Downhole nuclear magnetic resonance technology was applied in four boreholes intersecting glaciomarine sediments of the Ottawa Valley, Ontario. The study evaluated the ability of slim‐hole nuclear magnetic resonance tools to measure in situ volumetric water contents (porosities in saturated sediments) for geohazard and hydrogeological applications. The sediments are composed of clay‐ and silt‐sized

In this study, we undertake a renewed investigation of up‐bent reflections seen in seismic time sections from the Baltic Sea, Bay of Kiel. These warped reflections stretch over the entire vertical extent of the sections, from Permian to Quaternary strata, and underlie tunnel valleys. Previous studies interpreted these structures as anticlines explaining them together with adjacent faults and disrupted

Over the past 20 years, there has been growing interest in the use of the subsurface for water storage using shallow ponds, where water is infiltrated to the subsurface and subsequently groundwater is recovered from pumping wells. This scheme is designed as a surface‐managed aquifer recharge. Llobregat artificial recharge ponds are managed aquifer recharge systems located in alluvial aquifers near

A major problem for the freshwater supply of coastal regions is the intrusion of saltwater into aquifers. Due to extensive extraction of freshwater to suffice increasing drinking water demands and/or in periods of reduced groundwater recharge, the equilibrium state may be disturbed. The result is an upconing or movement of the fresh–saline groundwater interface, which reduces the local drinking water

In the past several decades, there has been considerable interest in groundwater–surface water interactions and their ability to regulate and cycle nutrients and pollutants. These interactions are spatially and temporally complex, but electrical resistivity imaging can be a useful tool for their characterization. Here, an electrical resistivity imaging monitoring array was installed laterally across

To improve risk assessment, control and treatment strategies of contaminated sites, we require accurate methods for monitoring solute transport and infiltration in the unsaturated zone. Highly spatio‐temporal heterogeneous infiltration during snowmelt increases the risk of contaminating the groundwater in areas where de‐icing chemicals are required for winter maintenance of roads and runways. The objective

In this paper, we discuss the necessity of quantifying and correcting seasonal 3D effects on 2D electrical resistivity tomography (ERT) data measured along the embankments of rivers or artificial canals. A permanent ERT monitoring system has been continuously operating along the levee of an irrigation canal in Mantua province, Italy, since September 2015. To evaluate the importance of 3D effects and

Electrical resistivity tomography is a technique widely used for the investigation of the structure and fluid dynamics of the shallow subsurface, particularly for hydro‐geophysical purposes, sometimes using cross‐borehole configurations. The results of electrical resistivity tomography inversion and their usefulness in solving hydrogeophysical problems, even though invariably limited by resolution

Migration is considered to be a key step in the data processing of the seismic advancement predictions of tunnels, and directly affects the final interpretations. Therefore, with the goal of addressing the limitations of the current acoustic reverse‐time migration (RTM) processes, as well as deepening the understanding of the interactions between different wave modes in traditional elastic reverse‐time

A novel traveltime tomographic approach is applied to anisotropic media, limited to 2D geometry for the moment. A general anisotropic Eikonal solver based on a discontinuous Galerkin method is combined with an efficient adjoint formulation for multiparameter least‐squares inversion. This new approach is tested considering synthetic crosshole Ground Penetrating Radar data in a configuration inspired

Wind turbines produce mechanical energy that can propagate to the ground and disturb sensitive measurements such as seismic recordings. The aim of the large‐scale experiment Seismic Monitoring And Research of wind Turbine Induced Emissions (SMARTIE1) at a single wind turbine in Pfinztal (SW Germany) is to understand how wind turbines emit seismic signals under different operating conditions and how

An unexpected surface subsidence in Mexico City on 19 May 2015 prompted a detailed geophysical investigation of the three‐dimensional structure of a collapsed‐soil mine located in a section of the Chapultepec Park in the vicinity of an artificial lake. As revealed from past geological explorations, the subsoil at the site consists of volcano‐sedimentary materials that were quarried in the mid‐20th

Several studies have explored the potential of electrical resistivity tomography to monitor changes in soil moisture associated with the root water uptake of different crops. Such studies usually use a set of limited below‐ground measurements throughout the growth season but are often unable to get a complete picture of the dynamics of the processes. With the development of high‐throughput phenotyping

To derive reliable electrical resistivity subsurface models using error‐weighted inversion schemes, a meaningful and correct error model is required. An over‐estimated error leads to a lack of resolution and reduced target detectability. Furthermore, biased data are easily overlooked and can lead to artefacts and significant miss‐interpretation. We carried out an electrical resistivity tomography survey

The use of surface wave testing for near‐surface engineering applications has increased in recent years. Typical surface wave analysis is based on the dispersion of surface waves in one‐dimensional layered models. One‐dimensional models are inappropriate for measurements at sites with appreciable lateral variability, a likely scenario in many engineering applications. Use of such models can subsequently

A new method is presented for the 3‐D forward modelling of the magnetic effects (induced magnetization) of a hexahedral (trilinear) prism using the Gauss–Legendre quadrature method. The 3‐D forward modelling provides an improved application to geological problems. The magnetic effect has been evaluated via the summation of the effects of the point dipole that fills the volume. The 3‐D volume is divided

In this work, we explore the use of biochar as a remediation agent, and the sensitivity of the spectral‐induced polarization method as a remediation monitoring aid. Biochar amended columns were fully saturated with industrial wastewater (olive oil mill waste) with very high concentration of phenols (∼2485 mg/L) and other substances. The biochar‐amended columns achieved very high removal rates of phenols

