利用远震接收函数研究湖北地区地壳结构

利用2014~2015年湖北数字地震台网30个子台记录的远震波形资料，用频率域反褶积方法提取接收函数，由H-Kappa、CCP叠加方法反演得到各台站下方地壳厚度、泊松比及剖面AA′。结果表明：1）湖北地区地壳厚度总体趋势是西厚东薄，鄂西北、西南地区地壳厚度在45~55 km左右，鄂东地区地壳厚度在30~35 km左右；2）湖北地区泊松比值总体变化不大（0.23~0.27），说明这一地区岩石可能以中度组分为主；3）AA′剖面中出现“楼梯状”Moho面，结合相关文献分析，在武当山地区下方地壳的榴辉岩发生相变，使得相变后的下地壳密度改变而发生拆沉作用，因此鄂西地区地壳厚度发生陡变。

Crustal Structure and Poisson Ratio beneath Hubei Province Derived from Teleseismic Receiver Functions

In this paper, we calculate receiver functions of body waves under 30 stations in Hubei province, using data from the teleseismic earthquake (2014~2015), obtaining thickness, poisson ratio, and CCP profile (AA′). The results show that: (1) the crust thickness in western Hubei is thicker than in the east; crustal thickness in northwest and southwest Hubei is at about 45~55 km, in the east it is about 30~35 km; (2) the poisson ratio in Hubei province is about 0.23~0.27, which may be related to the moderate rock compositions; (3) the Moho surface looks like “stairs”. In combination with related literature analysis, eclogite phase changes occur below the Earth’s crust in the Wudang mountain area, so that the alternating density phase changes of lower crust delamination causes abrupt changes in western Hubei regional crustal thickness.