Structural Relationship Between the 2008 M8 Wenchuan and 2013 M7 Lushan Earthquakes Viewed by Fault-Zone Trapped Waves

Author(s):  
Yong-Gang Li ◽  
Jin-Rong Su ◽  
Tian-Chang Chen ◽  
Peng Wu
2004 ◽  
Vol 31 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Yong-Gang Li ◽  
John E. Vidale ◽  
Elizabeth S. Cochran

2005 ◽  
Vol 18 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Song-lin Li ◽  
Xian-kang Zhang ◽  
Ji-chang Fan

1998 ◽  
Vol 103 (B4) ◽  
pp. 7247-7263 ◽  
Author(s):  
Yong-Gang Li ◽  
Keiiti Aki ◽  
John E. Vidale ◽  
Mark G. Alvarez

2013 ◽  
Vol 4 (3) ◽  
pp. 48-52
Author(s):  
Sun Yi ◽  
Lai Xiaoling

2011 ◽  
Vol 2 (2) ◽  
pp. 66-70 ◽  
Author(s):  
Lai Xiaoling ◽  
Sun Yi

2015 ◽  
Vol 202 (2) ◽  
pp. 933-942 ◽  
Author(s):  
Z.E. Ross ◽  
Y. Ben-Zion

1990 ◽  
Vol 80 (5) ◽  
pp. 1245-1271 ◽  
Author(s):  
Y.-G. Li ◽  
P. C. Leary

Abstract Two instances of fault zone trapped seismic waves have been observed. At an active normal fault in crystalline rock near Oroville in northern California, trapped waves were excited with a surface source and recorded at five near-fault borehole depths with an oriented three-component borehole seismic sonde. At Parkfield, California, a borehole seismometer at Middle Mountain recorded at least two instances of the fundamental and first higher mode seismic waves of the San Andreas fault zone. At Oroville recorded particle motions indicate the presence of both Love and Rayleigh normal modes. The Love-wave dispersion relation derived for an idealized wave guide with velocity structure determined by body-wave travel-time inversion yields seismograms of the fundamental mode that are consistent with the observed Love-wave amplitude and frequency. Applying a similar velocity model to the Parkfield observations, we obtain a good fit to the trapped wavefield amplitude, frequency, dispersion, and mode time separation for an asymmetric San Andreas fault zone structure—a high-velocity half-space to the southwest, a low-velocity fault zone, a transition zone containing the borehole seismometer, and an intermediate velocity half-space to the northeast. In the Parkfield borehole seismic data set, the locations (depth and offset normal to fault plane) of natural seismic events which do or do not excite trapped waves are roughly consistent with our model of the low velocity zone. We conclude that it is feasible to obtain near-surface borehole records of fault zone trapped waves. Because trapped modes are excited only by events close to the fault zone proper—thereby fixing these events in space relative to the fault—a wider investigation of possible trapped mode waveforms recorded by a borehole seismic network could lead to a much refined body-wave/tomographic velocity model of the fault and to a weighting of events as a function of offset from the fault plane. It is an open question whether near-surface sensors exist in a stable enough seismic environment to use trapped modes as an earth monitoring device.


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