- 责任者：Shen Zhongyin (Key Laboratory of the Earth’s Deep Interior ; Institute of Geology and Geophysics ; Chinese Academy of Sciences ; Beijing 100029 ; China) ; Ai Yinshuang
- 刊名：Chinese Journal of Geophysics
- 出版年：2013
- 卷期：56(10)
- 关键词：地球内核 ; inner core ; 走时残差 ; traveltime residuals
- 页码：p.3324-3333
- 图表：7 illus., 1 table, 37 refs.
- 分类号：0400
- issnNo：ISSN0001-5733
- isbnNo：CN11-2074/P
Reflected from inner core boundary, pre-eritical PKiKP, associated with core-mantle boundary reflection phase PeP to suppress signal of non-inner-core origin, can provide the most direct and concise high-resolution constraint on properties of inner core boundary. Out of one- year data collected by dense portable array located on the northwestern brink of North China Craton, we get 73 pairs of PcP-PKiKP waveforms from 8 earthquake events, covering a sweep from Korean Peninsula to Northeast and Central China. Travel time residue and amplitude ratio observations have been systematically analyzed, with the following conclusions obtained： （1） Dense array could be used as a powerful tool for detecting pre-critical PKiKP and shallow-origin events can also provide good observation data. （2） Geographical distribution of travel time residues show an abrupt change into negative anomaly 〉0.5 s within 70 km distance on ICB）from northwest to southeast, indicating the undulation of inner core boundary of the studying area no larger than 3 km. （3） Relative amplitude ratios show a systematically southeastern increasing of inner core boundary density contrast, implicating small-scale perturbation of inner core crystallization environment.