| 2003年大姚6.2和6.1级地震前三维波速结构的演化 |
| |
| 引用本文： | 周龙泉,刘杰,张晓东.2003年大姚6.2和6.1级地震前三维波速结构的演化[J].地震学报,2007,29(1):12-20. |
| |
| 作者姓名： | 周龙泉 刘杰 张晓东 |
| |
| 作者单位： | （中国北京100036中国地震台网中心) |
| |
| 基金项目： | 国家重点基础研究发展计划(973计划)，中国地震台网中心青年基金 |
| |
| 摘 要： | 尝试在年度尺度上对云南地区地壳速度结构进行成像,以确定2003年大姚地震前三维地壳速度结构的演化,并对其发震成因的介质物性变化进行探讨.检测板分辨试验显示,在年度尺度上,大姚附近区域15km深度上节点解的分辨率在0.6左右;误差分析显示,在震源附近的误差(约0.02km/s)远小于速度变化的幅度(约0.15km/s).研究结果表明,大姚地震前震源区附近形成一条北北西向的高、低波速交界带,其走向与两次大姚地震震源机制解的走向以及通过余震精定位确定的断层走向基本吻合,且震源位于交界带的高波速一侧.此外,大姚地震震后在震源下方形成一低速体.本文得到的大姚地震前的波速结构演化可为探讨其孕震、发震条件提供约束.
|
| 关 键 词： | 大姚地震 速度结构演化 地震层析成像 年度尺度 |
| 文章编号： | 0253-3782(2007)01-0020-11 |
| 修稿时间： | 2006年4月27日 |
EVOLUTION OF 3D VELOCITY STRUCTURE BEFORE DAYAO M6.2 AND M6.1 EARTHQUAKES IN 2003 |
| |
| Zhou Longquan,Liu Jie,Zhang Xiaodong.EVOLUTION OF 3D VELOCITY STRUCTURE BEFORE DAYAO M6.2 AND M6.1 EARTHQUAKES IN 2003[J].Acta Seismologica Sinica,2007,29(1):12-20. |
| |
| Authors: | Zhou Longquan Liu Jie Zhang Xiaodong |
| |
| Abstract: | In this paper the crustal velocity structure are imaged at the annual scale for determining the evolution of 3D velocity structure before the Dayao earthquakes in 2003, and the physical variety of medium are discussed about the cause of earthquake occurrence. The checkerboard resolution tests show that the spatial resolution at 15 km depth is approximate 0.6 around Dayao. The error analyses show that the error (approximate 0.02 km/s) at the focus area is far smaller than the magnitude (approximate 0.15 km/s) of velocity variation. The results of studies show that a NNW-striking juncture zone of high- and low-velocity is produced before Dayao earthquake, whose strike is basically consistent with that of aftershock distribution of Dayao earthquakes and the focal mechanism, and the hypocenters lie on the high-velocity side of juncture zone. Furthermore, there is a low-velocity body under the hypocenters after Dayao earthquakes. The evolution of velocity structure provides restriction for discussing the circumstances of earthquake gestating and occurring. |
| |
| Keywords: | Dayao earthquake evolution of velocity structure seismic tomography annual scaling |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《地震学报》浏览原始摘要信息 |
|
点击此处可从《地震学报》下载全文 |
