April 24th 2023, Perth, Australia
RockSigma and IGM Geotechnical are independent businesses whose core values align. Both companies are equally dedicated to data quality, how it affects seismic analysis, and the safety and production processes that depend on it.
Wille Törnman, RockSigma founder and specialist in seismic hazard assessment, met with Izak Gerhard Morkel, Director and Principal consultant at IGM Geotechnical, to discuss the reliability of current seismic analysis techniques.
Both Wille and Izak note that a huge challenge faced by the mine seismology industry is to ensure that the data being used is of a good quality. The old adage goes “Garbage in, Garbage out” and this is still very much the case today in this industry, driven by the complexity involved in recording seismic events and dealing with large changes happening as mining progresses.
The flow diagram below illustrates the data collection and processing steps, from occurrence to an entry in the final database. Izak who is one of the creators of this well known diagram comments, “Seismologists have to make assumptions at each step of the process, which leads to small errors compounding down the process chain.”. Many of these errors cannot be removed due to the limitations of current technology.
Wille adds, “All measurements come with a small error, and as things are added up, so are the errors.”. Izak continues to say, “Without confidence in our measurements, there can be no confidence in our analyses, and therefore we are required to remember these small errors and understand how they should be accounted for.”
A straightforward solution is to carry all the uncertainties along the steps of the processing chain, combining them into resulting uncertainties of the calculated parameters. In the engineering world this is typically referred to as accounting for the Known Unknowns. For example, this includes uncertainties in: arrivals, velocities, attenuations, angle of arrivals, propagation paths and also uncertainties in the model itself.
Having access to the final uncertainty gives the quality assurance needed to trust the result and to make most use of the data in all subsequent analyses, ranging from mapping of damages to creating trustworthy hazard assessments.
“When analyzing seismic activity, being able to see the uncertainties at all stages of processing really helps with robustness”, Wille says. Izak agrees, “Seeing the uncertainty in our final results allows us to know how much confidence we can have in results, which in turn leads to informed intelligent decision making.”
About IGM Geotechnical
IGM Geotechnical is a Geotechnical consultancy aimed at assisting Mining companies with addressing seismic risk, and other Geotechnical challenges associated with high stress mining.
Izak Gerhard Morkel is the Director at IGM Geotechnical and a qualified Geotechnical Engineer and Seismologist with over 15 years of experience addressing the challenges associated with high stress in the most seismically active mines in the world.
About RockSigma
RockSigma is a Swedish software company. We revolutionize the field of seismic processing by providing a sensor neutral, open data platform with fast, accurate and precise seismic processing.
Wille Törnman