Seismology
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Processing of large offset data: experimental seismic line from Tenerife Field, Colombia
ABSTRACT: Exploration seismology provides the main source of information about the Earth’s subsurface, which in many cases can be presented as a simple model of horizontal or near-horizontal layers. After the seismic acquisition step, conventional seismic processing of reflection data provides an image of the subsurface by using information about the refle
Braz. J. Geol.. Publicado em: 08/03/2018
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2. Migration in depth pre-piling up using the cinematic attributes of the piling up for surface of common reflection / Migração em profundidade pré-empilhamento utilizando os atributos cinemáticos do empilhamento por superfície de reflexão comum
The Common-Reflection-Surface (CRS) stack is a new seismic processing method for simulating zero-offset (ZO) and common-offset (CO) sections. It is based on a second-order hyperbolic paraxial approximation of reflection traveltimes in the vicinity of a central ray. For ZO section simulation the central ray is a normal ray, while for CO section simulation the
Publicado em: 2007
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3. Définition et implémentation des corrections instrumentales de la mission spatiale CoRoT
CoRoT (Convection, Rotation and planetary Transits) is a space mission conceived to the stellar seismology and the search of extra solar planets. Both scientific programs are based on very high precision photometry and require long and uninterrupted observations. For the study of the stellar oscillations, the instrument must be able to measure periodic varia
Publicado em: 2007
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4. Amplitude preservation in wave equation migration / Preservação da amplitude na migração da equação da onda
Em meios homogêneos, o operador diferencial da equação da onda cheia pode ser substituído pelo produto de dois operadores diferenciais. Cada um destes operadores gera uma equação da onda de sentido único. As soluções destas equações descrevem a propagação de uma onda para baixo e uma para cima, respectivamente. Estas soluções possuem os mesmos
Publicado em: 2006
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5. Seismology and geodesy of the sun: Solar geodesy
Measurements of the elliptical figure of the sun made in 1966 are analyzed on an hourly basis. This analysis yields an improved measure of the previously found solar distortion, rotating rigidly with a sidereal period of 12.38±0.10 days. It also yields a set of residùals used to search for signals due to low-frequency solar oscillations.
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6. Ordered upwind methods for static Hamilton–Jacobi equations
We introduce a family of fast ordered upwind methods for approximating solutions to a wide class of static Hamilton–Jacobi equations with Dirichlet boundary conditions. Standard techniques often rely on iteration to converge to the solution of a discretized version of the partial differential equation. Our fast methods avoid iteration through a carefu
The National Academy of Sciences.
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7. Seismology and geodesy of the sun: Low-frequency oscillations
The hourly averages of the solar ellipticity measured from June 13 to Sept. 17, 1966, are analyzed for indications of solar oscillations with periods in excess of 2 hr ν < 0.5 hr-1. Nothing significant is found for frequencies ν > 0.1 hr-1 but for lower frequencies the power spectrum shows a very complex structure containing about 20 strong narrow peaks. T
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8. Irregular arrays and randomization
Although they lie at the conceptual core of a wide range of scientific questions, the notions of irregular or “random” arrangement and the process of randomization itself have never been unambiguously defined. Algorithmic implementation of these concepts requires a combinatorial, rather than a probability-theoretic, formulation. We introduce vector versi
The National Academy of Sciences.
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9. Initiation process of earthquakes and its implications for seismic hazard reduction strategy.
For the average citizen and the public, "earthquake prediction" means "short-term prediction," a prediction of a specific earthquake on a relatively short time scale. Such prediction must specify the time, place, and magnitude of the earthquake in question with sufficiently high reliability. For this type of prediction, one must rely on some short-term precu
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10. Structural geology of the Earth's interior*
Seismology is providing a more sharply focused picture of the Earth's internal structure that should lead to improved models of mantle dynamics. Lateral variations in seismic wave speeds have been documented in all major layers of the Earth external to its core, with horizontal scale lengths ranging from 10 to 104 km. These variations can be described in ter