Tracking the Rupture of the 2008 Wenchuan Earthquake by Using the Relative Back-Projection Method

Hao, Zhang; Ge, Zengxi

doi:10.1785/0120090243

Cited by 56 publications

(45 citation statements)

References 20 publications

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“…This study employed the two-step back-projection method described by Zhang and Ge (2010). In the first step, P waves were back-projected to find locations of the rupture fronts at the apparent rupture times.…”

Section: Methodsmentioning

confidence: 99%

“…Meanwhile, the calculations of the back-projection method are so straightforward that it takes no more than half an hour to effectively image the rupture process. To image the two-dimensional spatial rupture process of the 2011 Tohoku Earthquake, we apply here a two-step back-projection method (Zhang and Ge, 2010) to process the broadband teleseismic P waves that were recorded by 151 seismic stations of the European seismic network, referred to as "the Euro network".…”

Section: Introductionmentioning

confidence: 99%

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Three sub-events composing the 2011 off the Pacific coast of Tohoku Earthquake (M w 9.0) inferred from rupture imaging by back-projecting teleseismic P waves

Zhang

Ding

2011

Earth Planet Sp

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High-quality vertical component seismograms of teleseismic P waves recorded at 151 stations of the European seismic network have been used to image the rupture process of the 2011 Tohoku Earthquake rapidly by a two-step back-projection method. The spatio-temporal distribution of rupture fronts suggests that the earthquake ruptured northeastwards and southwestwards over a total length of more than 340 km during at least 143 s. The fact that three fault segments ruptured at regions having different lateral heterogeneities implies that the earthquake comprised three sub-events. The first sub-event ruptured northeastwards during the first 25 s, and then turned to the northwest direction. The second sub-event ruptured at a relatively high speed of 2.78∼4.70 km/s. The third sub-event ruptured with a direction variation from southwest to southeast near the latitude of 37• . In addition, considering that the first front of the second sub-event appeared at 74.6 s and was about 28 km away from the epicenter, we propose that the second sub-event might have been triggered by the localized increase in tectonic stress in the vicinity of the hypocenter that resulted from the rupture of the first sub-event.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Three sub-events composing the 2011 off the Pacific coast of Tohoku Earthquake (M w 9.0) inferred from rupture imaging by back-projecting teleseismic P waves

Zhang

Ding

2011

Earth Planet Sp

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“…As shown by Ishii et al (2005), the back-projection can image the rupture extent, duration and speed of large earthquakes. Past studies have estimated the rupture velocities of the Denali and Kokoxili earthquakes (Walker and Shearer, 2009) and 2008 Wenchuan, China earthquake (Xu et al, 2009;Mori and Smyth, 2009;Zhang and Ge, 2010). For large earthquakes, rupture velocity is an important parameter that reflects the fault properties and rupture complexity.…”

Section: Introductionmentioning

confidence: 99%

Rupture process of the 2011 off the Pacific coast of Tohoku Earthquake (M w 9.0) as imaged with back-projection of teleseismic P-waves

Wang

Mori

2011

Earth Planet Sp

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We use the back-projection method, with data recorded on the dense USArray network, to estimate the rupture propagation for the M w 9.0 earthquake that occurred offshore of the Tohoku region, Japan. The results show a variable rupture propagation ranging from about 1.0 to 3.0 km/s for the high-frequency radiation. The rupture propagates over about 450 km in approximately 150 s. Based on the rupture speed and direction, the highfrequency source process can be divided into two parts. The first part has a relatively slow rupture speed of 1.0 to 1.5 km/s and propagates northwestward. In the second part, the rupture progresses southwestward starting with a slow speed of about 1.5 km/s and accelerating to about 3.0 km/s. We see three large pulses at 30 s, 80 s and 130 s. The first two, including the largest second pulse, were located 50 to 70 km northwest of the epicenter. The third occurred about 250 km southwest of the epicenter. The variability of rupture velocity may be associated with significant changes of physical properties along the fault plane. Areas of low/high rupture speed are associated with large/small energy releases on the fault plane. These variations may reflect the strength properties along the fault. Also, locations of the high-frequency radiation derived from the back-projection analysis are significantly different from the areas of very large slip for this earthquake.

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“…These faults were relatively quiescent in seismicity (Loveless and Meade 2011;Meade 2007). Source inversions based on teleseismic data showed a pattern of double-peak energy release during rupture (e.g., Ji and Hayes 2008;Nakamura et al 2010;Zhang and Ge 2010;Zhang et al 2009). The first peak was near Yingxiu-Hongkou, Wenchuan about 10-20 s after the initial burst, and the second energy peak came 50 s later near Beichuan.…”

Section: Introductionmentioning

confidence: 99%

Focal Mechanism Solutions of the 2008 Wenchuan earthquake sequence from P-wave polarities and SH/P amplitude ratios: new results and implications

Tian

Ning

Yu³

et al. 2013

Earthq Sci

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The 2008 Wenchuan earthquake, a major intraplate earthquake with M w 7.9, occurred on the slowly deforming Longmenshan fault. To better understand the causes of this devastating earthquake, we need knowledge of the regional stress field and the underlying geodynamic processes. Here, we determine focal mechanism solutions (FMSs) of the 2008 Wenchuan earthquake sequence (WES) using both P-wave first-motion polarity data and SH/P amplitude ratio (AR) data. As P-wave polarities are more reliable information, they are given priority over SH/

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Tracking the Rupture of the 2008 Wenchuan Earthquake by Using the Relative Back-Projection Method

Cited by 56 publications

References 20 publications

Three sub-events composing the 2011 off the Pacific coast of Tohoku Earthquake (M w 9.0) inferred from rupture imaging by back-projecting teleseismic P waves

Three sub-events composing the 2011 off the Pacific coast of Tohoku Earthquake (M w 9.0) inferred from rupture imaging by back-projecting teleseismic P waves

Rupture process of the 2011 off the Pacific coast of Tohoku Earthquake (M w 9.0) as imaged with back-projection of teleseismic P-waves

Focal Mechanism Solutions of the 2008 Wenchuan earthquake sequence from P-wave polarities and SH/P amplitude ratios: new results and implications

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