详细信息   

• 责任者：Chong Jiajun (Mengcheng National Geophysical Observatory ; School of Earth and Space Sciences ; University of Science and Technology of China ; Hefei 230026 ; China) ; Ni Sidao 1
• 刊名：Chinese Journal of Geophysics
• 出版年：2010
• 卷期：53(11)
• 关键词：震源深度 ; focal depth ; 江西 ; Jiangxi Province
• 页码：p.2620-2630
• 图表：5 illus., 1 table, 36 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

A seimic phase is often observed between P and S of continental earthquakes for epicentral distances less than 50 km in regions with simple crustal structure. It is stronger on radial component than on vertical component, and its tangential amplitude is weak. The seismic phase is also less impulsive than P waves. From synthetic waveforms, the authors find that it is generated when S wave goes upward and is post-critically converted to P wave traveling along the free surface. It  may also contain multiple conversion or reverberations of P wave near free surface.  Waveform study shows that differential time between sPL and direct P is insensitive to epicentral distance, but increases almost linearly with the focal depth. It is used to determine the focal depths for a 2005 earthquake sequence in Jiujiang, China.