2D Electrical Resistivity Imaging Survey

2D Electrical resistivity tomography (ERT) or electrical resistivity imaging (ERI) is a geophysical technique for imaging sub-surface structures from electrical resistivity measurements made at the surface.

In electric resistivity imaging (ERI) electric currents are injected into the ground and the resulting potential differences are measured at the surface, yielding information about the distribution of electrical resistivity below the surface. Finally, this gives an indication of the lithological and structural variation of the subsoil (since resistivity depends on sediment porosity and pore water)


Process of Conducting a 2D ERI Survey:

The process of conducting a 2D ERI survey typically involves the following steps:

  • Survey Design: A geophysical expert designs the survey layout, considering factors such as target depth, resolution requirements, and survey area.
  • Instrument Setup: Specialized electrical resistivity equipment, including electrodes and data acquisition systems, are deployed on the survey site according to the designed layout.
  • Data Acquisition: Controlled electrical currents are injected into the ground, and voltage measurements are recorded using the electrode arrays. Multiple measurements are taken at different locations to ensure comprehensive coverage.
  • Data Processing and Interpretation: The acquired data undergoes sophisticated processing techniques, such as inversion algorithms, to generate 2D resistivity models. Geoscientists interpret the models to identify subsurface features and analyze the geological characteristics.

Advantages of 2D ERI Surveys:

Implementing 2D ERI surveys offers several key advantages over conventional subsurface exploration methods:

  • Comprehensive Subsurface Imaging: ERI surveys provide high-resolution images of subsurface features, allowing for a detailed understanding of the geological formations, water-bearing zones, and potential hazards.
  • Non-Destructive and Non-Intrusive: The technique does not require drilling or excavation, minimizing disturbance to the site and reducing costs and environmental impact.
  • Time and Cost Efficiency: 2D ERI surveys are relatively quick to conduct, enabling rapid data collection and analysis. The efficient workflow translates into cost savings and faster project timelines.
  • Versatility: The technique can be applied in various geological environments, making it suitable for a wide range of applications such as mineral exploration, groundwater studies, engineering investigations, and environmental assessments.
  • Preemptive Risk Mitigation: By accurately mapping subsurface features, potential risks such as sinkholes, landslides, and contaminated zones can be identified, enabling proactive risk management strategies.