海南岛地壳厚度与泊松比结构  

Crustal structure and Poisson's ratio beneath Hainan Island

作　　者：黄海波[1,2] 丘学林[1] 夏少红[1] 

机构地区：[1]中国科学院边缘海地质重点实验室 中国科学院南海海洋研究所,广东广州510301 [2]中国科学院研究生院,北京100039

出　　处：《热带海洋学报》2012年第3期65-70,共6页Journal of Tropical Oceanography

基　　金：国家自然科学基金项目(41074066;41006028);广东省自然科学基金项目(10451030101004522);国家重点基础研究发展计划项目(2007CB411701)

摘　　要：地壳厚度和泊松比是了解地球内部介质的重要参数,研究二者之间的关系能够为揭示深部地壳结构特征提供重要信息。本文提取了海南岛固定地震台站记录到的远震接收函数波形,通过在地壳厚度和波速比域对壳-幔间断面的Ps转换波及其多次波震相进行振幅叠加,同时参考人工地震探测结果,获得了海南岛地区的地壳厚度和泊松比分布。结果显示:海南岛地区地壳厚度为26—31km;受普遍发育的花岗岩以及火山作用影响,其泊松比值基本小于0.26,地壳厚度与泊松比之间存在正消长关系,表明该区的构造伸展作用主要造成富含镁铁成分的下地壳的明显减薄;部分地区的上地壳可能存在褶皱或逆冲推覆构造,其泊松比出现低值异常。Crustal thickness（H） and Poisson＇s ratio（v） are two important parameters to understand the interior of the Earth. Correlation between the two can reveal important information of the character of the crustal structure.Teleseismic receiver functions recorded by the permanent seismic stations distributed around Hainan Island are extracted to search the Ps converted wave and its multiples from discontinuities in the crust and mantle,and some artificial earthquake probing results are taken for references to determine the average thickness and the Poisson＇s ratio beneath Hainan Island.The results show that the crust thickness of Hainan is 26 31km and the Poisson＇s ratio is lower than 0.26 beneath the island for the widespread granite and volcano activities.This area seems to display a positive correlation between H and v,which indicates that the tectonic extension function is mainly caused the obvious reduction of lower crustal thickness;Poisson＇s ratios in some zones are extremely low,possibly due to fold-thrust belts of the upper crust.

关 键 词：海南岛 接收函数 H-κ叠加 地壳厚度 泊松比 

分 类 号：P738.4[天文地球—海洋地质]