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Investigation · 04

Geophysical investigation

Seismic refraction and electrical resistivity imaging — reading lithology and depth to bedrock across a whole line before you commit to a single borehole.

Seismic · resistivity Methods
Soil-rock profiles Output
Snell’s Law Governed by

Seismic refraction

Wave velocity maps the strata.

A seismic survey provides information on shallow lithology along the surveyed lines and produces soil-rock profiles. The method depends on seismic waves travelling at different velocities through different soils and rocks, and refracting as they cross the boundary between one type or condition and another. From that you get general soil types and the approximate depth to strata boundaries or to bedrock.

Seismic refraction survey principle
Seismic refraction — wave paths across a strata boundary.

Electrical resistivity

Current finds the weak zone.

Resistivity imaging determines and estimates the overburden, the rock line and low-resistivity zones beneath the surface along the survey profile. We use the electrical current property to assess the character of subsurface material, on the principle that electric current will always pass through the weak zone.

Electrical resistivity imaging array laid out on site
Resistivity imaging array along a survey profile.

Applications

What it is used for

  • Rock competence for engineering applications
  • Depth to bedrock
  • Groundwater exploration
  • Correction of lateral, near-surface variations in seismic reflection surveys
  • Crystal structure and tectonics

Next step

Get a method and a rate.

Send us the survey line or the area to be covered and we will scope the spread.

Beantpreet Singh — Business Development +91 78883 13160 bd@rawelsinghco.in