In the framework of Deep Electromagnetic Sounding for Mineral EXploration (DESMEX) project, we carried out multiple geophysical surveys from regional to local scales in a former mining area state Thuringia, Germany. We prove applicability newly developed semi-airborne electromagnetic (EM) systems mineral exploration by cross-validating inversion results with those established airborne and ground-based investigation techniques. addition, supporting petrophysical geological information our...

This study investigates the presence and spatial extent of saline water seawater intrusion in Subiya Peninsula, Kuwait, a region designated for establishment new Silk City. We collected transient electromagnetic (TEM) data at 63 stations using coincident loop setup on regional, as well local, scale. The were analyzed through conventional 1D inversion techniques, including Occam Levenberg–Marquardt methods, to create detailed resistivity models subsurface. Our findings indicate significant...

Over the last two decades, controlled source (CS) electromagnetic (EM) methods using an extended frequency range from 1-1000 kHz have been developed. Controlled sources complement Radio-magnetotellurics (RMT) method by providing a wider range, greater depth of investigation and more stable responses. In addition, they remain operational even without radio antennas in vicinity measurement area. While initially CS-/RMT was originally considered only far-field conditions, it has recently to...

There is a clear demand to increase detection depths in the context of raw material exploration programs. Semi-airborne electromagnetic (semi-AEM) methods can address these demands by combining advantages powerful transmitters deployed on ground with efficient helicopter-borne mapping magnetic field response air. The penetration depth exceed those classic airborne EM systems because low frequencies and large transmitter-receiver offsets be realized practice. A novel system has been developed...

The transition toward renewable energies demands a secure supply of critical raw materials and requires efficient noninvasive methods for deep earth resource exploration. novel, electromagnetic (EM) sounding the mineral exploration semi-airborne EM (semi-AEM) concept aims at resources down to depth 1 km. Here, we evaluate large-scale semi-AEM study in graphite mining district eastern Bavaria, Germany. derived 3D model is based on approximately 70,000 complex-valued data points recorded using...

We have developed a novel semiairborne frequency-domain electromagnetic (EM) system and successfully tested it within the DESMEX project. The approach relies on fact that part of is positioned ground rest airborne. This allows us to take advantage airborne techniques. In particular, high-moment transmitter can be installed earth’s surface, which enables inject induce strong EM fields in subsurface. Moreover, galvanic coupling possible, an if additional stations are deployed. receivers allow...

Water-covered areas may lead to gaps in surface electromagnetic surveys, causing reduced resolution and, as a consequence, increased uncertainty derived subsurface models. We have evaluated boat-towed floating central loop time-domain technique that mitigates this problem. It facilitates obtaining data with spatial sampling density, which is rarely possible standard instrumentation on land, and it only requires moderate logistical effort. A unique field study shallow volcanic lake...

ABSTRACT In the framework of Deep Electromagnetic Soundings for Mineral Exploration project, we conducted ground‐based long‐offset transient‐electromagnetic measurements in a former mining area eastern Thuringia, Germany. The large‐scale survey resulted an extensive dataset acquired with multiple high‐power transmitters and high number electric magnetic field receivers. recorded data exhibit quality over several decades time orders magnitude. Although obtained subsurface models indicate...

ABSTRACT The Eastern Mediterranean has been used as a passageway for human migration from Africa to the Middle East, Balkans and Europe. Azraq basin in eastern desert of Jordan major spot settlements since middle Pleistocene. former lake centre developed hyper‐saline alluvial mudflat, Qa’ Al Azraq. In mudflat thick sequences sediments are deposited. Such sediment successions promising archives reconstructing paleoclimate. order identify geological structures derive suitable borehole...

SUMMARY Central loop transient electromagnetic (TEM) data are often interpreted by conventional 1-D or quasi-2-D inversion techniques. For example, the lateral constrained (LCI) is a powerful technique for quick interpretation of central TEM data, and can produce spatially consistent resistivity images profile assuming spatial correlation between adjacent model parameters. Such techniques very in cases multidimensional effects small negligible. However, inverse solution LCI methods strongly...

Galvanic transmitter-receiver arrays commonly are used in marine controlled-source electromagnetic (CSEM) exploration of electrically resistive targets such as hydrocarbons, gas hydrates, etc. These utilize vertical electric currents and, a result, expected to provide better resolving capability for exploring subhorizontal structures than including horizontal coils. If, however, subseafloor target is located within transition zone at distances up few kilometers from the shoreline, 2D...

