Seismic Survey: Notes of major uses

 Seismic Survey

1. Suitable for mapping of layered sedimentary sequences

2. Widely used in search of oil and gas.

3. Small scale mapping of near surface sedimentary layers, location of water table, 

4. Site investigation of foundation conditions (including depth of bedrock). In engineering site investigation, Vp and Vs measurement for near surface layers allows direct calculation of Poisson's ratio and estimation of elastic moduli, which provides valuable information on in situ geotechnical properties.

5. Offshore geological surveys

Refraction

Reflection (most widely used geophysical technique)

Large/regional scale experiments for study of the entire crust or lithosphere. Estimation of depth of bedrock in foundation site investigation. In engineering purpose, derive relation between velocity and hardness of rock for quarrying operations, nature of landfill materials. Exploration of underground water in conjunction with resistivity methods (as there is a large difference in velocity of dry and wet sediments.)

Search of hydrocarbons, used in all stages of hydrocarbon exploration Vertical seismic profiling (VSP) is used at the stage of oil field development. High resolution studies of shallow geology High resolution reflection seismology is used in investigation of quaternary sedimentary sequences and detail mapping of concealed bedrock surfaces. Study of the entire continental crust and upper mantle.