江苏射阳地区地震尾波Q_c值特征

选取2009—2018年江苏省射阳地震台200 km范围内M_L≥2.0地震波形资料,基于Sato单次散射模型,计算该区域S波尾波Q_c值,并探求其时间变化特征。采用相同方法计算盐城、灌云地震台地震波形资料尾波Q_c值,并将3个地震台的计算结果进行对比。结果表明:射阳地区是江苏省尾波Q_0低值区域,Q_c值随频率的变化关系为Q_c(f)=33.7±3.4f ~(1.16±0.04);在2016年10月20日射阳M_(L )4.8地震前,射阳地区尾波Q_c值有增大现象,Q_c值变化特征表现为上升—下降—上升—发震;盐城、射阳、灌云地震台所记录地震的尾波Q_c值在震前均出现明显的高值异常变化。     

Three-dimensional P-wave velocity structure of the crust beneath Hainan Island and its adjacent regions, China

Using over 3 500 first P arrival times recorded by nine digital seismic stations from Hainan Digital Seismic Net-work during 1999～2005,a 3-D P-wave velocity model of the crust under Hainan Island and adjacent regions has been determined. The results show that the pattern of velocity anomalies in the shallower upper crust is somewhat associated with the surface geological tectonics in the region. A relative low-velocity anomaly appears north of the Wangwu-Wenjiao fault zone and a relative high-velocity anomaly appears south of the Wangwu-Wenjiao fault zone,corresponding to the depressed areas in north Hainan Island,where many volcanoes are frequently active and geothermal values are relatively higher,and the uplifted and stable regions in central and south of the Hainan Is-land. In the middle and lower crust velocities are relatively lower in east Hainan than those in west Hainan,possi-bly suggesting the existence of the upwelling of hot materials from the mantle in east Hainan. The pattern of veloc-ity anomalies also indicates that NW faults,i.e.,the Puqian-Qinglan fault,may be shallower,while the E-W Wangwu-Wenjiao fault may be deeper,which perhaps extends down to Moho depth or deeper.     

贵州岩溶地下水开发与经济技术评价

贵州省岩溶发育强烈,导致地表水严重漏失和石漠化加剧,岩溶石山区可供开发利用地表水资源严重短缺,工程性缺水尤为明显.本文分析表明,贵州地下蕴藏较丰富的地下水资源,可供开发利用的资源有保障,开发潜力大,前景好,特别是对解决省内分散性居住的广大农村缺水问题.地下水的开发具有投资省、水量稳定、水质好、投资回收快、改善生态环境等优点,是对地表水供水不足的有效补充,从社会效益、经济效益、还是环境效益上,岩溶地下水的开发均有着显著的优势.