Journal ArticleDOI
How velocity layering and steep dip affect cdp
TLDR
In this paper, normal moveout is used to distinguish primary from multiple reflections when the average velocity changes with depth, and the error appears to be controlled by the ratio of the standard deviation of the velocities within the section to the averaged velocity.Abstract:
Normal moveout may be used to distinguish primary from multiple reflections when the average velocity changes with depth. Approximate values of normal moveout may be found using an average velocity formula, but such values are always too large. The error appears to be controlled by the ratio of the standard deviation of the velocities within the section to the average velocity. Ray tracing provides normal moveout values which agree much better with observations. As a consequence of large dip, the reflections added by the CDP method do not represent identical areas of the dipping bed. However, if the various reflection zones lie on an inclined plane, they are added in‐phase and assume the time of a reflection from a point on the plane.read more
Citations
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Journal ArticleDOI
Migration and inversion of seismic data
TL;DR: A principal part of a migration‐inversion algorithm is the migration, and by making use of amplitudes versus offset, it is, in principle, possible to determine the three elastic parameters from compressional data.
Journal ArticleDOI
Velocity analysis for wide aperture seismic data
TL;DR: In this article, the authors proposed to transform the observational data to the domain of intercept or vertical delay time τ and horizontal ray parameter p, where headwave refractions are collapsed into points and both near vertical and wide angle reflections can be analyzed simultaneously to derive velocity depth information, even in the presence of velocity gradients or low velocity zones.
Book ChapterDOI
Velocity Determination from Seismic Reflection Data
TL;DR: In this paper, the authors used the maximum coherency stacking velocity through the r.m.s. velocity to determine the gross velocity distribution in the ground from CDP reflection data.
Journal ArticleDOI
Deep seismic crustal studies in Manitoba
D. H. Hall,Z. Hajnal +1 more
TL;DR: In this article, the results of 84 deep seismic sounding recordings scattered over an area of 250,000 km 2 (average spacing, 25 km) with each recording yielding up to 3 depth points for each interface mapped, are compiled on maps giving crustal thickness and depth to the transition between an upper and a lower crustal layer.
Journal ArticleDOI
Complex structure along a Mesozoic sea‐floor spreading ridge: BIRPS deep seismic reflection, Cape Verde abyssal plain
TL;DR: In this article, the British Institutions Reflection Profiling Syndicate (BIRPS) acquired closely spaced deepseismic-reflection profiles over the Early Cretaceous crust of the Cape Verde abyssal plain off West Africa.
References
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Journal ArticleDOI
Seismic velocities from surface measurements
TL;DR: In this paper, a simple but accurate formula is developed for the quick calculation of interval velocities from the known x2-T2 technique, which is obtained through a correlation of velocity with rock type and depth.
Journal ArticleDOI
Common Reflection Point Horizontal Data Stacking Techniques
TL;DR: In this article, a technique for multiple coverage of the subsurface is described whereby multiple coverage is obtained, and methods for attenuating multiple reflections with respect to primaries are discussed in considerable detail.
Journal ArticleDOI
A new data-processing technique for multiple attenuation exploiting differential normal moveout
TL;DR: In this paper, a new data processing technique is presented which utilizes optimum multichannel digital filtering in conjunction with common subsurface horizontal stacking for the efficient rejection of multiple reflections.
Journal ArticleDOI
Applications of the expanding reflection spread
TL;DR: In this paper, Dix's expanding reflection profile was described and procedures for the shooting and interpretation of these expanding reflection spreads were established, which made the interpretation and shooting of these spreading profiles simpler and more reliable.
Journal ArticleDOI
Seismic refraction with variable velocity
TL;DR: The results of an investigation of methods of interpreting and calculating the propagation of seismic waves with variable velocity in contrast to an assumed constant velocity is presented in this article, which can be applied to existing types of alluvia and similar geologic formations.