Grids
Grids are a dynamic tool used throughout mXrap to form seismic populations, perform calculations and display results. Taking time to set-up site appropriate grids not only makes performing analysis in mXrap more efficient, but it enables others to easily replicate your results. Most sites benefit from a mine and/or orebody wide coarse (sparse) and relatively dense grid, plus additional higher resolution (dense) grids for areas of interest.
Es:Ep Ratio Charts Have Moved
Es:Ep ratio charts can now be found in the ‘Parameter Distribution’ charts for the base filter (Charts > Parameter Distributions) and VSA’s (VSA > Charts > Parameter Distributions).
Select the EsEp option under chart controls to see the cumulative distributions for Es:Ep ratio.
Modifying the Imported Tags Meaning
Depending on your seismic monitoring system setup, you may be importing events with different tags into mXrap. When you open mXrap, any events with imported tags ‘b’ and ‘n’ are turned off by default and all other imported tags (e.g. ‘e’) are turned on. If your database contains other imported tags, you can change the meaning (GOOD, OUTLIER, or BLAST) using: General Setup Windows > Event Tag Editor > Imported Tag Meaning.
Data Anomaly Detection
Anomalies often stem from default values, null entries, manual input or rounding mistakes. While many of these anomalies indicate bad data, not all do. However, if any data is found to be incorrect, it’s important to clear these values to prevent skewing your analysis. Our new Anomaly Detection window provides visualization tools to help you investigate any flagged anomalies and take appropriate action.
Hazard Assessment – Event Rate
The Hazard Assessment application uses a grid-based approach to describe the seismic hazard throughout your mine. Each grid point essentially represents a seismic source with a specific frequency-magnitude relationship. A frequency-magnitude relationship is defined from the MUL, Mmin, b-value, and event rate. The event rate is something we haven’t taken a dive into yet, so we’ll get into it in this post. Event rate sounds like a simple calculation but there are quite a few complexities worth explaining.
Sensitivity Analysis in Hazard Assessment app
A new window has been added to the Hazard Assessment app (Figure 1). The sensitivity analysis aims to quantify the effect of the variation of the input parameters on the hazard. These analyses can also help the user to determine the optimal settings to use for many of the parameters. This window allows the user […]
Updates to Short-term Response Analysis
There have been a number of recent updates to the Short-term Response Analysis app. These include: Chart for determining re-entry using different parameters: This chart gives you values for a particular parameter over time (based on a user-defined time window size and step). A threshold value for that parameter can be set, allowing you to […]
HW–FW filter
For a few months now, a new tool has appeared in the General Analysis app; the hanging wall (HW) and footwall (FW) filter. The HW–FW filter allows you to filter your events based on where they are in relation to ticked survey/s. If more than one survey or plane is used for the HW–FW filter, […]
Energy – moment relationship
Energy and moment are two independent measures of the strength of a seismic event. Their physical meaning and how they are calculated was described in a previous blog post. Analysis of the relationship between the energy and moment of events can provide insight into seismic sources. For example, blasts or ore pass noise, falsely processed […]
Updates to large event analysis
The Large Event Analysis app has receieved a number of upgrades recently. These upgrades focus on analysing seismicity in the immediate time before/after a large event. A new window, called ‘plane based analysis’, allows the user to investigate the source parameters around the location of an event before/after it occurred. The analysis conducted is the […]