Rupture history of the 1997 Cariaco, Venezuela, earthquake from teleseismic P waves

C. Mendoza

doi:10.1029/1999gl011278

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Rupture history of the 1997 Cariaco, Venezuela, earthquake from teleseismic P waves

C. Mendoza

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Abstract

A two-step finite-fault waveform inversion scheme is applied to the broadband teleseismic P waves recorded for the strike-slip, Cariaco, Venezuela, earthquake of 9 July 1997 to recover the distribution of mainshock slip. The earthquake is first analyzed using a long narrow fault with a maximum rise time of 20 sec. This line-source analysis indicates that slip propagated to the west with a constant rupture velocity and a relatively short rise time. The results are then used to constrain a second inversion of the P waveforms using a 60-km by 20-km two-dimensional fault. The rupture shows a zone of large slip (1.3-m peak) near the hypocenter and a second, broader source extending updip and to the west at depths shallower than 5 km. The second source has a peak slip of 2.1 meters and accounts for most of the moment of 1.1 × 10 26 dyne-cm (6.6 M w w) estimated from the P waves. The inferred rupture pattern is consistent with macroseismic effects observed in the epicentral area.

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C. Mendoza. 2000-05-15. Rupture history of the 1997 Cariaco, Venezuela, earthquake from teleseismic P waves. https://doi.org/10.1029/1999gl011278

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