Ground deformations represent one of the main hazards in mining areas and they are related to the presence of natural and anthropogenic cavities. Monitoring mining activity is crucial to mitigate risks associated to catastrophic collapses through identification of likely premonitory signs.
We propose a monitoring service based on a new algorithm, full 4D Local Earthquake Tomography that has been applied to both natural and induced seismicity (injection phase at a geothermal borehole) and has been proven to by-pass the main problems related to existing competing solutions. Local Earthquakes Tomography (LET) is a well-established low-cost tool for the imaging of the sub-surface structures, alternative to expensive active seismic surveys. Our solution addresses the main concern related to the application of standard LET algorithms as a time-lapse exploration tool, by automatic evaluation of identified time-variations within the mined rocks volumes. Results are ready to be implemented in a traffic light decision-making system.
We integrate classical ambient noise and 3D – Time Lapse LET with an original fully 4D tomographic solution and ground deformation for monitoring mining and underground activities. Our main innovation respect to competing solutions are:
- Provision of a complete suite of LET algorithms;
- Integration of satellite (SAR and GPS) geodetic data and land based tomographic systems improving:
- Space-Time ground deformation monitoring (Deformation maps over time)
- Rock volume analysis aimed to collapses and fracturing detection and prevention
- Earthquake monitoring