Presidential address     

Ivan I. Mueller 《Journal of Geodesy》1992,66(2):104-107

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Transient analysis of seismic core phases     

M. Landisman  S. Mueller  B. Bolt  M. Ewing 《Pure and Applied Geophysics》1962,52(1):41-52

Summary Speeded-up magnetic tape recordings of earthquake signals can be analyzed by means of an electronic sound spectrograph. The time-dependent spectrum of body waves obtained through transient analysis provides some insight into the physical properties of the earth's interior. In the short-period arrivals traveling through the outer core and inner core dispersion has been observed. A group velocity maximum has been found forP at periods between 1 and 2 seconds. The direct rayPand the surface reflected phasePP convey more energy than the arrivalsP ₂ andPcPP which, firstly, enter the outer core at incidence far from vertical, and secondly spend more time in the outer part of the fluid core.

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Zusammenfassung Magnetbandaufzeichnungen von Erdbebensignalen können, mit vervielfachter Geschwindigkeit wiedergegeben, mittels eines elektronischen Schallspektrographen analysiert werden. Das zeitabhängige Raumwellenspektrum, das man aus einer solchen Analyse nichtstationärer Vorgänge erhält, gibt einen gewissen Einblick in die physikalischen Eigenschaften des Erdinnern. So wurde im kurzperiodischen Anteil der Raumwellen, die durch den äusseren und inneren Erdkern gelaufen sind, Dispersion beobachtet. BeiP wurde im Periodenbereich zwischen 1 und 2 Sekunden ein Gruppengeschwindigkeitsmaximum gefunden. Der direkte StrahlP und die einmal an der Erdoberfläche reflektiertePP-Welle transportieren mehr Energie als die WellenphasenP ₂ undPcPP, die erstens in den äusseren Erdkern unter einem sehr grossen Inzidenzwinkel eindringen und zweitens eine längere Zeit benötigen, um den äusseren Teil des flüssigkeitsähnlichen Kerns zu durchlaufen.

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Lamont Geological Observatory Contribution No. 558.  相似文献   

Seismic response of precast concrete walls     

James M. Becker  Carlos Llorente  Peter Mueller 《地震工程与结构动力学》1980,8(6):545-564

Large panel precast concrete structures are built in major seismic regions throughout the world. The seismic behaviour of such structures is strongly dependent upon the characteristics of both the horizontal and vertical connections. The limiting behaviour of precast systems, however, is basically dependent upon the horizontal connection. The influence of horizontal connections can be studied in terms of the behaviour of a simple wall—a vertical stack of panels having only horizontal connections. This paper reports on research into the seismic behaviour of simple precast concrete walls. The research was carried out through the development of computer-based modelling techniques capable of including the typical behavioural characteristics associated with horizontal joints. The model assumes that all non-linear, inelastic behaviour is concentrated in the connection regions and that the precast panels remain linear elastic. This assumption allows the precast panels to be modelled as statically condensed ‘super-elements’ and the connection regions as interface elements. The above modelling technique allows for non-linear-inelastic seismic analysis that is capable of handling both rocking type motions throughout the height of the structure and slippage due to shear in the plane of the connection. A series of parametric studies are presented to illustrate the potential influence of rocking and slip on precast walls with both regular reinforcement and post-tensioning. These studies demonstrate the period elongation associated with the nonlinear-elastic rocking phenomenon. Shear slip is found to occur only when friction coefficients are extremely low or when the normal forces across the connections are low. This latter case occurs only in low buildings or in the upper floors of tall buildings. The paper concludes with a brief discussion of the design implications of these results. Particular attention is paid to the problems stemming from the force concentrations associated with rocking and shear slip.  相似文献   

The gross features of the lithosphere-asthenosphere system in Europe from seismic surface waves and body waves     

G. F. Panza  St. Mueller  G. Calcagnile 《Pure and Applied Geophysics》1980,118(2):1209-1213

Long-period recordings of dispersive Rayleigh waves along numerous station lines, or profiles, in Europe have for the first time permitted a uniform inversion of these observations based on a new method of phase velocity regionalization.Regional dispersion relations obtained by this method have then been subjected to a complete inversion procedure commonly known as the hedgehog method. The results are presented in a map outlining the thickness of the lower lithosphere (lid) and the shear (S) velocities in both the lid and the asthenosphere channel.A comparison of these results with the minimum compressional (P) wave velocities in the asthenosphere and their corresponding depths provides an estimate of theV _p /V _s ratio for the asthenosphere in the European area.Contribution No. 314, Institute of Geophysics, ETH-Zürich, Switzerland.  相似文献   

Detection of crustal motion using a spaceborne lasering system     

Muneendra Kumar  Ivan I. Mueller   《Tectonophysics》1979,52(1-4)

The spaceborne laser ranging (or lasering) system provides a method of precise positioning of a large number of points on the earth's surface in a short period of time. That is, a measure of the relative location of geodetic markers from a space platform can maintain horizontal and vertical control to 2–5 cm. At this level of control, small earth surface crustal motions should be detectable. Development of a model for the strain field can be constructed. Furthermore, the spaceborne lasering system can survey an area in a very short period of time (1–2 weeks) and resurvey the area as required.System design parameters are now being established by NASA for a possible test flight aboard the Shuttle in 1982. These include design specifications of economical corner cubes for ground retroreflectors, coupled with the evolution of engineering model to flight model development. If the experiment of the Shuttle proves successful, it is hoped to put the laser in a free flight satellite. This paper presents the results of a simulated analysis for this contingency.The system is conceived as an orbiting ranging device with a ground base grid of reflectors or transponders (spacing 1.0–30 km), which are projected to be of low cost (maintenance-free and unattended) and which will permit the saturation of a local area to obtain data useful in monitoring crustal movements. The test network includes 75 stations with roughly half of them situated on either side of the San Andreas fault. Critical study comparatively evaluates various observational schemes and statistically analyzes crustal motion recovery.The study considers laser radar as the main ranging system, pending final selection from many possible candidates. The satellite orbit is inclined at 110° and slightly eccentric (e = 0.04) with orbital altitudes varying from 370 to 930 km.  相似文献   

