摘要:

AbstractAccording to a study of seismic velocities in the Alpine Foreland of Eastern Switzerland, the initial velocity is rather high in comparison with other Tertiary basins and shows an exceptionally high increase rate. When analysing the average and the interval velocities, especially of Tertiary strata, and when comparing them with velocities of strata of the same age and a very similar facies of the Northern Rheintalgraben, it has been found that the increase of velocity is closely related to the distance to the Subalpine Molasse. The conclusion is that the velocity of the Tertiary strata is strongly influenced by the folding pressure of the Subalpine Molasse or of the Alps. The same method has been applied to a relatively large number of wells in the area of the “German Molasse”. Not only the results in Eastern Switzerland have been confirmed, but also it has been proved that the diagenesis of the Tertiary strata and, hence, their velocities are influenced only partially by the specific depth of the basin. Velocities increase towards the Folded Molasse or the Alps. Consequently they depend on lateral folding pressure, which decreases from west to east with the increasing width of the basin. The tertiary strata of the basin have been affected by lateral folding pressurefrom south to north. However, structures with lateral compression have not been discovered yet in the German Alpine Forel

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1969.tb02075.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe tools used in digital processsing have received little application, to date, to refraction seismic.It seems however that some problems encountered in the analysis of refraction records could be solved through techniques which are of common use in processing of reflection seismic data (correlation, stacking, f and k filtering).The experiments made with some of these techniques revealed the possibility of a more complete refraction record analysis, allowing the study of later arrivals.The interpretation of these records could also, to a fairly large extent, be automated by means of digital processing.While recording, some care ought to be taken to allow identification and interpretation by digital processing of as many events as possible. However, the results shown here have been obtained from fairly old analog records, for which no particular care had been taken, which makes it possible to complete and revise the interpretation of previous studies using the same processing techniques.Long line refraction shooting is justified for marine surveys in some areas, particularly where reflection is disturbed by singing; improvements in analysis and interpretation would therefore prove very useful for a faster and more thorough interpretation.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1969.tb02076.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractIn the case of simple time series it is shown that prediction operators can be considered as deconvolution operators which are easily obtained.These operators possess the special feature of having a minimum phase, and their spectrum modulus represents, with a good dynamic range, the reciprocal of the square root of the modulus of the original autocorrelation spectrum.A generalization of the simple time series theory to the functions of two independent variables is possible in as much as, on a given section, the application of the multiple time series method enables the function of time and distance variables to have well‐defined statistical properties; it is necessary, in particular, that the processes involved are stationary with respect to the two independent variables.In the case of multiple time series the application of the Prediction Theory permits greater uniformity of the traces because it enhances the events which show a good correlation between traces and, on the other hand, tends to minimize the random events which cannot be correlated between traces. The signal‐to‐noise ratio is thus increased to a great e

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1969.tb02077.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractIn a paper by Koefoed and Kegge (1968), which was based on previous work of Wesley (1958), the electrical current pattern has been derived that is induced by an oscillating magnetic dipole in a semi‐infinite thin plate of infinitesimal resistivity.In the present paper, the range of validity of the assumptions, on which the work of Wesley is based, is subjected to a theoretical analysis. It is found that the decisive factor for the validity of Wesley's derivation is the quotient of the square of the penetration depth of the electrical current over the product of the thickness of the plate and a distance that is indicative of the size of the current loops in the plate. Wesley's derivation is shown to be valid only when this factor is negligible. It is also shown that in this condition the imaginary component of the anomaly must be negligible.Model experiments are described in which the electrical current pattern is studied also in the range in which the derivation of Wesley is not valid. The procedure used in these model experiments was to measure the tangential component of the magnetic field strength very close to the metal plate that simulated the conductive dyke.In order to express the results of the measurements in terms of the imaginary to real ratio, these results are compared with an interpretation graph for field measurements that was published by Hedström and Parasnis (1958). It is found that the current pattern in the plate is essentially the same as that which follows from Wesley's derivation, provided that the imaginary to real ratio is less than one third. The measurements do not permit to draw conclusions regarding the current pattern in the plate in conditions that correspond to larger values of the imaginary to real rat

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1969.tb02078.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1969.tb02079.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY