Modelling of multilayered dispersive and dissipative media

• Autorzy: Narayan J.
• Języki publikacji: EN

Abstrakty

EN

This paper presents a frequency domain formulation in agreement with Futterman's third absorption-dispersion relationship, for synthesizing normal incident seismograms for a layered elastic and dissipative media. In the past, synthetic seismograms have been computed in time and frequency domains using attenuation and dispersion phenomena separately as well as simultaneously. The time domain modeling suffers from minimum phase formulation and inadequate treatment of dispersion. Amplitude and phase spectra have been computed using the ratio of spectra of upgoing and downgoing waves in the layers and Fast Fourier Transform (FFT) technique bas been adopted for converting the response in time domain. The results have revealed changes in the reflected wave forms in both frequency and time domains in accordance with the theory of absorption and dispersion phenomena. Results with constant quality factor depict an increase in both attenuative and dispersive effects with a decrease in the quality factor. Frequency dependent and independent quality factors were considered and almost similar responses have been obtained. The time lead caused by dispersion is found to be much smaller when the reference frequency is at the center of the desired frequency band. It has also been observed that the time lead or delay caused by dispersion increases with the travel time. Key words: synthetic seismograms, dispersive media, dissipative media, quality factor.

Słowa kluczowe

EN

synthetic seismograms; dispersive media; dissipative media; quality factor

• Wydawca: Instytut Geofizyki PAN
• Czasopismo: Acta Geophysica Polonica
• Rocznik: 2000
• Tom: Vol. 48, nr 3
• Strony: 347--358
• Opis fizyczny: Bibliogr. 21 poz.

Twórcy

autor

Narayan J.

• Department of Earthquake Engineering, University of Roorkee, Roorkee, Lidia