Improvement of inertial surveys through post-mission network adjustment and self-calibration     

John Hannah  Ivan I. Mueller 《Journal of Geodesy》1981,55(4):329-339

Present day inertial surveys are limited to single traverse runs in which the number of unknown system parameters to be determined are few, depending on the number of control points available along the traverse. Further, conventional inertial surveys are generally restricted to the determination of coordinates with no possibility for a rigorous post-mission adjustment of the observations. The consequence is the continued presence of systematic trends in the residuals, even after the use of error models such as those proposed by Ball, Gregerson or Kouba. Future work aiming at higher accuracies obviously requires more comprehensive models and rigorous adjustment procedures. These can be accomplished by the development of such error models and by the use of “area surveys”, instead of the single traverses, together with rigorous adjustment procedures suitable for the network of criss-crossing lines inertially surveyed. In such a network the cross-over points serve as constraints for the geodetic parameters (latitude, longitude, height, gravity anomaly, deflection components) and allow the addition of hardware and software related error parameters. Thus an opportunity is provided to effectively self-calibrate the system—a concept successfully used, for example, in photogrammetry or in satellite tracking. The number and the strength of such parameters depend on the number of control and cross-over points. The adjustment, of course, also provides the necessary statistical information on the adjusted parameters, such as their precision and the correlation between them. The presentation will describe current work at OSU in this area. Presented at the Second International Symposium on Inertial Technology for Surveying and Geodesy, Banff, Canada, June 1–5, 1981.  相似文献   

Inertial survey systems in the geodetic arsenal     

Ivan I. Mueller 《Journal of Geodesy》1981,55(4):272-285

After reviewing the overall goals of geodesy, the paper focuses on the unique properties of inertial survey systems in the geodetic arsenal: three-dimensionality; ability to determine relative positions and changes in the anomalous components of the earth’s gravity field; and independence of line-of-sight observations and the effects of refraction, both traditional antagonists in geodetic operations. Inertial survey systems, including field and office computational procedures, are briefly reviewed. Their short-comings are pointed out and certain remedies offered. Future possible improvements in hardware and software, as well as the development of hybrid systems (e.g., with gravity gradiometers), are discussed. “Apart from the refinement of existing techniques through the use of computers and the introduction of electromagnetic and optical distance measurement devices, instrumental research and development has been conducted by scientists and engineers outside the geodetic profession. This separateness of geodetic instrument research and development is seen as a deficiency by some, because of the reduced interaction between measurement techniques and the problems to which they apply. However, geodesy does not seem extraordinarily different from other environmentally oriented sciences in this respect and certainly has been quick to adopt new techniques once the benefits become evident.” (NAS 1978, p. 6) From the Keynote Address presented at Second International Symposium on Inertial Technology for Surveying and Geodesy, June 1–5, 1981, Banff, Alberta, Canada.  相似文献   

Absolute gravity measurements in Switzerland: Definition of a base network for geodynamic investigations and for the Swiss fundamental gravity net     

I. Marson  H. -G. Kahle  F. Chaperon  St. Mueller  F. Alasia 《Journal of Geodesy》1981,55(3):203-217

Summary Results of two absolute gravity surveys performed in Switzerland between 1978 and 1979 are presented and discussed in the framework of the uplift history of the Swiss Alps. Five absolute stations have been established as a contribution to the Swiss fundamental gravity net as well as to geodynamic investigations on the Alpine uplift. Two sites (Interlaken—Jungfraujoch) form the end points of a calibration line for field gravimeters. The gravity range of this line amounts to 605×10⁻⁵ ms⁻² (=605 mgal). It can be traversed in a relatively short time interval of less than 3 hours. Two other sites (Brig and Chur) are located in the area of the most negative gravity anomalies and highest uplift rates encountered in Switzerland. They serve as reference stations for a more extended gravity net for studying non—periodic secular gravity variations associated with the Alpine uplift. Institut für Geod?sie und Photogrammetrie, ETH-Zürich, Separata No. 13. Institut für Geophysik, ETH-Zürich, Contribution No. 333.  相似文献   

Orientation of the Earth by numerical integration     

F. A. Fajemirokun  F. D. Hotter  I. Mueller 《Journal of Geodesy》1976,50(2):109-129

Recent research in the department has involved determining the value of lunar observations in the determination of geodetic and selenodetic control. A fundamental consideration in the research is the determination of the orientation of the Earth in the celestial coordinate system. Classical reductions for precession and nutation can be expected to be consistent with the present day observations, however, corrections to the classical theory are difficult to model due to the large number of coefficients involved. Consequently, a portion of the research has been devoted to numerically integrating the Eulerian equations of motion for a rigid Earth and considering the six initial conditions of the integration as unknowns. Comparison of the three adjusted Eulerian angles from the numerical integration over 1000 daysindicates agreement with classical theory to within 0.003 seconds ofarc. This work was performed under NASA Contract No. NAS 9-13093. Presented at the International Symposium on Computational Methods in Geometrical Geodesy, Oxford, September 2–8, 1973.  相似文献   

Global satellite triangulation and trilateration     

I. I. Mueller 《Journal of Geodesy》1968,42(1):53-71

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