Influence of attenuation and site on microearthquakes’ spectra in Shillong region, of northeast, India: A case study

• Autorzy: Biswas R. , Baruah S. , Bora D.
• Języki publikacji: EN

Abstrakty

EN

We examine the influence of attenuation and site on the spectra of microearthquakes having origin within the Shillong region. The ratios of spectral amplitudes at lower and higher frequencies are measured for three different stations at varying epicentral distances to estimate Q value for both P- and S-wave in near and sub-surface layer. The average estimates of QP and QS are found to be 178 and 195. The ratio of QS to QP emerges to be greater than unity in major parts of the Shillong area, suggesting dominance of dry crust prevailing in Shillong region. The variation in corner frequencies for these spectra is inferred to be characteristics of the site. Besides, the disparity in spectral content with reference to hard rock site yields the inference that the incoming seismic signals get amplified considerably while traversing from southern part to northeastern part of Shillong, best outlined at 2 to 5 Hz, which is well corroborated by the existing lithology.

Słowa kluczowe

EN

attenuation; site effect; reference site

• Wydawca: Instytut Geofizyki PAN ; Springer
• Czasopismo: Acta Geophysica
• Rocznik: 2013
• Tom: Vol. 61, no. 4
• Strony: 886--904
• Opis fizyczny: Bibliogr. 18 poz.

Twórcy

autor

Biswas R.

• Department of Physics, Tezpur University, Tezpur, Assam, India

autor

Baruah S.

• Geoscience Division, CSIR – North East Institute of Science and Technology, Jorhat, Assam, India

autor

Bora D.

• Department of Physics, Diphu Government College, Diphu, Assam, India

Bibliografia

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