Origin of the Changbai intra plate volcanism in Northeast China: Evidence from seismic tomography  

作　　者：ZHAODapeng LEIJianshe TANGRongyut 

机构地区：[1]GeodynamicsResearchCenter,EhimeUniversity,Matsuyama790-8577,Japan [2]GeodynamicsResearchCenter,EhimeUniversity,Matsuyama790-8577,Japan//InstituteofCrustalDynamics,ChinaSeismologicalBureau,Beijing100085,China [3]InstituteofCrustalDynamics,ChinaSeismologicalBureau,Beijing100085,China

出　　处：《Chinese Science Bulletin》2004年第13期1401-1408,共8页

摘　　要：Seismic images of the mantle beneath the active Changbai intraplate volcano in Northeast China determined by teleseismic travel time tomography are presented. The data are measured at a new seismic network consisting of 19 portable stations and 3 permanent stations. The results show a columnar low-velocity (-3%) anomaly extending to 400 km depth under the Changbai volcano. High velocity anomalies are visible in the mantle transition zone, and deep earthquakes occur at depths of 500--600 km under the region,suggesting that the subducting Pacific slab is stagnant in the transition zone, as imaged clearly also by global tomography.These results suggest that the Changbai intraplate volcano is not a hotspot like Hawaii but a kind of back-arc volcano related to the upwelling of hot asthenospheric materials associated with the deep subduction and stagnancy of the Pacific slab under northeast Asia.Seismic images of the mantle beneath the active Changbai intraplate volcano in Northeast China determined by teleseismic travel time tomography are presented. The data are measured at a new seismic network consisting of 19 portable stations and 3 permanent stations. The results show a columnar low-velocity (-3%) anomaly extending to 400 km depth under the Changbai volcano. High velocity anomalies are visible in the mantle transition zone, and deep earthquakes occur at depths of 500-600 km under the region, suggesting that the subducting Pacific slab is stagnant in the transition zone, as imaged clearly also by global tomography. These results suggest that the Changbai intraplate volcano is not a hotspot like Hawaii but a kind of back-arc volcano related to the upwelling of hot asthenospheric materials associated with the deep subduction and stagnancy of the Pacific slab under northeast Asia.

关 键 词：长白火山 火山作用 内陆板块 中国 东北地区 地震测量 X线断层摄影术 遥测地震学 

分 类 号：P317[天文地球—固体地球物理学]