Estimation of High-Frequency Wave Radiation Areas of Wenchuan Earthquake by the Envelope Inversion of Acceleration Seismograms and Synthesis of Near-Field Accelerograms
Yin Deyu
Liu Qifang
Abstract：It??s helpful for studying earthquake disaster by estimating seismic oscillation reasonably in Wenchuan area.Based on the line source model,the high-frequency (>1 Hz)wave radiation areas on the Wenchuan earthquake fault plane are inversed by the differential evolution method,using the acceleration envelopes attenuation relationship of Lushan earthquake and envelopes of 30 near-field stations acceleration seismograms in Wenchuan earthquake.The results indicate that the high-frequency wave radiation areas are very nonuni-form,with most of the High-frequency waves radiated in:(1)the surface rupture areas,including Yingxiu,Beichuan and Nanba are-as;(2)the areas close to the boundaries of the asperities,including that with epicentral distance from 60 to 90 km northeast of epicen-ter,and areas 30 km northeast of Beichuan and Nanba;(3)the area within 30 km length near the fault northeastern tip.Both high and low frequency wave radiation were much higher in areas with large surface rupture.Utilizing the inversed high-frequency wave radiation areas and the acceleration envelopes attenuation relationship,near-field accelerations are synthesized.The accelerations in areas with no seismic records are synthesized by the synthetic envelopes and a stationary stochastic process extracted from its near station with similar site conditions.The results could be used as the earthquake input for analyzing seismic damage of structures in Wenchuan earthquake.
Keywords：Wenchuan earthquakehigh-frequency wave radiation area inversionacceleration envelopes attenuation relation-shipdifferential evolutionsynthetic accelerationseismology
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 1781-1793 )