CAJ | 학술논문

使用最近构建的虚拟全球地震台网记录的波形数据，采用OpenMP的并行编程技术优化原有算法，研制了基于W震相技术的全球强震（MW≥6．5）矩心矩张量自动反演系统．为了评估该系统的准确度和时效性，将离线自动测定的2008年1月-2013年7月全球140次地震（MW6．5-9．0）的矩心矩张量与全球矩心矩张量工作组（GCMT）的结果进行了比较．结果表明：该系统可准确测定全球MW≥6．5地震的矩张量，绝大多数地震矩震级与GCMT 给出的矩震级呈现出良好的线性趋势，两者之差ΔMW 的标准方差约0．13，ΔMW 位于区间（-0．2，0．2）的地震占总数的96％；地震矩6个分量分别与GCMT 相应的结果沿对角线近线性分布，多数地震矩心水平位置与GCMT给出的矩心水平位置比较接近，两者间大圆弧距离位于区间（0，50 km）的地震次数占总数的84％；在台站覆盖较均匀的条件下，该系统能够实现震后25-40分钟自动准确测定全球MW≥6．5地震的矩心矩张量．
사용최근구건적허의전구지진태망기록적파형수거，채용OpenMP적병행편정기술우화원유산법，연제료기우W진상기술적전구강진（MW≥6．5）구심구장량자동반연계통．위료평고해계통적준학도화시효성，장리선자동측정적2008년1월-2013년7월전구140차지진（MW6．5-9．0）적구심구장량여전구구심구장량공작조（GCMT）적결과진행료비교．결과표명：해계통가준학측정전구MW≥6．5지진적구장량，절대다수지진구진급여GCMT 급출적구진급정현출량호적선성추세，량자지차ΔMW 적표준방차약0．13，ΔMW 위우구간（-0．2，0．2）적지진점총수적96％；지진구6개분량분별여GCMT 상응적결과연대각선근선성분포，다수지진구심수평위치여GCMT급출적구심수평위치비교접근，량자간대원호거리위우구간（0，50 km）적지진차수점총수적84％；재태참복개교균균적조건하，해계통능구실현진후25-40분종자동준학측정전구MW≥6．5지진적구심구장량．
We develop an automatic centroid moment tensor (CMT )inversion system for large earthquakes (MW≥6 .5 )at global scale based on the W-phase method.We use seismic waveforms observed by global virtual seismic networks including Chinese stations,which have been recently set up.To speed up the calculation of moment tensor solutions,the W-phase method is parallelized using openMP.In order to assess the accuracy and timeliness of this implemen-tation,automatic moment tensor solutions for 140 global events (MW6.5-9.0) are determined offline.Compared with the global CMT (GCMT)solutions,the result indicates that this system mentioned is able to precisely retrieve CMT so-lutions of global events with MW≥6 .5 .There is remarkably good linear rela-tionship between the moment magnitude of W-phase CMT and GCMT.The standard deviation of the magnitude differenceΔMW is about 0 .1 3 ,and 9 6 per-cent of the inversions yield a MW within MW-GCMT from the GCMT ± 0 .2 .In comparison with the GCMT solutions,six elements of moment tensors derived show nearly linear distribution along the diagonal,respectively.84 percent of inversions yield a great-circle distance smaller than 50 km between the CMT and GCMT centroids.As shown above,majority of the centroids are very similar with the GCMT centroids.When the data coverage is sufficient,this system can thus automatically determine the CMT of global earthquakes with MW≥6 .5 in between 25 min and 40 min after the origin time.