海南岛及邻区地壳S波Q值成像特征研究  

CRUSTAL Q_s TOMOGRAPHY IN HAINAN ISLAND AND ADJACENT REGIONS

作　　者：王惠琳[1] 徐晓枫[1] 周龙泉[2] 张晓东[3] 沈繁銮[1] 李志雄[1] 占伟[4] 

机构地区：[1]海南省地震局,海口570203 [2]中国地震台网中心,北京100045 [3]中国地震局地震预测研究所,北京100036 [4]中国地震局第一监测中心,天津300180

出　　处：《地震地质》2016年第3期631-645,共15页Seismology and Geology

基　　金：地震科技星火计划项目(XH12037Y)资助

摘　　要：利用海南岛及邻区2000—2012年精定位后的地震S波资料进行Q_s值成像,得到区域Q_s值分布和滑动平均Q_s值变化,结合地震活动、火山、热流点和GPS基线变化分析区域浅层地壳（深5~15km）S波衰减的时空变化特征,并讨论了区域地壳介质应力条件状态变化的特点。结果表明：1）衰减成像结果显示研究区Q_s值空间上横向不均匀变化显著,总体呈现海南岛中部高、周边低的特征,低Q_s值（高衰减）主要分布在王五-文教断裂以北、尖峰-吊罗断裂以南及铺前-清澜断裂以东区域。地震活动多丛集分布在高、低Q_s值过渡区域,火山主要分布在王五-文教断裂以北的雷琼坳陷低Q_s值区域及其附近,大地热流点分布于低Q_s值及其边缘区域。2）滑动平均Q_s值的时间变化特征与地震活动性、泸州—琼中GPS基线变化存在较强的相关性。2000—2008年,研究区地震活动性较强,泸州—琼中GPS基线呈缩短趋势,滑动平均Q_s值相对较高,区域可能处于＂高＂应力介质条件状态;2008—2012年,研究区地震活动性较弱,泸州—琼中GPS基线显示伸长趋势,滑动平均Q_s值相对较低,区域可能处于应力调整、松弛的＂低＂应力介质条件状态。Using double-difference precise location results of seismic S wave data from 2000 to 2012,distribution and variation of dynamic moving average Qsvalue are imaged in Hainan Island and adjacent regions through seismic attenuation tomography. We explore regional crustal S-wave attenuation characteristics of temporal and spatial variation combined with seismic activity,volcanoes and heat distribution,and GPS baseline changes. The results show that：（ 1） Attenuation imaging shows that there is a significant lateral heterogeneity in Qsdistribution in the study area and the Qs values are high in the central region and low in the north and south regions of Hainan Island. Low-Qs areas are baseically converged to the north of Wangwu-Wenjiao Fault,to the south of Jianfeng-Diaoluo Fault,and to the east of Puqian-Qinglan Fault. Earthquakes are basically converged to the edge of the transitional regions of high and low Qsvalues. Heat flow sites and volcanoes zones are located in lowQsarea in the region.（ 2） There is a strong correlation between dynamic moving average Qsvalue,seismic activity and Luzhou-Qiongzhong GPS baseline. From 2000 to 2008,the average Qsvalue of the study area is relatively high,the seismic activity is strong,and Luzhou-Qiongzhong GPS baseline is decreasing. From 2008 to 2012,the average Qsvalue of the study area shows a downward trend,the seismic activity is weak,and the Luzhou-Qiongzhong GPS baseline displays an elongation trend.

关 键 词：Qs成像 地震活动性 火山 热流 GPS基线 海南岛及邻区 

分 类 号：P315.3[天文地球—地震学]