Methods
IMENSUS applies a range of geophysical methods to support mineral exploration, mine planning, safety assessments, and post-mining projects. While each project requires a method-specific approach, our main focus lies on active seismic exploration, a powerful but still underused technology in the mining industry.
Active Seismic Survey
How the method works
Active seismic exploration uses controlled seismic waves to investigate the subsurface. The waves travel through the ground and react to changes in rock properties, geological boundaries, faults, fractures, and layers. By recording and processing these signals at the surface, detailed 2D and 3D subsurface models can be developed.
What geotechnical information it provides
Because seismic waves are influenced by the stiffness, density, and condition of the rock mass, seismic data provides information closely linked to the mechanical behaviour of the subsurface. It can support the evaluation of seismic velocities, stiffness contrasts, rock mass boundaries, fault and fracture zones, and potential zones of weakness, all relevant for mine planning, slope stability, and geotechnical risk assessment.
How seismic differs from other methods
Magnetic, gravity, electrical, and electromagnetic methods mainly indicate contrasts in magnetic, density, or electrical properties. Active seismic exploration adds a different layer of information: it is especially strong in structural imaging and in identifying how geological units, discontinuities, and mechanically relevant zones continue at depth.
How it complements other methods
Active seismic exploration can be used as a standalone method, but it is even more powerful when combined with geological mapping, drilling data, and other geophysical methods. It adds independent structural and geotechnical information, helps validate existing interpretations, and strengthens the overall subsurface model.
Why it matters in mining
For mining projects, seismic exploration can improve the understanding of ore body geometry, depth, faults, fracture systems, and structural controls. This creates a stronger basis for mine expansion planning, slope and waste dump stability assessments, and more cost-effective follow-up drilling programs.
Additional Geophysical Methods
Geoelectrical Surveys
What is measured: Electrical properties of the subsurface, mainly resistivity.
Result: Models showing electrical contrasts that indicate different rock types, alteration zones, mineralization, fractures, cavities, or groundwater conditions.
Mining use: Supports mineral exploration, target evaluation, near-surface mapping, groundwater assessment, environmental investigations, and the validation of geological models.
Electromagnetic Surveys
What is measured: Variations in the electrical conductivity of the subsurface, caused by conductive minerals, rock properties, alteration, fractures, or groundwater conditions.
Result: Conductivity models and anomaly maps showing potential conductive zones, geological boundaries, structural features, and exploration targets.
Mining use: Supports the detection and interpretation of conductive mineralization, especially sulfide-related systems, and complements seismic, geoelectrical, magnetic, and gravity data for more reliable subsurface models.
Magnetic Surveys
What is measured: Variations in the Earth’s magnetic field caused by differences in magnetic minerals and rock properties.
Result: Magnetic anomaly maps that help identify lithological contrasts, faults, contacts, intrusions, and regional geological structures.
Mining use: Supports large-scale exploration, structural interpretation, target generation, and the mapping of geological trends across extensive project areas.
Gravity Surveys
What is measured: Small variations in the Earth’s gravitational field caused by differences in rock density.
Result: Gravity anomaly maps and density-based subsurface models showing major geological structures, basins, intrusive bodies, faults, and density contrasts.
Mining use: Helps interpret deeper geological architecture, identify large-scale exploration targets, support regional modelling, and complement seismic, magnetic, and electrical datasets.
Passive Seismic Survey/Ambient Noise Tomography
What is measured: Natural and human-made background vibrations of the ground, recorded over time by passive seismic sensors. No artificial seismic source is required.
Result: 1D or 2D seismic velocity models, mainly showing shear-wave velocity contrasts within the subsurface. These models can indicate structural boundaries, fault zones, fracture systems, lithological contrasts, and mechanically relevant zones.
Mining use: Supports mineral exploration, structural interpretation, and the evaluation of deeper or complex subsurface conditions. Ambient Noise Tomography can help improve geological models, identify target structures, complement active seismic and other geophysical methods, and provide additional information for mine planning and geotechnical assessments.
Where project requirements go beyond our core geophysical services, IMENSUS support the coordination of local service providers, experts, or institutions. This allows project-specific tasks to be integrated into the overall workflow while taking regional conditions and local capabilities into account.
Satellite data analysis
Project-related evaluation of satellite-based information, including InSAR data and digital elevation models.
Geological services
Support from local geological experts for field mapping, sampling, geological validation, and site-specific interpretation.
Drilling services
Coordination of core drilling or comparable drilling activities through qualified local drilling contractors where required for the project.