We pursue accurate numerical techniques to obtain theoretical seismic waves for realistic three dimensional (3-D) Earth models using Spectral-Element Method. We have tried to solve forward problem, that is, to calculate synthetic seismic waveform for fully 3-D Earth model. We introduce a heterogeneous region at Earth's core-mantle boundary by combining a small, strongly anomalous region to a la...

The physical samples of natural gas hydrate were obtained first by drilling in permafrost region of Qilian Mountain of China in 2008. Permafrost area in Qilian Mt. is located in lower latitudes at high altitude, and the samples form in the Jurassic stratum under hard rock environment, rather than in unconsolidated soil layer. The environment of the Gas hydrate discovered is different from in th...

A limited seismic investigation of Ball Mountain Dam, an earthen dam near Jamaica, Vermont, was conducted using multiple seismic methods including multi-channel analysis of surface waves (MASW), refraction tomography, and vertical seismic profiling (VSP). The refraction and MASW data were efficiently collected in one survey using a towed land streamer containing vertical-displacement geophones ...

Minor faults, subsidence columns, coal tunnels and gob are very important in coal mining because they can cause flooding accidents, broken coal beds, added fissures, and gas accumulation. All of these factors will increase coal mining risk. In addition, minor faults also affect the design of roadways. In this article, we have achieved satisfactory results in identifying minor faults, subsidence...

We present a frequency-independent three-dimensional (3-D) compressional wave attenuation model (indicated by the reciprocal of quality factor Qp) for Kı̄lauea Volcano in Hawai‘i. We apply the simul2000 tomographic algorithm to the attenuation operator t∗ values for the inversion of Qp perturbations through a recent 3-D seismic velocity model and earthquake location catalog. The t∗ values are me...

Western gray whales (Eschrichtius robustus) aggregate off the northeastern coast of Sakhalin Island, Russia during summer-autumn to feed on benthic and near-benthic prey. During summer 2001, 3D seismic surveys were conducted during a six-week period in known gray whale foraging areas off Sakhalin Island. To test the hypothesis that the distribution of gray whales on the feeding ground would shi...

pore pressure could be estimated prior to drilling using seismic velocities. applying this approach, the final calculated pore pressure is highly affected by accuracy of the obtained velocity data. in order to generate an accurate velocity cube with proper resolution, velocities from well logs and post-stack 3-d seismic inversion are used along with stacking velocities from velocity analysis of...

this paper is devoted to compiling a site geology map for town of amiriyeh, from seismic macro-zonation point of view using geophysical methods of shallow seismic, down-hole seismic and resistivity surveys. in this map site geology has been classified based on shear wave velocity, according to the criteria for site geology classification offered in the iranian code of practice for seismic resis...

Seismic reservoir monitoring is a new technology that involves interpreting differences between different generations of 3-D seismic data in terms of changes in reservoir properties over time. A vast number of 3-D seismic surveys are repeated, in whole or in part, for reasons other than reservoir monitoring. In this paper, we cross-equalize two off-the-shelf migrated datacubes over a Gulf of Me...

This paper extends some authors’ previous approaches to models and methods based on fuzzy sets and fuzzy logic, for the seismic fragility updating and seismic damage evaluation, in their contributions to the IFIP 8 Conference (Krakow – 1998), SMiRT 16 (Washington DC – 2001) and SMiRT 18 (Beijing – 2005) Conferences. A short survey of such earlier and more recent proposals for applying fuzzy con...