Earthquake aftershocks as green functions pdf

A waveform study of locally recorded aftershocks of the 1971 san fernando earthquake. Pdf empirical greens functions from small earthquakes. Strong motion simulation using stochastic greens function. Seismic hazard assessment with the aid of empirical greens functions.

Greens function, earthquake record, shake table test, similitude requirement. Empirical green s function analysis of geos and terrascope data by s. In section 5 we invert these source time functions to determine the slip distribution on the fault plane. Evaluation of greens function when simulating earthquake records. We performed the empirical green s function method egfm to simulate the strong ground motion of this event and the largest aftershock of local magnitude m w 4. The method included using an earthquake record as an empirical greens. Pdf ground motion prediction with the empirical greens. Seismograms from 52 aftershocks of the 1971 san fernando earthquake recorded at 25 stations distributed across the san fernando valley are examined to identify empirical green s functions, and.

In section 6 we perform an aftershock relocation of all the earthquakes that occurred in the region since the 1994 northridge earthquake. Mori and frankel, 1990 and extract source time functions. Empirical green s functions from small earthquakes. Over the last couple of decades, empirical greens functions egfs have. Seismograms from 52 aftershocks of the 1971 san femando earthquake recorded at 25 stations distributed across the san femando valley are examined to identify empirical greens functions, and. A method is presented for modeling earthquake strong ground motion, which uses the aftershocks associated with a large earthquake as green s functions. Pdf an assessment of uncertainties for ground motion predictions with the aid of the. A major earthquake, with a large rupture surface, is modeled by a collection of point sources distributed over the fault plane. Green s function in the elastodynamic wave theory means the displacement at a point due to a point force acting at another point and is a tensor that has 3 by 3 components. Earthquake aftershocks as greens functions hartzell 1978. Empirical greens function analysis of recent moderate. A method is presented for modeling earthquake strong ground motion, which uses the aftershocks associated with a large earthquake as greens functions.

The waveform of a small earthquake is used as an empirical green function to remove the path and site. Forecasting of the first hour aftershocks by means of the. Abdelfattah national research institute of astronomy and geophysics, helwan, cairo, egypt abstract the rupture process of a moderate earthquake m 4. Data the april 26 and 27, 1997, earthquakes were well.

Empirical green functions 7 we use empirical green function deconvolutions to remove path and site effects from the p waveforms e. Pdf application of empirical greens functions in earthquake. Shortterm aftershock forecasting staf models 1,2,3 are based on the omoriutsu ou law 4 which states that the rate of aftershocks with magnitude m above a threshold m c, at time t. Fine structure of the rupture zone of the april 26 and 27. Stress drops and radiated energies of aftershocks of the. Earthquake aftershocks as greens functions hartzell. Source characteristics of a moderate earthquake m 4. Around 40 aftershocks were recorded by afad within initial 24 hours. Applying the empirical greens function egf method to two sets of m 46. Fourier, grenoble, france, 2 mssp, nilore, islamabad, pakistan. Pdf ground motion prediction with the empirical greens function.