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E.C. Slob

24 records found

Reflection seismology aims to estimate the Earth's subsurface elastic parameters for further investigation by geologists and engineers. This involves generating elastic waves using seismic sources and recording the Earth's response with receivers. The subsurface model is typicall ...

Time-lapse monitoring with virtual seismology

Applications of the Marchenko method for observing time-lapse changes in subsurface reservoirs

Monitoring time-lapse changes inside the subsurface is of great significance to many geotechnical applications, such as storage of gasses in underground geological formations. Minute differences in the seismic wavefield between an initial baseline and a subsequent monitor survey ...
Damages within asphalt have been interesting phenomena in asphalt engineering, the detection of which is significant for maintenance of road sections. This project focuses on cracks and delaminations. An attempt was made to filter radar image data with a method based on a VNA-ant ...
Motivated by environmental concern, the industry has been developing an alternative marine seismic source, in particular a marine vibrator. By spreading the emitted energy out over time, vibrator sources are perceived to be less intrusive to marine mammals. It is also believed th ...
As an alternative to the industry standard processing of total field data, a Basin-hopping inversion can be used. Another alternative is the use of vector field magnetometers, which can be processed with a Gauss-Newton inversion. Both the Basin-hopping and Guass-Newton inversion ...
In this thesis I conducted ground penetrating radar (GPR) and ground conductivity meter (GCM) surveys to detect the presence of simulated clandestine burials at the Amsterdam Research Initiative for Subsurface Taphonomy and Anthropology (ARISTA) test facility, and determine their ...

Forward modeling for electromagnetic subsea cable tracking

A better understanding of offshore wind turbine power cables

Failure of subsea wind turbine cables are the main cause for wind farm downtimes. Furthermore, 80% of insurance payouts to wind farms come from cable repairs and maintenance. Cable tracking is part of the wind farm cables maintenance scheme. Surveys are required for localisation ...
The magnetic method is one of the geophysical techniques that prevails in the detection and identification of Uneploaded Ordnance (UXO). Inversion of the magnetic data, allows us to recover the position and the magnetic dipole moment of the object. The typical use of a model is a ...
Clay has been used for many hundreds of years in building dikes. Their physical properties and thickness are essential for a dike to maintain its function. For the last fifteen years electromagnetic induction instruments (EMI) have been playing a growing role in mapping electroma ...
Geophysical monitoring is a popular tool in aquifer characterization and groundwater flow. To address this objective at groundwater extraction site ‘t Klooster, an ERT dataset was analyzed to identify groundwater flow patterns resulting from the injection of warm oxygenated water ...
The hazards of unexploded ordnance threaten the increasing marine construction activities nowadays, which increases the importance of unexploded ordnance detection. Research has shown that transient electromagnetic methods can successfully be used to detect unexploded ordnance on ...
The aim of this study is to look into the effect of water content in clays on the electrical conductivity as obtained from measurements of an frequency domain electromagnetic induction survey and a laboratory resistivity test. The laboratory test results are compared to theoretic ...
The multi-pole PML (MPML) is tested on models that simulate seismic waves traveling through the subsurface. Using a recursive integration technique a stretching function consisting of the sum of multiple stretching functions is implemented in the velocity-stress finite difference ...
The position of installed submarine power cables is often not accurately known for several reasons. The precise knowledge of the cable position is important for the maintenance process and necessitates the need for cable tracking systems. Current systems are in many cases impreci ...
Forensic investigations focused on determining clandestine buried weapons, narcotics or even homicide evidence, can be expensive, inefficient and depend greatly on prior information and the tools available. Geophysical tools have potential to improve these investigations, on the ...
Backward erosion piping is a dike failure mechanism. It is the internal erosion process by which sand is eroded away from underneath a dike or levee by seepage flow. This erosion process progresses in the direction opposite to the direction of seepage flow and forms a small pipe ...
One of the most crucial estimates retrieved from measured seismic reflection data is the subsurface image. The image provides detailed information of the subsurface of the Earth. Seismic reflection data consists of so-called primary and multiple reflections. Primary reflections a ...
Marchenko inversion is a new way to invert seismic or electromagnetic data recorded during geophysical surveys. The inversion method uses Marchenko theory. This is a recent development which enables the retrieval of Green's functions at any place in the subsurface. A non-recursiv ...
The Marchenko method is being developed to compute redatuming operators from the reflection response based on a new normalization option at the data level. These operators can be used to retrieve the two-way focusing functions in terms of pressure and velocity, respectively, with ...
The finite-element method can easily handle complicated geometries because of the application of unstructured meshes. Unlike the Cartesian grid used in the finite-difference method, the unstructured mesh can follow the sharp interfaces that separate two layers of different proper ...