A New Algorithm for the Seismo-Electrokinetic effect generated by different seismic waves and it’s application to shallow depths.

Summary

A new approach to modeling the seismoelectric (seismo-electrokinetic) effect is presented. It is based on the concept that at a specific time each location on the wave front that proceeds through the medium imparts equal pressure on the solid matrix and pore space. Consequently two fundamental equations contribute to the basis for the calculation of the electrokinetic effect (EKE): the first describes the relative displacement of particles in the sediment at the arrivals of the seismic wave and second, the transient streaming potential, induced in a pore, when the pressure pulse is applied to a cylindrical pore. To calculate the EKE on the surface the following are required: calculate the pressure gradient in a single pore caused by a seismic wave, the transfer from EKE arising in a single pore to the porous media, integrate the EKE signals all over the sediment space or layer and access the electrokinetic coefficients. A new algorithm has been developed. Being able to model field data mathematically shows the viability of this approach and allows the estimation of permeability of layers. To obtain a realistic geological and groundwater model test site, several geophysical methods were applied to a small area (shallow refraction seismic, DC resistivity, SP, FDEM, magnetic gradiometry). Comparing the EKE result modelled with the new algorithm with the above methods shows that the seismo-electrokinetic method can be successfully used for the exploration for ground water at shallow depths.

Key words::

• seismoelectric effect
• mathematical modeling
• pore
• permeability