摘要
应用一种同时获得地壳上地幔二维速度结构和界面形态的地震走时反演算法 ,对在长白山天池火山区L1 剖面获得的人工地震折射和宽角反射走时数据进行反演 ,得到了该剖面的地壳上地幔二维速度结构和构造 .结果表明 :长白山天池火山口下方中下地壳存在一倒三角状的低速体 ,壳内反射界面和莫霍面一致呈下凹形态 ,幅度 2～ 6km不等 ,形成一个地壳根 ,推测是长白山天池火山系统 .
D velocity structure and tectonics of the crust and upper mantle is revealed by inversion of seismic refraction and wide-angle reflection traveltimes acquired along the profile L1 in the Changbaishan-Tianchi volcanic region. It is used in this study that seismic traveltime inversion for simultaneous determination of 2-D velocity and interface structure of the crust and upper mantle. The result shows that, under Changbaishan-Tianchi crater, there exists a low-velocity body in the shape of an inverted triangle, and the crustal reflecting boundaries and Moho all become lower by a varying margin of 2~6 km, forming a crustal root which is assumed to be the Changbaishan-Tianchi volcanic system. Finally, we make a comparison between our 2-D velocity model and the result from the studies by using trial-and-error forward modeling with SEIS83.
出处
《地震学报》
CSCD
北大核心
2002年第2期144-152,共9页
Acta Seismologica Sinica
基金
中国地震局"九五"重点项目 (95 11 0 2 0 1)资助