In this research, we have studied the capabilities and limitations of the transient electromagnetic sounding applied to investigate the structure and composition of the moraine deposits covering a crystalline basement. It has been experimentally demonstrated that using the ungrounded antennas one can not only determine the electrical resistivity of different layers in the alluvium deposits and map

Obtaining high‐quality ground penetrating radar (GPR) images in karst is difficult because materials resulting from the weathering of carbonate rocks might be electrically conductive. As a consequence, penetration depth and signal resolution might be greatly reduced due to attenuation. In addition, fractures and faults might cause a significant amount of electromagnetic wave scattering. We present

An interesting geological objective of quantitative interpretation of magnetic data is to find inverse models which can determine sharp geological interfaces below the surface. The stabilizing function in the Tikhonov parametric functional governs sparseness constraint in the recovered model. This paper introduces a novel stabilizer based on a sigmoid function which can provide non‐smooth models in

To improve the resolution of seismic data, it is important to accurately estimate the near‐surface quality factor, Q, which provides a measure of seismic wave attenuation. In view of the unique advantages provided by uphole surveys when investigating near‐surface structures, they are widely employed to estimate the near‐surface Q factor. However, the Q factor estimated using the traditional spectral

Guadalajara, Jalisco, is the second largest city in Mexico with around 4.5 million inhabitants. A high seismic hazard exists in the city due to forces produced by the interaction between the Rivera, Cocos and North American plates and the smaller Jalisco Block. Guadalajara is one of the largest cities built over pumice soil deposits. Furthermore, the near‐surface phreatic level causes a high susceptibility

A 3D geological model of the Torre‐Bembibre Carboniferous sub‐basin, a potential CO2 storage reservoir, is proposed here. The Torre‐Bembibre sub‐basin is part of the El Bierzo coal‐bearing Carboniferous basin located in the westernmost part of León province (NW Spain). It covers an area of about 150 km2. Carboniferous deposits (up to 1500 m of continental siliciclastics) are divided into nine intervals

We compare two Monte Carlo inversions that aim to solve some of the main problems of dispersion curve inversion: deriving reliable uncertainty appraisals, determining the optimal model parameterization and avoiding entrapment in local minima of the misfit function. The first method is a transdimensional Markov chain Monte Carlo that considers as unknowns the number of model parameters, that is the

Reprocessing of high‐resolution seismic reflection data over groundwater‐bearing glacial deposits near Heby, southeastern Sweden, improved the images of near‐surface structure at this site. Post‐stack time migration and pre‐stack depth migration were tested and compared to determine the improvements on imaging an undulating bedrock surface. The pre‐stack depth migration image displays better continuity

The Ripley Landslide is a small (0.04 km2), slow‐moving landslide in the Thompson River Valley, British Columbia, that is threatening the serviceability of two national railway lines. Slope failures in this area are having negative impacts on railway infrastructure, terrestrial and aquatic ecosystems, public safety, communities, local heritage and the economy. This is driving the need for monitoring

In this work, we describe an experiment concerning global–local full‐waveform inversion, carried out on a P‐wave seismic reflection profile that was acquired at Luni, an archaeological site in Italy. The global full‐waveform inversion makes use of a two‐grid genetic algorithm scheme and recorded refraction and diving waves, to build an initial velocity model of the subsurface. Two important pieces

To investigate transient dynamics of soil water redistribution during infiltration, we conducted horizontal borehole and surface ground penetrating radar measurements during a 4‐day infiltration experiment at the rhizontron facility in Selhausen, Germany. Zero‐offset ground penetrating radar profiling in horizontal boreholes was used to obtain soil water content information at specific depths (0.2

We apply seismic full waveform inversion to SH‐ and Love‐wave data for investigating the near‐surface lithology at an archaeological site. We evaluate the resolution of the applied full waveform inversion algorithm through ground truthing in the form of an excavation and sediment core studies. Thereby, we investigate the benefits of full waveform inversion in comparison with other established methods

Low‐frequency ground‐penetrating radar is known to be effective in the detection of geological disasters in open pits owing to its good detection depth, high resolution and portability. However, because of the lack of a shield layer and the poor anti‐interference capability, low‐frequency ground‐penetrating radar has certain limitations. A strong linear interference due to direct waves can result in

A study of the fracture systems in the basement of the Matatlan urban waste dump of Guadalajara City, near the western edge of the Rio Grande de Santiago canyon (southwestern Mexico), is reported. The Matatlan dumpsite was developed on top of andesitic and rhyolitic rocks. Measurements at outcrops indicated that N–S (0°–15° and 165°–180°), N45–90E and N105–135E fracture systems affect the basement

Geophysical methods are routinely applied for investigation of near surface in areas of infrastructure, water supply, artificial infiltration, farming, waste deposits, construction, etc. A new towed transient electromagnetic tool, called ‘tTEM’, provides rapid, efficient, high‐resolution imaging of subsurface hydrogeology, and can deliver densely spaced profiles of resistivity. These profiles can be

The impact of untreated sewage irrigation and waste disposal practices on groundwater is investigated by 3D joint inversion of radio magnetotelluric and electrical resistivity tomography data. In this case study, electrical resistivity tomography and radio magnetotelluric field measurements were carried out on several profiles near a waste disposal site which was irrigated with untreated sewage water