parameters plotted as a function of production volume for further analysis. These parameters include cumulative number of events versus production volume, displacement versus production volume, and potency versus production volume.

Rockburst Damage Potential

Description:
This app is based on the Rockburst Damage Potential (RDP) system developed by Dan Heal (2010). This app provides an environment to edit the E1, E2, E3 and E4 components of the RDP system as well as to display and interrogate these components, the excavation vulnerability potential (EVP), the PPV factor and the RDP.

Large Event Analysis

Description:
The Large Event Analysis app provides the user with an easy and quick first assessment of the distribution of strong ground motion at excavations for a given event. Plots are given for a uniform and a double couple shear mechanism. Users can choose events from the database performing ‘what-if’ analyses by overriding some or all the parameters. The app is limited to a linear distance analysis using a given strong ground motion relationship and does not take into account any wave-medium and wave-excavation interaction.

Omori Analysis Tools

Description:
The Omori Analysis app provides several windows each dedicated to specific tasks. The window provides the ability to select a blast or blasts from the blast database for which the ‘Omori chart’ is provided for the events within a specified volume around the blast/s and a specified time after the blast/s. If more than one blast is selected, the individual and the stacked cumulative event distribution are provided.

Another window is dedicated to performing a best-fit of the Modified Omori Law (MOL) to the events associated with a selected blast. The chosen volume and time window and the parameters for the MOL are saved. Another window dedicated to the analysis of these results is provided. The statistical and spatial distributions of the MOL parameters are assessed based on the saved parameters from the MOL best-fit.

The spatial and statistical distributions of the MOL parameters provide input to the re-entry analysis which is provided in another window. The re-entry assessment is based on the work by Vallejos & McKinnon (2010) and can be used in real time assessment of re-entry or for the back analysis of historical data to develop re-entry protocols.

Seismic Event Quality

Description:
The Seismic Event Quality app provides tools to evaluate the quality of the database and highlight potential bad quality data. Noise, blasts, and bad quality data can be tagged and excluded from analysis in other apps. The Seismic Event Quality app includes potential blast detection, spatial filters and outlier detection.

System Design

Description:
The System Design app provides tools to assess the seismic system sensitivity in 3D space. The app uses the seismic database and sensor file for a chosen stable period to derive the Dx-mmin relationship. Where Dx is the distance to the Xth sensor, typically X = 5 mmin is the system sensitivity. This relationship is then used to plot the system sensitivity in 3D space for a given array of seismic sensors. A general indication of the location quality for different magnitudes is also provided based on given sensor arrays. The effect of losing or adding sensors in the array can be evaluated interactively.

Although further development was done since the publication of the following paper, it still provides a summary of the concepts used in this app:
Wesseloo, J. (2011) Empirical methods for assessment of seismic system sensitivity, Transactions of the Institutions of Mining and Metallurgy: Section A, Mining Technology, vol. 120 (2), pp. 105–111.

Seismic Monitoring

Description: The use of the Basic Seismic Monitoring app is intended for mine control room operators to monitor the latest seismicity and communicate event alerts and exclusion areas depending on site-specific rules. Each site can set up their own event alert and exclusion settings in the Basic Seismic Monitoring (Admin) application and then the main application is a simplified interface for the viewer. Key features include:

• Automatic events updating (no need to keep pressing ‘Reload Data’!).
• Popup event alert notifications (to alert user when window is hidden/minimised).
• Popup system alert notifications (triggered from threshold time without new events).
• Plot exclusion areas and isolate single mine areas (e.g. single level plans).
• Automatic view – quick zoom/rotate to the exclusion areas on screen.
• Distance measurement – get the distance from any survey point to the nearest event alert.

Short Term Response Analysis

Description: The Short Term Response Analysis app allows users to visualise the seismic response to different triggers (blasts and large seismic events). They analyse the temporal response to assess re-entry times and the spatial response to assess exclusion zones. There are also tools for evaluating the response based on different trigger types (date, blast type, blast size, etc) – which can help the user better understand the nature of their seismic responses.

Event Density ISOs

Description: The Event Density Isosurfaces app allows users to create isosurfaces for different levels of event density. This is a powerful analysis tool, giving users better information about seismic activity rates when the event counts are high (due to high seismic activity and/or sensitive sensor arrays).