Showing papers in "Journal of Applied Geophysics in 2008"

TL;DR: In this article, reference coil-based noise cancellation and integrated FID imaging are used to increase the effective signal to noise ratios by an order of magnitude or more, which enables multi-coil surface NMR to produce useful and reliable images when the post-averaged SNR is less than 1.

TL;DR: In this article, the authors used time-lapse inversion to focus the variation over time and suppress artefacts due to the resistivity structure of Hallby dam, and found that increasing long term resistivity has been noticed in a particular zone in the left embankment.

TL;DR: In this paper, the 1D laterally constrained inversion (1D-LCI) algorithm is used to invert continuously sampled synthetic 2D TEM data sets with 3D near-surface resistivity variation.

TL;DR: In this article, the results of a variety of laboratory NMR and Magnetic Resonance Sounding (MRS) experiments are compared and discussed with respect to their applicability in MRS, and mean calibration factors are introduced for a data-base-calibrated estimation of hydraulic conductivity when no onsite calibration of MRS is available.

TL;DR: A geophysical survey including electrical resistivity tomography and seismic refraction tomography (SRT) was carried out to study a landslide site in the Altindag district of Izmir city, western Turkey.

TL;DR: In this article, the effect of magnetite concentration and grain size on proton nuclear magnetic resonance (NMR) relaxation rates of sand mixtures and to determine the dominant mechanism by which relaxation occurs was investigated.

TL;DR: In this article, a very low frequency-electromagnetic (VLF-EM) survey was carried out in two sites of domestic waste of old and recent landfills.

TL;DR: In this article, a 3D electrical resistivity tomography (ERT) scan was conducted in order to resolve the interpretation problems of ground-penetrating radar (GPR) data.

TL;DR: In this article, a singular value decomposition (SVD) of the MRS forward operator is used to derive the model resolution matrix including regularization parameters, including noise conditions.

TL;DR: In this article, fifteen magnetic resonance soundings (MRS) were carried out in December 2005 in the vicinity of wells and boreholes to improve the knowledge of the regionally important Continental Terminal 3 (CT3) aquifer in south-western Niger, and the MRS-determined parameters were then used to estimate the rates of groundwater recharge.

TL;DR: In this article, the authors used magnetic resonance soundings (MRS) for groundwater exploration and aquifer characterization, and demonstrated that the resistivities derived from MRS are comparable to those from conventional geoelectric methods such as DC resistivity and transient electromagnetic.

TL;DR: Aeromagnetic (AM) and Landsat Thematic Mapper (TM) data from the south-central Zimbabwe Craton have been processed for the purpose of regional structural mapping and thereby to develop strategic models for groundwater exploration in hard-rock areas.

TL;DR: In this article, the electrical resistivity tomography (ERT) was used to achieve a better understanding of the subsurface geoelectric structure at sinkhole development sites, taking into account that electric parameters (such as resistivity or conductivity) are very sensitive to formation properties and their variations in time.

TL;DR: In this paper, the authors proposed a new methodology for estimating hydraulic transmissivity using Magnetic Resonance Sounding (MRS) measurements, based on empiric relationships of the permeability with a factor F which is calculated with NMR parameters measured at laboratory scale.

TL;DR: In this article, an interactive transparent 3D visualisation of the 2D ground-penetrating-radar (GPR) profiles to determine changes in layer thickness and discontinuities is presented.

TL;DR: In this paper, a multi-objective evolutionary algorithm (MOEA) is proposed to improve the reconstruction of subsurface structure by exploiting the complementary information attainable by refraction seismics and surface-wave dispersion and by overcoming the problems related to nonuniqueness of the solution (surface waves and refraction seismic) and hidden layers (refraction).

TL;DR: The Picillo Farm, EPA Superfund Site, in western Rhode Island was an unauthorized disposal site of hazardous organic chemicals as discussed by the authors, and the electrical characteristics of both plumes were studied.

TL;DR: In this article, the authors proposed a new methodology to mitigate the blast-induced ground vibrations, which does not consider any blast parameters such as explosive types and amounts, blast-geometry, blasthole design, hole-depth/diameter, etc., except time-delays.

TL;DR: In this paper, the authors investigated the influence of the uncertainty in conductivity distribution provided by transient electromagnetic measurements (TEM) on magnetic resonance sounding (MRS) results and found that the uncertainty has an insignificant effect on MRS.

TL;DR: In this paper, the authors investigated the use of electrical resistivity tomography (ERT) as a technique for spatializing resistivity in a non-destructive manner in order to improve knowledge of relevant hydrological processes.

TL;DR: In this article, the most prominent magnetic, ductile signatures formed during the Svecofennian Orogeny (1900-1800 ǫ) resulting in elastic, curved, continuous magnetic patterns.

TL;DR: In this paper, the horizontal resolution of a pair of synthetic traces is analyzed and the trade-off between receiver spacing and accuracy of the inverted S-wave velocity is discussed, and a scheme is presented to generate a pseudo-2D Swave velocity section with high horizontal resolution using multichannel records by inverting high-frequency surface-wave dispersion curves calculated through cross-correlation combined with a phase-shift scanning method.

TL;DR: Magnetic Resonance Sounding (MRS) has been successfully tested for detecting groundwater in two areas in southern Sweden as discussed by the authors, and the results indicated aquifers that are not only hosted in soft sediment materials (moraine, sand, and mixed materials), but also hosted in basement rocks.

TL;DR: In this paper, 14 shallow seismic refraction profiles were conducted in Wadi Wardan, northeast Gulf of Suez, Sinai to delineate some of the shallow soil engineering characteristics for construction purposes.

TL;DR: In this paper, a MRS-TDEM combined geophysical survey was conducted to measure the applicability and the contribution of MRS to running drilling programs in the Danish context, and the results clearly suggest optimal locations for water supply boreholes within subsurface structures with homogeneous resistivity conditions mapped by TDEM.

TL;DR: In this paper, a numerical simulation experiment was applied to explore the potential and limitations of the inversion of the TEM response to a uniform half-space with a complex frequency-dependent conductivity described by the Cole-Cole model.

TL;DR: In this paper, a code for 3D resistivity modeling and inversion of vertical electrical soundings has been developed based on the finite element technique and regularization method, which is applied to experimental data set constituted by 35 Schlumberger soundings collected near the Cairo city in order to study the subsurface resistivity distribution.

TL;DR: In this paper, the authors provided a frame work for the characterization and mapping of subsurface channels for water seepage in the vicinity of dams using seismic refraction data.

TL;DR: In this article, 1 H 2D NMR relaxometry and PFG NMR diffusometry were used to characterize the pore space of karstified limestones and dolostones.

TL;DR: In this article, a scaled laboratory experiment was performed to validate if a thin resistive layer buried in conductive media can be remotely detected by using electric dipoles as sources and receivers.