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...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.展开更多
中国大陆有很多火山，如我国东北五大莲池、长白山和西南地区腾冲火山以及最南部的海南火山等。其中前三者均被认为是活火山（刘嘉祺，1999；刘若新，2000），是与太平洋板块和缅甸弧板块的俯冲与脱水密切相关的弧后火山（Zhao et al．...中国大陆有很多火山，如我国东北五大莲池、长白山和西南地区腾冲火山以及最南部的海南火山等。其中前三者均被认为是活火山（刘嘉祺，1999；刘若新，2000），是与太平洋板块和缅甸弧板块的俯冲与脱水密切相关的弧后火山（Zhao et al．，2004；Lei and Zhao，2005；Huang arid Zhao，2006）。然而，海南火山被认为是一种热点火山（e．g．，Montelli et al．，2006），是一种与夏威夷热点相类似板内热点火山（Lei andZhao，2006）。展开更多
基金The special project of Detection of Haikou City Earthquake Active Faults from the Tenth Five-year Plan of China Earthquake Administration (0106512)Joint Seismological Science Foundation of China (105086)CAS Key Laboratory of Marginal Sea Geology (MSGL0503).
文摘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.
文摘中国大陆有很多火山，如我国东北五大莲池、长白山和西南地区腾冲火山以及最南部的海南火山等。其中前三者均被认为是活火山（刘嘉祺，1999；刘若新，2000），是与太平洋板块和缅甸弧板块的俯冲与脱水密切相关的弧后火山（Zhao et al．，2004；Lei and Zhao，2005；Huang arid Zhao，2006）。然而，海南火山被认为是一种热点火山（e．g．，Montelli et al．，2006），是一种与夏威夷热点相类似板内热点火山（Lei andZhao，2006）。
