Podrobnosti záznamu

Název
    The peak frequency of direct waves for microseismic events
Autor
    Ali, M.Y.
    Eisner, Leo
    Gei, D.
    Hallo, M.
    Opršal, I.
Jazyk
    anglicky
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    Geophysics
Svazek/č.
    Roč. 78, č. 6
Rok
    2013
Poznámky
    Projekt: GAP210/12/2451, GA ČR3cav_un_auth*0284895
    Rozsah: 5 s. : P
Předmětová kategorie
    attenuation
    inversion
    microseismicity
Klíčové slovo
    Direct
    Events
    Frequency
    Microseismic
    Peak
    Waves
Abstrakt (anglicky)
   Direct seismic waves (P- or S-waves) are used to locate and further characterize microseismic events. The resolution of information obtained from direct waves depends on the peak frequencies of the waveforms. The peak frequency results from combination of the source, propagation, and the receiver effects. For frequencies below the corner frequency, propagation effects control the peak frequency in observed seismograms of microseismic events. The frequency dependence of direct body waves can be modeled by attenuation, specifically the global attenuation factor. This model is consistent with observed data along surface profiles explaining the difference between the peak frequencies of P- and S-waves. In addition, the model is consistent with the peak frequencies observed on downhole monitoring arrays. This can be used to invert effective attenuation providing additional unique measurement from microseismic events.
   The corner frequency can be estimated from the average stress drop and analytical source models such as a circular crack model. Typical stress drops for various magnitude ranges are discussed. The peak frequencies are usually below the corner frequencies of microseismic events smaller than moment magnitude 0.7 for surface monitoring and moment magnitude −0.5 for downhole monitoring. Understanding of the frequency dependence of the direct waves allows us to optimally design monitoring networks and mainly invert effective attenuation providing unique measurement from microseismic monitoring..
Přispěvatel
    AV ČR Brno, Ústav struktury minerálů a hornin
Kód přispěvatele
    AV ČR, ÚSMH
Zdrojový formát
    U
Datum importu
    24. 10. 2014