Transient electromagnetics (TEM) is a well-established method for mineral, groundwater, and geothermal exploration. Superconducting quantum interference device (SQUID)-based magnetic-field receivers used TEM have quantitative advantages higher sensitivity compared with commonly induction coils. Special applications are deep soundings target depths [Formula: see text] settings conductive overburden. However, SQUIDs rarely been applied measurements in environments significant anthropogenic...

SUMMARY Electrical anisotropy of formations has been long recognized by field and laboratory evidence. However, most interpretations long-offset transient electromagnetic (LOTEM) data are based on the assumption an electrical isotropic earth. Neglecting may cause severe misleading in regions with strong anisotropy. During a large scale LOTEM survey former mining area Eastern Germany, was acquired over black shale formations. These shales expected to produce pronounced bulk Here, we...

SUMMARY Joint inversion of multiple geophysical data sets with complementary information content can significantly reduce the non-uniqueness inherent to each individual set and, therefore, improve subsurface characterization. Gradient-based joint methods depend on choice model regularization and usually produce one single optimal model, rely linearization estimate parameter uncertainty. However, a quantitative evaluation uncertainty derived parameters is crucial for reliable interpretation....

SUMMARY Induced polarization (IP) effects can significantly affect and superimpose the inductive earth response, leading to heavily distorted data and, if overlooked, false geological interpretation. In this paper, we implemented Levenberg–Marquardt (LM) very fast simulated annealing (VFSA) algorithms recover IP from central loop transient electromagnetic (TEM) data. To incorporate effect in TEM used Cole–Cole parametrization, maximum phase angle (MPA), imaginary conductivity (MIC) Jeffrey...

Abstract Geophysical techniques have become increasingly crucial for characterizing landfills, offering noninvasive methods subsurface exploration and contamination assessment. In this study, an integrated geophysical approach—utilizing magnetic, electrical resistivity tomography (ERT), transient electromagnetic (TEM) surveys—was employed to characterize the Weidenpesch landfill in Cologne, Germany assess potential groundwater contamination. The results from these were consistent,...

ABSTRACT We present a simple and feasible approach to analyse identify two‐dimensional effects in central loop transient electromagnetic sounding data the correspondingly derived quasi conductivity models. The proposed strategy is particularly useful minimising interpretation errors. It based on calculation of semi‐synthetic tipper at each for observational time point. from measured vertical component induced voltage synthetically calculated horizontal component. computationally inexpensive...

Summary A novel semi-airborne frequency domain system is developed within the DESMEX project. The designed to achieve a penetration depth of about 1km with an areal coverage 6×6km2 per source installation on ground. Here, we report first results achieved new system. Horizontal electric dipole transmitters were used inject time-varying electrical currents into ground, and both three-axis induction coil set up (Metronix MFS-11e) fluxgate (Bartington MAG-03) installed helicopter-towed platform....

SUMMARY Various electromagnetic (EM) techniques have been developed for exploring natural resources. The novel frequency-domain semi-airborne controlled source (semi-AEM) method takes advantages of both ground and airborne techniques. It combines ground-based high-power electrical dipole sources with large-scale spatially densely covered magnetic fields measured via receivers. can survey the subsurface down to approximately 1000 m is particularly sensitive towards conductive bodies (e.g....

The classical radio-magnetotelluric (RMT) method is nowadays routinely applied to various environmental, engineering, and exploration problems. technique uses radio transmitters broadcasting in the frequency range of 10 kHz 1 MHz, measurements are carried out far field. well-known disadvantages RMT a lack robust remote areas; absence below kHz, which limits penetration depth; possible low signal-to-noise ratio. To overcome these difficulties, controlled sources can be used (controlled-source...

ABSTRACT The impact of untreated sewage irrigation and waste disposal practices on groundwater is investigated by 3D joint inversion radio magnetotelluric electrical resistivity tomography data. In this case study, field measurements were carried out several profiles near a site which was irrigated with water for agriculture purpose. addition, out, far away from the site, to derive uncontaminated geology. data analysed earlier using 2D techniques. However, data, assumptions about strike...