中国数字地震台网的接收函数及其非线性反演

M RECEIVER FUNCTIONS AT THE STATIONS OF THE CHINESE DIGITAL SEISMIC NETWORK(CDSN) AND THEIR NONLNEAR INVERSION

利用中国数字台网（CDSN）记录的85个远震事件的宽频带P波波形数据和分离接收函数的最大或然性反褶方法,获得了CDSN台网10个台站不同方位的岩石层接收函数.利用这些台站不同方位的平均接收函数和非线性接收函数反演方法,获得了上述各台站下方100km深度范围内的岩石层S波速度结构.结果表明CDSN台网各台站下方的地壳厚度和岩石层速度结构存在明显的差别.其中,拉萨台下方的地壳厚度为66kin,壳幔界面较模糊,而余山台下方的地壳厚度为34km,壳慢界面两侧速度反差明显.刮用本文方法估计的地壳厚度与已有的结果基本一致,由于CDSN台网覆盖了中国大陆的各主要构造单元,本文的结果为研究中国大陆的岩石层S波速度结构及其横向变化提供了新的证据.

The receiver functions with different azirnths at 10 CDSN stahons have been ob-taned from the broadband P wavefonns of 85 teededc events by using the mul-ti-channel maximal likelihood deconvoluhon meth0d' The lithosPheric S wave velodtystructures down to 100km deep bencath there stations are given by using the nonlinearcomplex driver function spectrum ratio inverson method.Our results show the fine lithospheric S veodty strructures under the CDSN stationsand the dear lateral variahons of the crustal theckness and lithosphtric velodty structuresunder the China continent. In particular, the crust under the Lahsa station is 66 km thick and the crust-mantle boundary is undear. The crust under the Sheshan station is 34 kmthick and the crust-mantle boundary has a sharp velodty contryst. The crustal tanessunder the CDSN stahons from our data is neariy consistent with the resu1tS by other meth-ods. Since the CDSN stahons cover the first-order fornic units of the China continent,otir rmlts provide a new evidence of the lateral inhomogendty of the Chna continentallithosphere.Keyweords:CDSN, Receiver function inverson, Lithosphere velodty structure