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固体地球物理学术报告通知-20171124 Yehuda Ben-Zion

报告地点: 
教学行政楼706会议室
报告时间: 
2017-11-24 15:00
报告人: 
Yehuda Ben-Zion
报告人简介: 
Yehuda Ben-Zion教授 1990年博士毕业于南加州大学,之后在哈佛大学从事博士后研究并担任副研究员,1997年回到南加州大学分别担任助理/副/正教授。Ben-Zion教授的主要研究兴趣是地震震源和成像研究,是目前国际上最为活跃的地震学家之一,他所带领的研究组非常活跃,最近三年每年在国际知名地球物理杂志发表15篇以上的文章。他目前已经发表了超过200篇的SCI文章,引用总次数超过6500次,是ESI统计的全球地球科学领域引用总次数在1%的科学家。他2011年被选为AGU会士,目前担任JGR-Solid Earth的主编。
报告题目: 
Imaging and monitoring large crustal fault zones
报告内容简介: 

Earthquake ruptures produce rock damage associated with reduction of seismic velocities and increased attenuation. During interseismic periods there is rock healing. Damage generation is resisted by normal stress and healing is enhanced by it, so rock damage is especially pronounced in the shallow crust. Generation and healing of damage over many earthquake cycles produces a flower-shape fault zone structure, with significant damage in the top few km that decreases in amplitude and width with depth. A hierarchical damage structure of this type is observed with multi-scale/signal seismic imaging of crustal faults. Analyses of earthquake waveforms indicate significant co-seismic reduction of seismic properties that can be 30% or more in the top 500 m of the crust, followed by log(t) healing. Analyses of ambient noise detect small changes of properties, using larges time steps and longer periods compared to the earthquake waveform studies. Interpreting the depth section sustaining temporal changes of properties requires using wide range of periods and multiple analysis time steps.