#Geomodel cube full#

They often combine a short-spread towed-streamer acquisition with sparse 4C (four-component) OBS (ocean bottom seismometer) deployments. Combining these methods with the up-to-date seismic acquisition techniques available nowadays should allow for regional-scale seismic imaging of continental margins at sub-wavelength spatial resolution (typically few hundred metres) ( Morgan etВ al., 2013).Дuring the last decades, a vast majority of deep-crustal seismic experiments carried out in academia were performed in two dimensions (namely, along profiles), mainly due to the financial cost of such experiments and the lack of suitable equipments.

#Geomodel cube full#

et al., 2017, 2019 Sambolian etВ al., 2019), wavefront tomography ( Bauer etВ al., 2017), finite-frequency travel time tomography ( Mercerat and Nolet, 2013 Zelt and Chen, 2016), wave equation tomography ( Luo and Schuster, 1991 Tong etВ al., 2014), and full waveform inversion (FWI) ( Tarantola, 1984 Mora, 1988 Pratt etВ al., 1996) shall be examined against large-scale numerical problems and complex synthetic datasets generated in an ultra-long-offset configuration. Among them, velocity reconstruction methods including first-arrival travel time tomography (FAT) ( Zelt and Barton, 1998), reflection tomography ( Bishop etВ al., 1985 Farra and Madariaga, 1988), joint refraction and reflection tomography ( Korenaga etВ al., 2000 MelГ©ndez etВ al., 2015), slope tomography ( Billette etВ al., 1998 LambarГ©, 2008 Tavakoli F.

In the context of this study, by seismic imaging we understand the broad range of procedures for estimating the earth's rock parameters from seismic data вЂ“ including travel time tomography, migration-based velocity analysis, ray-based and reverse-time pre-stack depth migration, and full waveform inversion. To meet this challenge, it becomes crucial to design numerical models and related synthetic experiments further promoting a new generation of crustal-scale seismic surveys.ДЄlong with the design of new acquisition settings, a quest for high-resolution reconstruction requires us to assess the feasibility of the leading-edge seismic imaging techniques and develop their necessary adaptations to the new acquisition specifications. This deep target reconstruction is typically beyond the range of the streamer-based data acquisition due to the limited length of the streamer cable ( в€ј6вЂ‰km). To make a step change in our understanding of the geodynamical processes that shape the earth's crust, we need to improve our ability to build 3D high-resolution multi-parameter models of geological targets at the regional scale. This benchmark model is intended to help to optimize the design of next-generation 3D academic surveys вЂ“ in particular, but not only, long-offset OBS experiments вЂ“ to mitigate the acquisition footprint during high-resolution imaging of the deep crust. Various wavefield simulations that we present clearly reflect in the seismograms the structural complexity of the model and the footprint of different physical approximations. We describe the workflow designed to implement all the model ingredients including 2D structural segments, their projection into the third dimension, stochastic components, and physical parameterization. The size of the model raises significant high-performance computing challenges to tackle large-scale forward propagation simulations and related inverse problems. It is defined in the form of a uniform Cartesian grid containing в€ј33.6e9 degrees of freedom for a grid interval of 25вЂ‰m. The 175 km Г— 100 km Г— 30 km model integrates complex geological structures with a viscoelastic isotropic parameterization.

Here, we introduce GO_3D_OBS вЂ“ a 3D high-resolution geomodel representing a subduction zone, inspired by the geology of the Nankai Trough. The deficiency of such models prompts us to build one and release it freely to the geophysical community. To assess and minimize the acquisition footprint in high-resolution imaging process such as full waveform inversion, realistic crustal-scale benchmark models are clearly required. In marine environments, controlled-source seismic surveys at a regional scale are typically carried out with sparse arrays of ocean bottom seismometers (OBSs), which provide incomplete and down-sampled subsurface illumination. One key to address this challenge is the joint development of new seismic acquisition systems and leading-edge processing techniques. Detailed reconstruction of deep crustal targets by seismic methods remains a long-standing challenge.