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Rupture history of the 1997 Cariaco, Venezuela, earthquake from teleseismic P waves
Author(s) -
Mendoza C.
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl011278
Subject(s) - hypocenter , geology , seismology , waveform , slip (aerodynamics) , inversion (geology) , fault plane , seismic moment , moment magnitude scale , fault (geology) , geodesy , induced seismicity , tectonics , geometry , physics , mathematics , quantum mechanics , voltage , scaling , thermodynamics
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.