摘要
摘要探讨了利用接收函数方位变化研究各向异性复杂地区速度结构的可能性。详细介绍了具有任意对称轴方向的横向各向同性系统中介质响应的计算过程,并将利用接收函数方位变化研究地壳各向异性的方法应用于华北太行山地区。结果表明,研究台站下方地壳具有明显的各向异性特征,其中地表盖层表现为8%-15%的慢轴型各向异性;深部地壳各向异性略小,表现为3%-5%的快轴型各向异性特征,不同台站获得的各向异性对称轴的方向及深度分布不具有明显的一致性,区域构造环境的变化可能是导致地壳各向异性存在的原斟。
We discussed the possibility of studying crust anisotropy by analyzing azimuthal variation of the receiver functions and presented a technique for computing the transmission response of a flat-layered medium with arbitrarily oriented hexagonally symmetric anisotropy using the reflectivity algorithm. Using this method we investigated the crust anisotropy of Taihang Mountain Range (TMR). Our result shows that there is significant anisotropy with a slow sym- metry axis in upper crust and a fast symmetry axis in lower crust. Theanisotro py magnitude of about 8%-15% is found in the upper crust and a smaller magnitude of about 3%-5% in the lower crust. Orientation of the symmetry axes and the depth of anisotropy appearance as deduced from the seismic records of four individual seismic stations are different from each other. The crust anisotropy beneath the four stations may be associated with the local crustal fabrics in a small area.
出处
《地震学报》
CSCD
北大核心
2008年第4期355-366,441,共12页
Acta Seismologica Sinica
基金
National Natural Science Foundation of China (40774042 and 90714012)
关键词
接收函数
各向异性
方位变化
太行隆起地区
receiver function
anisotropy
azimuthal variation
Taihang Mountain Range