Podrobnosti záznamu

Název
    3D hybrid ray-FD and DWN-FD seismic modelling for simple models containing complex local structures
Údaj o odpovědnosti
    Ivo Opršal, Johana Brokešová, Donat Fäh, Domenico Giardini
Autor
    Brokešová, Johana, 1963-
    Fäh, Donat
    Giardini, Domenico
    Opršal, Ivo
Jazyk
    anglicky
Zdrojový dokument - seriál
    Studia geophysica et geodaetica
Svazek/č.
    Vol. 46, no. 4
Strany
    p. 711-730
Rok
    2002
Poznámky
    10 obr., 1 tab.
    il.
    Obsahuje bibliografické odkazy
    Zkr. název ser.: Stud. geophys. geod. (Praha)
Klasifikační znak
    55
    550.3
Skupina konspektu
    53
    55
Předmětová skupina
    fyzika Země
    modelování
    planeta Země
    seizmická vlna
    seizmologie
Geografické jméno
    Země
Klíčové slovo
    3D
    Complex
    Containing
    DWN-FD
    Hybrid
    Local
    Modelling
    Models
    Ray-FD
    Seismic
    Simple
    Structures
Abstrakt (anglicky)
   Hybrid approaches find broad applications wherever all-in-one modelling of source, path, and site effects is too expensive. Our new 3D hybrid approach allows to compute the seismic wavefield in elastic isotropic models containing a complex local structure embedded in a large, but considerably simpler, regional structure. The hybrid modelling is realized in two successive steps. In the 1st step, the ray or discrete wave number (DWN) method is used to compute the seismic wavefield due to the source and simple regional structure. The complex local structure is not present. Thus, the excitation contains the source and regional path effects. The time history of this wavefield (excitation), recorded at the points of so called excitation box, is stored on a disk. The excitation box envelopes a small portion of a computational domain.
   The 2st step of the hybrid method, now containing the complex local structure, is computed by finite differences (FD) inside the excitation box and its close vicinity. The excitation from the 1st step is now used to inject the 1st step wavefield into the 2st step computation. After that, the hybrid combination of the 1st and 2nd steps contains the source, regional path, and local structure effects at reasonably lower computational costs than in case of all-in-one modelling. The 3D ray-FD method is tested on models in which the locally complex structure is the well-known Volvi lake basin, embedded in various 1D structures. The wavefield is excited by the point source situated outside the basin. Although the structure outside the excitation box may be less dimensional (2D, 1D, homogeneous), the whole problem is actually 3D due to the 3D features of the structure inside the excitation box, 3D shape of the excitation box, and arbitrary source |excitation-box configuration.
   Simple (1D) structures outside the excitation box allow for comparison with the alternative hybrid DWN-FD results. However the ray method is suitable for computation of 3D regional structures outside the excitation box. The results from both approaches show a very good agreement for realistic crustal and local structural models
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    28. 3. 2008
Datum importu
    8. 8. 2012