选取广东省东部及福建和江西测震台网的26个固定台站2011年3～9月的地震背景噪声的垂直分量数据,用互相关方法获得瑞利面波的格林函数,再用频时分析方法提取瑞利面波的群速度频散曲线,最后用面波层析成像方法反演得到研究区周期为5～15s的瑞利面波群速度图像。反演结果揭示了广东省东部地区浅部地壳群速度结构存在明显横向不均匀性。短周期群速度异常与研究区内山脉、盆地的分布有较好的对应关系,沉积厚度较大的盆地地区表现为低速异常,而基底埋深较浅的山脉则显示了高速异常;地热分布对面波群速度产生重要影响,地热值较高的区域面波群速度一般表现为低速异常;粤东地区特别是粤东沿海地区地壳中部可能存在低速层。

We have inverted for the Rayleigh wave group velocity distribution of east region of Guangdong Province at periods of 5 ～ 14s using vertical component of ambient seismic noise tomography. Seven months continuous data （March to September, 2011 ） used in this study are from 26 permanent seismic stations of the Guangdong Regional Seismic Network and its adjacent stations in Fujian and Jiangxi Provinces. Green＇s functions were first extracted from crosscorrelations of data at adjacent stations and group velocity dispersion measurements were then made using the frequency-time analysis method. Our results show significant lateral variations in uppermost crustal structures of the region. Group velocity anomalies at short periods correlate well with the surface geology of basins and mountains. The slow velocity anomaly at basin area suggests a rather thick sediment deposit, and the high velocity anomaly at mountains suggests a shallow buried depth of basement. Geothermal was an important impact factor for group velocity, and the slow velocity anomaly generally correlate with the area of high geothermal. A low-velocity layer may exist in the middle crust in the eastern region of Guangdong, especially in the coastal area of the region.[著者文摘]

中国地震局2011年度震情跟踪合同制项目（2011020105）与地震动力学国家重点实验室开放基金课题（LED2011Bcl4）资助