- document
-
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
- document
-
Ruan, J. (author), Masfara, L.O.M. (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
- document
- Ruan, J. (author), Masfara, L.O.M. (author), Ghose, R. (author), Mulder, W.A. (author) abstract 2022
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
Balestrini, F.I. (author), Draganov, D.S. (author), Malehmir, Alireza (author), Marsden, Paul (author), Ghose, R. (author)In mineral exploration, new methods to improve the delineation of ore deposits at depth are in demand. For this purpose, increasing the signal-to-noise ratio through suitable data processing is an important requirement. Seismic reflection methods have proven to be useful to image mineral deposits. However, in most hard rock environments,...journal article 2020
- document
-
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
- document
-
Minato, S. (author), Ghose, R. (author), Wapenaar, C.P.A. (author)Single-well reflection imaging using sonic logging data successfully locates fine-scale structures around a borehole including fractures. In order to achieve accurate and quantitative estimation of fracture properties with high resolution, we propose to couple least-squares migration with linear slip theory. The proposed least-squares...conference paper 2019
- document
-
Minato, S. (author), Ghose, R. (author), Wapenaar, C.P.A. (author)Characterizing subsurface fractures is a key to developing hydrocarbon and geothermal fields, as well as providing fundamental information on fracture system relevant to regional seismotectonics. Seismic characterization of fractures has generally been based on the effective medium theory, which considers seismically invisible small fractures....conference paper 2019
- document
-
Minato, S. (author), Ghose, R. (author), Wapenaar, C.P.A. (author)Characterizing the mechanical and hydraulic properties of fractures is crucial in hydrocarbon and geothermal field development. Contrary to passive microseismic measurements, active seismic measurements using a borehole, e.g., VSP or sonic logging, have a potential to address aseismic fractures. However, there is a considerable scale gap between...conference paper 2019
- document
-
Kirichek, Alex (author), Chassagne, C. (author), Ghose, R. (author)4-electrode setups are usually used to measure the dielectric response (complex conductivity) of sandstones, as it is known that 2-electrode systems are sensitive to unwanted electrode polarization at low frequency. Moreover, electrode polarization (EP) occurs in the frequency range where the characteristic relaxation associated to the grain...journal article 2019
- document
-
Minato, S. (author), Ghose, R. (author)Time-lapse seismics has a wide range of application in different scales, from near-surface to resource exploration. Crosshole seismics is used to characterize fluid reservoirs and to obtain highly resolved rock/soil-dynamic parameters e.g., elastic moduli and Poisson ratio. Developments in distributed acoustic sensing shows the potential of...conference paper 2019