ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 115 (1977), S. 675-692 
    ISSN: 1420-9136
    Keywords: Seismology ; P wave residuals ; Travel-time anomalies ; Earthquake prediction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary Mean travel-time residuals of P waves for the period 1964–1970 at stations in North America and Europe are well separated into large domains of positive and negative values. The spatial distribution of residuals in North America is in good agreement with the structure of the upper mantle obtained from Rayleigh wave dispersion and is in accord with magnitude anomalies and heat flow data. A systematic variation of residuals in time is found to be sensitive to major changes in the nature of the earthquake source distribution, as for example aftershocks, as well as to changes in methods of detection of first arrivals. Residuals at neighboring stations are correlated up to distances of the order of 2°. Half year mean residuals at stations within 2° distance from the epicenters of strong earthquakes have a sudden jump 1.5 years before the occurrence of an earthquake. A formal algorithm based on this pattern permits prediction of the times of all 16 earthquakes with magnitudeM≥7.5 occurring during the interval 1966–1972. Although the average duration of the alarm periods is about half the total time interval of the catalog, so that the algorithm has no practical importance, these results are statistically significant on a 99% level of confidence.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 115 (1977), S. 667-673 
    ISSN: 1420-9136
    Keywords: Seismology ; Hypocenter determination ; Focal coordinate determination ; Near earthquakes location
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary A new computation method is described which determines the focal coordinates, theP n-andP G-velocity, the focal time and the Moho-depth in the case of near earthquakes. The method is provided especially for areas where the crustal parameters are insufficiently known. It presumes that the standard error ofP n-andP G-arrival times is a minimum. The problem turns out to represent the solution of a set of at least seven equations with seven unknown parameters. Four of these unknowns can be separated in advance. This leads to a considerable simplification. The three remaining unknowns are the focal coordinates. Their best fitting values are found by the gradient method. An example is presented which shows how errors can arise if the initial trial coordinate is chosen at an unfavourable position.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 115 (1977), S. 655-666 
    ISSN: 1420-9136
    Keywords: Seismology ; Greece ; Plate tectonics ; Focal mechanism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary An attempt has been made to interpret the striking difference, in focal properties, between the intermediate and shallow earthquakes in Central Greece and an observed time sequence of these shocks by a lithospheric model. This model consists of a lithospheric slab descending from the Ionian to the Aegean and a back-arc expanding Aegean lithosphere. Thrust faulting near the top surface of the slab, caused by the sinking of the slab, triggers spreading and normal faulting in the back-arc Aegean region.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 117 (1979), S. 1045-1049 
    ISSN: 1420-9136
    Keywords: Seismology ; Surface waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary Alsop's method (1966) for the non-normal passage of surface waves through a vertical discontinuity is improved by using a new functional to be made stationary on the plane of discontinuity. The modified functional has the dimension of an energy flux and is characterized by the discontinuous surface wave displacements and stresses on the vertical discontinuity. Model calculations which were carried out for SV-waves and Love waves show that the new version of Alsop's method yields in all respects more consistent results than the old one.
    Notes: Zusammenfassung Die Methode von Alsop (1966) für den Durchgang von schräg einfallenden Oberflächenwellen durch eine vertikale Diskontinuität wird durch Verwendung eines neuen Funktionals, das auf der Diskontinuitätsfläche stationär sein soll, verbessert Das modifizierte Funktional hat die Dimension eines Energieflusses und wird durch diejenige Spannungs- und Verschiebungsdiskontinuität charakterisiert, die durch das Oberflächenwellenfeld auf der Diskontinuitätsfläche erzeugt wird. Modellrechnungen für SV-Wellen und Lovewellen zeigen, daß die neue Version von Alsoos Verfahren in jeder Hinsicht konsistentere Ergebnisse als die bisherige liefert.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 118 (1980), S. 1170-1178 
    ISSN: 1420-9136
    Keywords: Seismology ; Love waves ; Laterally nonhomogeneous layer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Rayleigh's principle and the concept of the local wave number have been utilised for the approximate determination of the dispersion of Love waves propagating in a laterally heterogeneous layer lying over a homogeneous half-space. The shear wave velocity and the rigidity in the surface layer have been assumed to decrease with the increase of the lateral distance from the origin. The range of validity of the dispersion equation obtained by this method has been examined critically. It was found that: (a) for existence of Love waves the minimum value of shear wave velocity in the layer must be less than that in the matter below, and (b) the phase velocity of Love waves decreases with the increase of the lateral distance from the origin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 118 (1980), S. 1209-1213 
    ISSN: 1420-9136
    Keywords: Seismology ; Phase velocity dispersion ; Rayleigh waves ; ‘Hedgehog’ inversion method ; Lithosphere-asthenosphere system in Europe
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 134 (1990), S. 79-92 
    ISSN: 1420-9136
    Keywords: Seismology ; earthquake prediction ; self-similarity ; algorithm CN ; Central Italy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The Time of Increased Probability (TIP) for the occurrence of a strong earthquake is determined in Central Italy. This is done with an algorithm that has been successfully applied in other regions of the world (algorithm CN, from the initials of California and Nevada, where the first diagnoses of TIPs were made). The use of normalized functions allows direct application of the orginal algorithm to the new region being studied, without anyad hoc adjustment of the parameters. Retrospective analysis carried on until 1986 shows that TIPs occupy 26 percent of the total time considered and precede four out of five strong earthquakes. Forward monitoring indicates the possible existence of a TIP started in May 1988. Several tests indicate that the results obtained are quite stable, even when using catalogues from different agencies. Apart from obvious practical interest, this research is essential for the worldwide investigation of self-similarity in the origin of strong earthquakes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 116 (1978), S. 1262-1273 
    ISSN: 1420-9136
    Keywords: Seismology ; African Rift ; P-wave velocity beneath Africa ; Upper mantle structure for Africa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract AP-wave velocity model for the upper mantle beneath eastern and southern Africa is proposed. The top 250 km of the model is characterized by relatively low velocities similar to those deduced for the upper mantle beneath the western United States of America. At greater depths, the velocities gradually change to normal mantle values.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 116 (1978), S. 1299-1306 
    ISSN: 1420-9136
    Keywords: Seismology ; Rayleigh wave dispersion ; Phase velocity of Rayleigh waves ; German Dem. Rep., Rayleigh waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary The phase velocity curve of Rayleigh-waves is determined for a profile crossing the area of GDR from south to north. Two different methods of seismogram processing are used which are discussed in detail. The phase velocities found are checked for compatibility. An inversion of a common phase velocity curve is done by using hedgehog procedure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 135 (1991), S. 61-75 
    ISSN: 1420-9136
    Keywords: Seismology ; seismic networks ; artificial intelligence ; expert systems ; automatic interpretation ; seismic event detection ; data compression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The focus-of-attention techniques implemented in SNA2, a knowledge-based system for seismogram interpretation, are presented. They consist of data compression of the input digital records, scanning of the compressed traces to detect candidate seismograms and extraction of seismogram features. A criterion is given to rate the clarity of seismograms; the clarity defines the order in which the system will consider them to build up the interpretation. The proposed techniques are simple and fast; they allow quick rejection of noise and focussing the attention of the system on the portions of traces containing relevant information.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...