[1]LIU Li-fang,MAO Hui-ling,SU You-jin,et al.Determining Focal Mechanism Solution of the 2000 Yao'an MS6.5 Earthquake Sequence Using the First Motion and Amplitude Ratio of P and S wave[J].Journal of Seismological Research,2009,32(01):25-30.
Copy
Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
32
Number of periods:
2009 01
Page number:
25-30
Column:
Public date:
2009-01-23
- Title:
-
Determining Focal Mechanism Solution of the 2000 Yao'an MS6.5 Earthquake Sequence Using the First Motion and Amplitude Ratio of P and S wave
- Author(s):
-
LIU Li-fang; MAO Hui-ling; SU You-jin; QIN Jia-zheng
-
(Earthquake Administration of Yunnan Province,Kunming 650224,Yunnan,China)
-
- Keywords:
-
first motion; amplitude ratio; focal mechanism solution; Yao'an earthquake
- CLC:
-
P315.3+3
- DOI:
-
-
- Abstract:
-
We calculate the focal mechanisms of 14 earthquakes with M≥3.0 of the 2000 Yao'an MS6.5 earthquake sequence using the first motions of P,SV and SH waves and their amplitude ratios.The main seismogenic fault of the Yao'an earthquake trends in NW and has high dip angle,showing the feature of right lateral strike-slip under nearly horizontal main pressure stress.The focal faults of the Yao'an earthquake sequence mainly move by strike-slip with sporadic oblique-slip faulting under horizontal or nearly horizontal main pressure stress,and in 1-3 days after the mainshock,the fault slips by the way above mentioned,but in 3-30 days after the mainshock by the way of strike-slip.The azimuth of P-axis and T-axis changes with the direction of structural stress field regularly from consistently to inconsistently again to consistently.During the activity of strong aftershocks,the faults move mainly under horizontal or nearly horizontal main pressure stress,with certain oblique.The stress field shows obvious adjustment process after the mainshock.