Journal of Physics of the Earth
Online ISSN : 1884-2305
Print ISSN : 0022-3743
ISSN-L : 0022-3743
Search
Advanced search
OR
Browse
Search
Volume 19, Issue 2
Displaying 1-6 of 6 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • Inferences of a Layered Structure from S Wave Spectra Part 1. Theretical Considerations of S Wave Spectrum Method
    Tuneto KURITA, Takeshi MIKUMO
    1971 Volume 19 Issue 2 Pages 93-110
    Published: June 25, 1971
    Released on J-STAGE: November 12, 2009
    DOIhttps://doi.org/10.4294/jpe1952.19.93
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A method is described to infer a layered structure from the amplitude ratio of the vertical to the horizontal component of SV waves together with the phase difference between them, and also from the corresponding relations between SH waves and the horizontal component of SV waves. The behaviors of these frequency-dependent functions for various models with different layer parameters are investigated, and their applicability to inference of the structure is discussed.
    It is shown that the S wave spectra will be useful to test the appropriateness of probable models derived from P wave spectra and other information, if good records from deep-focus shocks with appropriate epicentral distances are analyzed.
    View full abstract
    Download PDF (1457K)
  • Inferences of a Layered Structure from S Wave Spectra Part 2. Study of the Structure in Selected Regions of Japan
    Tuneto KURITA
    1971 Volume 19 Issue 2 Pages 111-142
    Published: June 25, 1971
    Released on J-STAGE: November 12, 2009
    DOIhttps://doi.org/10.4294/jpe1952.19.111
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The validity of the layered structures formerly inferred from P wave spectra in selected regions of Japan has been confirmed from SV wave spectra. The theoretical consideration was given in Part 1, and in this paper this method has been shown to be very useful. For the Chugoku region and the central mountain area, we have been able to confirm the validity of our previous determination from P wave spectra, although the method failed for the Kanto plain due, we believe, to a lack of high quality in the data. The existence of a low P and S wave velocity layer of about 7.4 and 4.1 km/sec in the uppermost mantle of Japan has been definitely affirmed, showing the characteristic feature of the orogenic region.
    View full abstract
    Download PDF (2230K)
  • Computer Simulation of Hydrodynamic Flow in Two-Fluids Media by MAC-Method
    Toshisuke HIRAMATSU, Yasuo SHIMAZU
    1971 Volume 19 Issue 2 Pages 143-153
    Published: June 25, 1971
    Released on J-STAGE: November 12, 2009
    DOIhttps://doi.org/10.4294/jpe1952.19.143
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Process of movement of ocean current is simulated by a high-speed computer. MAC (Marker And Cell) method for solving two dimensional Navier-Stokes equation is employed and composite media of two fluids with different density and viscosity are considered. Two types of initial conditions are given as follows: horizontally and vertically stratified. Patterns of initial perturbation and of boundary conditions are varied.
    View full abstract
    Download PDF (755K)
  • A Note on the Attenuation of Short Period P and S Waves in the Mantle
    Kei TAKANO
    1971 Volume 19 Issue 2 Pages 155-163
    Published: June 25, 1971
    Released on J-STAGE: November 12, 2009
    DOIhttps://doi.org/10.4294/jpe1952.19.155
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The reciprocal dissipation factor Q of P and S waves is determined by spectral analysis of records of earthquakes whose epicentral distance from Tsukuba ranges from 36 to 76 degrees, with special emphasis on that of short period S waves.
    A constant velocity radiated spectrum near the source is assumed.
    The value of Qβ(Q for S waves) is found between 300 to 2400 in the period range from 0.1 to 1 second, and its average Qβ is 800, whereas Qα (Q for P waves) ranges from 600 to 5000, and its average Qα is 2000. The ratio Qα/Qβ is 2.5.
    Also obtained are Qα and Qβ for the period range from 1 to 10 seconds in order to compare with those of short period P and S waves. It is found that Qα ranges from 150 to 4800, while Qβ is between 150 and 2400 in the period range from 1 to 10 seconds. The average value is 1000 for Qα and 600 for Qβ. The ratio Qα/Qβ is 1.7.
    View full abstract
    Download PDF (562K)
  • Steady Solution for Thermal Convection within the Earth's Mantle
    Jun IRIYAMA, Kazuo FUKUTA, Yasuo SHIMAZU
    1971 Volume 19 Issue 2 Pages 165-173
    Published: June 25, 1971
    Released on J-STAGE: November 12, 2009
    DOIhttps://doi.org/10.4294/jpe1952.19.165
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A linear stability problem for the mantle of the earth is considered. Upper and lower mantle convection currents are assumed to reflect a rapid change in the viscosity at transition zone. The theory of mantle convection proposed by TOZER is adopted as a basis for the present investigation. For appropriate values of physical parameters it is found that the mantle should be in a convective state. Using the minimum temperature assumption, the internal temperature distribution in the presence of mantle convection current is considered.
    The temperature at the bottom of the upper mantle convection cell is about 1450-1650°K regardless of conduction transfer and the thickness of the convecting zone. The temperature gradient within the upper mantle convecting zone differs very little from the adiabatic gradient. The temperature at the core-mantle boundary is about 2100-3800°K.
    View full abstract
    Download PDF (655K)
  • Effect of Horizontal Heterogeneity on the Torsional Oscillation of an Elastic Sphere
    Tatsuo USAMI
    1971 Volume 19 Issue 2 Pages 175-180
    Published: June 25, 1971
    Released on J-STAGE: November 12, 2009
    DOIhttps://doi.org/10.4294/jpe1952.19.175
    JOURNAL FREE ACCESS
    Download PDF (443K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top