Services
Survey Techniques
IP MT CS-NSAMT CSEM GRAV GMAG UASMAG ERT TM DHTEM
Deep 2D & 3D IP / Resistivity & Broadband Magnetotellurics
For the acquisition of Pole-Dipole, Bipole-Dipole, or Dipole-Dipole Induced Polarization (IP) / Resistivity data, multiple spreads of receiver dipoles are deployed along the survey lines. Each spread typically consists of either two Ex-dipoles or an orthogonal pair of dipoles, connected to a gDAS-32 acquisition unit.​
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A transmitter pole, bipole, or dipole is stepped through the array, enabling simultaneous data acquisition across all receiver dipoles. This configuration maximizes the number of n-levels captured in both leading and trailing transmitter-receiver geometries. When two or more survey lines are read at the same time, the array gains a degree of three-dimensionality, making it more suitable for 3D inversion modeling. This approach may be expanded to full 3D array geometries.
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​In addition, the IP receiver array functions as an EMAP-style or sparse tensor array for Broadband Magnetotelluric (MT) data acquisition with the addition of induction coils. This enables the modeling of impedance responses down to several kilometers depth and beyond, providing valuable insight into deep subsurface structures.
Vector-Tensor IP / Resistivity & Broadband Tensor Magnetotellurics
Vector and Tensor IP/Resistivity surveying enables broad and efficient mapping of subsurface chargeability and resistivity distributions. The methodology is designed to maximize area coverage while maintaining sufficient data density to detect the target of interest.
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This is achieved by measuring the electric field generated by a grounded current source (transmitter bipole) at discrete stations, typically arranged in a grid, using orthogonal pairs of receiver dipoles. When both in-phase and quadrature (or primary and secondary) electric field vectors are measured at each station using orthogonal E-field dipoles and a single transmitter, the result is referred to as a Vector IP/Resistivity measurement.
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When two or more transmitter bipoles, oriented differently or located at separate positions, are used in combination with the orthogonal receiver dipoles, a Tensor IP/Resistivity solution can be derived. This approach captures the full directional response of the subsurface by resolving apparent resistivity and IP transfer functions across multiple source field orientations—provided the current density vectors are adequately non-parallel.
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3D forward modeling suggests that maximum investigation depths for Vector data may reach up to 1,000 meters, depending on transmitter-receiver separation (typically 2.5 to 3 km or more). However, such estimates must be considered in light of various factors, particularly the resistivity contrast between the target and the host rock, which plays a critical role in data sensitivity and depth of investigation.
Additional Survey Techniques
We offer a range of complementary geophysical survey methods to support exploration and characterization efforts.
Transient Electromagnetics (TEM)
Moving-In-loop, Coincident-loop, Fixed-loop, 3-component downhole EM
Controlled Source Audio Magnetotellurics
(CSAMT)
Controlled Source Electromagnetics
(CSEM)
Ground Magnetics and Gradiometry
Proton Precession, Overhauser, Potassium & Cesium vapour sensors
Gravity
Digital gravimeter, CS-3M
Consulting and Technical Support
Southernrock maintains consulting agreements with exploration companies and other clients who may not have in-house geophysical teams.
Quality control for contracted or in-house data acquisition
Review and reinterpretation of historical geophysical datasets
Survey design and planning