Rupture Process of the 1964 MJMA 7.5 Niigata Earthquake Estimated from Regional Strong-Motion Records

2011 ◽  
Vol 101 (4) ◽  
pp. 1871-1884 ◽  
Author(s):  
Y. Shiba ◽  
T. Uetake
Keyword(s):  
Strong Motion ◽  
Rupture Process ◽  
Strong Motion Records

scholarly journals Rupture process of the 1987 Superstition Hills earthquake from the inversion of strong-motion data

1990 ◽  
Vol 80 (5) ◽  
pp. 1079-1098 ◽  
Author(s):  
David J. Wald ◽  
Donald V. Helmberger ◽  
Stephen H. Hartzell
Keyword(s):  
Small Area ◽  
Strong Motion ◽  
Rupture Process ◽  
Imperial Valley ◽  
Strong Motion Records ◽  
Motion Data ◽  
Single Asperity ◽  
The Third ◽  
Rupture Model ◽  
Stress Drops

Abstract A pair of significant earthquakes occurred on conjugate faults in the western Imperial Valley involving the through-going Superstition Hills fault and the Elmore Ranch cross fault. The first event was located on the Elmore Ranch fault, Ms = 6.2, and the larger event on the Superstition Hills fault, Ms = 6.6. The latter event is seen as a doublet teleseismically with the amplitudes in the ratio of 1:2 and delayed by about 8 sec. This 8-sec delay is also seen in about a dozen strong-motion records. These strong-motion records are used in a constrained least-squares inversion scheme to determine the distribution of slip on a 2-D fault. Upon closer examination, the first of the doublets was found to be itself complex requiring two episodes of slip. Thus, the rupture model was allowed to have three separate subevents, treated as separate ruptures, with independent locations and start times. The best fits were obtained when all three events initiated at the northwestern end of the fault near the intersection of the cross-fault. Their respective delays are 2.1 and 8.6 sec relative to the first subevent, and their moments are 0.4, 0.9, and 3.5 × 1025 dyne-cm, which is about half of that seen teleseismically. This slip distribution suggests multi-rupturing of a single asperity with stress drops of 60, 200, and 15 bars, respectively. The first two subevents were confined to a small area around the epicenter while the third propagated 18 km southwestward, compatible with the teleseismic and afterslip observations.

scholarly journals Short-Period Rupture Process of the 2010 Mw 8.8 Maule Earthquake in Chile

2012 ◽  
Vol 28 (1_suppl1) ◽  
pp. 1-18 ◽  
Author(s):  
Sergio Ruiz ◽  
Raúl Madariaga ◽  
Maximiliano Astroza ◽  
G. Rodolfo Saragoni ◽  
María Lancieri ◽  
...  
Keyword(s):  
Strong Motion ◽  
Rupture Process ◽  
Rupture Zone ◽  
Strong Motion Records ◽  
Seismic Slip ◽  
Short Period ◽  
Maule Earthquake ◽  
High Frequency Waves ◽  
Continuous Gps ◽  
2010 Maule Earthquake

The 2010 Maule earthquake is one of the largest events ever recorded with modern instruments. We used the continuous GPS (cGPS) records to invert for the kinematic rupture process using an elliptical sub-patch approximation. In agreement with previous inversions, the largest slip is found in the northern part of the rupture zone. By cross-correlating signals from cGPS and strong motion records (SM) located in the northern part of the rupture zone, we identified two distinct seismic pulses. Using the arrival time of these pulses, we propose a short-period (<20 s) rupture process, the zone where these pulses are generated is situated near 35.5°S, in agreement with the area with the highest seismic slip and maximum observed intensity. Finally, we compare the strong motion records at the same sites for the 1985 Mw 8 Valparaíso earthquake and the Maule earthquake. We found that spectral contents and duration of the records of these two events were very similar. Thus, at least in the northern part of the rupture, the Maule earthquake radiated high frequency waves like an Mw 8 earthquake.

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