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.

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 Rupture process and coseismic deformations of the 27 February 2010 Maule earthquake, Chile

2011 ◽  
Vol 63 (8) ◽  
pp. 955-959 ◽  
Author(s):  
Nelson Pulido ◽  
Yuji Yagi ◽  
Hiroyuki Kumagai ◽  
Naoki Nishimura
Keyword(s):  
Rupture Process ◽  
Maule Earthquake ◽  
2010 Maule Earthquake

High stress drops of short-period subevents from the 1968 Tokachi-Oki earthquake as observed on strong-motion records

1984 ◽  
Vol 74 (5) ◽  
pp. 1529-1544
Author(s):  
Jim Mori ◽  
Kunihiko Shimazaki
Keyword(s):  
Source Parameters ◽  
High Stress ◽  
Strong Motion ◽  
P Waves ◽  
Strong Motion Records ◽  
Source Dimensions ◽  
Short Period ◽  
High Dynamic ◽  
Stress Drops ◽  
Very High

Abstract Strong-motion records of the 1968 Tokachi-Oki earthquake were examined, and two very high stress drop subevents were identified. The first subevent had been previously located by Nagamune (1969), and the second subevent was located in this study using P waves recorded on short-period WWSSN records. Estimates of source parameters revealed small source dimensions (&lt;1 per cent of the aftershock area) and very high dynamic and static stress drops in the kilobar range for both of the subevents. It is suggested that these subevents are important in driving the main rupture of this earthquake. The two subevents also produced the dominant accelerations on the strong-motion records, and it is shown that high-peak accelerations (150 to 200 cm/sec2) were recorded even at relatively large distances (100 to 200 km).

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