ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00010.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractThe method ofFar Terrain Correctionsis described which permits contouring of terrain effects for distant topography; near terrain effects must be computed separately.The method is only slightly less accurate than standard graphical techniques and saves computing time. It is most useful in medium size surveys involving 100 to 2,000 observation points where the application of electronic computers is uneconomic.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb01996.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractA new method of treating three‐dimensional elastic wave problems is described by applying it to the most simple case of the reflection and transmission of arbitrary homogeneous spherical compressional waves at plane liquid‐liquid interfaces. The case of plane solid‐solid interfaces with equal shear velocities and equal densities can be treated under the same heading.The step‐response is obtained from the expressions for sinusoidal source excitation by a simple direct integration. The solutions for arbitrary source excitations are given in the usual way by the superposition integral. The solutions are proved by inserting them into the differential equations, followed by an application of the uniqueness theorem. The method is simple; all stages of establishing the solution (with the exception of the proof) are carried through in

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb01997.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractThe techniques of deconvolution have been formerly developped and tested on synthetic seismogramms.They are in the present study applied to field records or play backs.Three examples of the result of the deconvolution, i.e. of the reduction of filtering effects caused by the apparatus and the ground, are given.They show that the deconvolution increases the power of resolution and emphasizes thereby the resemblances as well as the differences between traces; consequently it enriches the correlation and improves the picking of the reflections which have a permanent enough character.Besides, it is shown that the comparison between deconvoluted traces and an impulsionnal synthetic seismogramm is, for the same reasons, more significant than between a field record and a filtered synthetic seismogramm.Finally, a section of deconvoluted traces shows that it is possible to obtain a valuable increase of resolution using one and the same inverse filter for a group of field records obtained with the same filter setting, even in locations where subsurface conditions are somewhat variable.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb01998.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractCertain travel time readings in shallow engineering seismology can be attributed to a seismic wave which has propagated through the air, but in which the energy has been transmitted into the ground before reaching the detector. Waveform evidence for this conclusion is presented, based upon the effects of altering the source conditions to delay the direct wave and of embedding the geophone in sound‐absorbent material. Erroneously large depths may be computed if these air wave readings are interpreted as readings produced by direct waves through the ground. Potential difficulty exists only if velocity in the near‐surface material is less than 330 meters/second (1100 feet/seco

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb01999.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractThe geometric description of wave fronts and ray paths has previously always started from the velocity distribution which has been chosen as simple as possible in order to be able to solve the integrals occurring in the basic equations. As the velocity is derived from the measured values of path and time, it is preferable to start from the path‐time function. There are exponential, parabolic and hyperbolic path‐time functions; the first and the second case correspond to the known linear and parabolic velocity functions. The hyperbolic case, on the other hand, has not yet been covered in literature. In the first two cases, two parameters–aandvo–can be chosen arbitrarily. In the hyperbolic case, we have 3 parameters (a, bandv)oat our disposal; this makes for a better approximation to actual conditions. A special advantage is seen also in the fact that the velocity does not become infinite with increasing depth but approaches a finit

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb02000.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Books reviewed in this article:Emmons, Allison, Stauffer, Thiel, Geology, Principles and Process, 5th EditionB. N. Ivakin, The Microstructure and Macrostructure of Elastic Waves

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb02001.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY