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Shirmohammadi, F. (author), Draganov, D.S. (author), Ghose, R. (author)Seismic interferometry (SI) retrieves the Green function between two receiver locations using their recordings from a boundary of sources. When using sources and receivers only at the surface, the virtual-source gathers retrieved by SI contain pseudo-physical reflections as well as ghost (non-physical) reflections. These ghost reflections are...journal article 2024
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Ruan, J. (author), Ghose, R. (author), Mulder, W.A. (author)To investigate the physical processes behind induced seismicities due to, for example, production of hydrocarbons from a reservoir, most of the earlier studies performed geomechanical simulations on a simple reservoir geometry. The effect of fluid depletion is, in general, simulated for such a simple geometry. Neglecting the contribution of...conference paper 2023
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Kawasaki, Y. (author), Minato, S. (author), Ghose, R. (author)Bulk-density ( ρ) of soil is an important indicator of soil compaction and type. A knowledge of the spatial variability of in situ soil density is important in geotechnical engineering, hydrology and agriculture. Surface geophysical methods have so far shown limited success in providing an accurate and high-resolution image of 3-D soil...journal article 2023
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Ruan, J. (author), Ghose, R. (author), Mulder, W.A. (author)Intersecting faults are often ignored in the geomechanical simulation of induced seismicity. To investigate the effects of fault intersection and the resulting reservoir geometry on induced seismicity, caused, for instance, by gas extraction, we have developed 3D geomechanical models considering two intersecting normal faults and the...conference paper 2023
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Ghose, R. (author), Carvalho, João (author), Alves, Daniela V. (author), Santos, Luiz Alberto (author), Ressurreição, Ricardo (author), Alves, Paulo Henrique Bastos (author), Leote, Jaime (author)The Azambuja fault is a NNE trending structure located 50 km north of Lisbon, the capital and most populous city of Portugal. The fault has been considered as a possible source for the historical, large earthquakes. Understanding this fault is a priority in seismic hazard evaluation of this region. The fault has a clear morphological...journal article 2023
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Zuniga, Nelson Ricardo Coelho Flores (author), Draganov, D.S. (author), Ghose, R. (author)Using the critical angle information of a reflection event, it is possible to calculate several essential physical parameters that are key to reliable geological characterization of the subsurface. However, estimation of the critical angle usually requires several steps of seismic processing. For this reason, an approach which is capable of...journal article 2023
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Zuniga, Nelson Ricardo Coelho Flores (author), Draganov, D.S. (author), Ghose, R. (author)Using post-critical reflection data, it is possible to obtain useful information that allows more reliable geological characterization of the subsurface. However, the strong distortion caused by the phase shift in post-critical wavelets makes the use of post-critical reflections rather challenging. For this reason, an approach which is...journal article 2023
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- Ruan, J. (author), Masfara, La ODE Marzujriban (author), Ghose, R. (author), Mulder, W.A. (author) abstract 2022
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Ruan, J. (author), Masfara, La ODE Marzujriban (author), Ghose, R. (author), Mulder, W.A. (author)Geomechanical modelling is generally used to simulate the nucleation of induce d earthquakes in, for instance the Groningen gas field. We apply quasi static simulation to investigate the stress changes from gas production. When a fault reaches a critical state, dynamic simulation provides information on the dynamic rupture during ea rthqu ake...poster 2022
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Liu, J. (author), Draganov, D.S. (author), Ghose, R. (author)Seismic incoherent noise and waves scattered from objects in the crossline directions can cause 2D elastic full-waveform inversion (FWI) to produce artifacts in the resulting 2D models. We develop a complete workflow that can determine subsurface S-wave velocity (VS) models inverted from 2D near-surface seismic data more stably. We make use...journal article 2022
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Shirmohammadi, F. (author), Draganov, D.S. (author), Balestrini, F.I. (author), Ghose, R. (author)Seismic interferometry (SI) is a method that retrieves new seismic traces from the cross-correlation of existing traces, where one of the receivers acts as a virtual seismic source whose response is retrieved at other receivers. When using sources only at the surface, and the so-called one-sided illumination of the receivers occurs, we will...conference paper 2022
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Liu, J. (author), Ghose, R. (author), Draganov, D.S. (author)Traditional least-squares full-waveform inversion (FWI) suffers from severe local minima problems in case of the presence of strongly dispersive surface waves. Additionally, recorded wavefields are often characterized by amplitude errors due to varying source coupling and incorrect 3D-to-2D geometrical-spreading correction. Thus, least...journal article 2022
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Ruan, J. (author), Masfara, La ODE Marzujriban (author), Ghose, R. (author), Mulder, W.A. (author)Dynamic geomechanical modeling can generate the seismic wavefield caused by a fault rupture. In dynamic fault-rupture modeling, the source is considered to be finite, with a limited extent both in space and in time. This contrasts with the definition of a point source, which is generally assumed to explain the seismic wavefield caused by an...book chapter 2022
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Slob, E.C. (author), Draganov, D.S. (author), Eltayieb, M.F.M.I. (author), Drijkoningen, G.G. (author), Werthmüller, D. (author), Ghose, R. (author)Difficulties in detecting and characterising shallow objects close the surface with seismic shear waves are often problematic because of dominant surface waves. By sequencing a specific combination of two data driven processing steps followed by diffraction tomography can overcome these problems. Small scattering objects become visible in the...conference paper 2021
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Ruan, J. (author), Ghose, R. (author), Mulder, W.A. (author)Induced seismicity from a gas-producing region such as Groningen is believed to be caused by reservoir depletion due to long-term gas production. However, because of the complexity and uncertainty regarding the underground structure and composition, it is difficult to quantify the effect on induced seismicity due to gas production. Here we use...poster 2021
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Ruan, J. (author), Ghose, R. (author), Mulder, W.A. (author)Induced seismicity from a gas-producing region such as Groningen is believed to be caused by reservoir depletion due to long-term gas production. However, because of the complexity and uncertainty regarding the underground structure and composition, it is difficult to quantify the effect on induced seismicity due to gas production. Here we use...abstract 2021
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Minato, S. (author), Ghose, R. (author)When using waveform tomography to perform high-resolution imaging of a medium, it is vital to calculate the sensitivity in order to describe how well a model fits a given set of data and how the sensitivity changes with the spatial distribution of the heterogeneities. The traditional principle behind calculating the sensitivity—for detecting...journal article 2021
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Liu, J. (author), Draganov, D.S. (author), Ghose, R. (author), Bourgeois, Q. (author)Detecting small-size objects is a primary challenge at archaeological sites due to the high degree of heterogeneity present in the near surface. Although high-resolution reflection seismic imaging often delivers the target resolution of the subsurface in different near-surface settings, the standard processing for obtaining an image of the...journal article 2021
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Ruan, J. (author), Ghose, R. (author), Mulder, W.A. (author)Modelling dynamic rupture is essential to correctly describe the process of induced seismicity. Defmod, an open-source finite-element code featuring quasi-static loading, co-seismic volumetric strain, and dynamic rupture, is used to simulate the entire chain of induced seismicity, from pressure evolution due to fluid injection and extraction,...abstract 2020
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Minato, S. (author), Wapenaar, C.P.A. (author), Ghose, R. (author)To quantitatively image fractures with high resolution, we have developed an elastic least-squares migration (LSM) algorithm coupled with linear-slip theory, which accurately addresses seismic wave interaction with thin structures. We derive a linearized waveform inversion using the Born approximation to the boundary integral equation for...journal article 2020