HR: 0800h
AN: S51B-0504    [Abstracts]
TI: A Kinematic Source Inversion Scheme With New Parametrisation
AU: * Burjanek, J
EM: burjanek@karel.troja.mff.cuni.cz
AF: Charles University in Prague, Faculty of Mathematics & Physics, V Holesovickach 2, Praha 8, 18000,
AB: We present a kinematic finite extent source inversion scheme, introducing an innovative parametrization of the problem. Particularly, we assume a spatial slip distribution composed of overlapping 2D Gaussian functions on regular grid. Temporal evolution of slip is described with prescribed slip velocity function, with free rupture velocity and rise time parameters. Fixing the values of rupture velocity and rise time for whole fault makes the problem linear in static slip. The inversion algorithm works as follows. At first we fix rise time and rupture velocity and calculate seismograms for each Gaussian function separately. Then a linear inversion is performed to get optimal weights (=amplitudes) of these Gaussian functions. Such procedure is done for a number of rupture velocity and rise-time distributions. Optimal values of these distributions are obtained by neighborhood algorithm. L2 norm is used as an objective function. The linear inversion for static slip is done with positivity constraint, so called ‘Quadratic programming' was applied to solve such problem. Our method benefits from simplicity of linear problems and favourable spectral properties of Gaussian function. The latter prevent from employment of artificial smoothing operators. Thus a direct insight into spectral properties of the static slip distribution of real earthquakes is obtained. The method has been applied to the 2000 M6.6 Western Tottori, Japan, earthquake.
DE: 7200 SEISMOLOGY
DE: 7215 Earthquake source observations (1240)
DE: 7290 Computational seismology
SC: Seismology [S]
MN: 2007 Fall Meeting