Seismoelectric imaging of the vadose zone of a sand aquifer

Abstract

We have acquired a [Formula: see text] seismoelectric section over an unconfined aquifer to demonstrate the effectiveness of interfacial signals at imaging interfaces in shallow sedimentary environments. The seismoelectric data were acquired by using a [Formula: see text] accelerated weight-drop source and a 24-channel seismoelectric recording system composed of grounded dipoles, preamplifiers, and seismographs. In the shot records, interfacial signals were remarkably clear; they arrived simultaneously at offsets as far as [Formula: see text] from the seismic source. The most prominent signal was generated at the water table at a depth of approximately [Formula: see text] and had peak amplitudes on the order of [Formula: see text]. A weaker response was generated at a shallower interface that is interpreted to be a water-retentive layer. The validity of these two laterally continuous events, and of other discontinuous events indicative of vadose-zone heterogeneity, is corroborated by the presence of reflections exhibiting similar characteristics in a ground-penetrating radar profile acquired along the same line.

Laboratory measurements and theoretical modeling of seismoelectric interface response and coseismic wave fields

“…[3][4][5][6][7] Furthermore, a wide range of field and laboratory validations of the coseismic field and the interface response was presented in the literature. [8][9][10][11][12][13][14][15][16][17][18][19][20][21] Several of these works compare either field measurements 15,17 or laboratory measurements 20 with a seismoelectric wave propagation model, corroborating that the coseismic and interface response fields are predicted by the theory.…”

Modelagem numérica do efeito sismoelétrico em meios 2D

“…No entanto, a dificuldade imposta pelo grande número de parâmetros dos quais depende o sinal sismoelétrico (parâmetros poroelásticos e os parâmetros associados ao coeficiente de acoplamento eletrocinético) impede o uso direto da ferramenta sismoelétrica para determinar tais parâmetros sob condições reais, apesar do sucesso de alguns trabalhos experimentais (Murty, 1985;Thompson & Gist, 1993;Butler et al, 1996;Mikhailov et al, 1997Mikhailov et al, e 2000Zhu et al, 1999;Garambois & Dietrich, 2001;Fourie, 2003;Zhu & Toksöz, 2003e 2005Haines, 2004;Dupuis et al, 2007;Strahser et al, 2007).…”

A review on electrokinetically induced seismo-electrics, electro-seismics, and seismo-magnetics for Earth sciences

“…A vibrator-source tested by Haines (2004) showed too much electrical noise to be used. Several records can be combined to improve the signal-to-noise ratio (Kepic and Rosid, 2004;Dupuis et al, 2007;Strahser et al, 2011). The triggering using the electric signal of the output of an accelerometer mounted on a hammer can generated electromagnetic noise.…”

“…The SEM advantageously in detecting zones of high fluid mobility and contrasts of physical parameters as porosity, geochemical fluids, permeability at depths from a few metres to a few hundred metres Dupuis and Butler, 2006;Dupuis et al, 2007Dupuis et al, , 2009Strahser et al, 2007Strahser et al, , 2011Haines et al, 2007a, b); for the characterization of permeable zones along a borehole (Mikhailov et al, 2000) and the groundwater exploration in a fractured rock aquifer (Fourie and Botha, 2001;Fourie et al, 2000). However, surface observations are difficult to use for the exploration of deep formations because of the low efficiency of the seismoelectric conversion and the attenuation within the formations.…”