Seismic structure and origin of active intraplate volcanoes in Northeast Asia |
| |
| Authors: | Yonghong Duan Dapeng Zhao Xiankang Zhang Shaohong Xia Zhi Liu Fuyun Wang Li Li |
| |
| Institution: | aGeophysical Exploration Center, China Earthquake Administration, Zhengzhou 450002, China;bDepartment of Geophysics, Tohoku University, Sendai 980-8578, Japan |
| |
| Abstract: | Three-dimensional P-wave velocity structure beneath the Changbai and other intraplate volcanic areas in Northeast Asia is determined by inverting 1378 high-quality P-wave arrival times from 186 teleseismic events recorded by 61 broadband seismic stations. Low-velocity (low-V) anomalies are revealed beneath the Changbai, Longgan, Xianjindao volcanoes. High-velocity (high-V) anomalies are found in the mantle transition zone, where deep-focus earthquakes under Hunchun occur at depths of 500–600 km. The high-V anomaly reflects the deep subduction of the Pacific slab under NE Asia which may have contributed to the formation of the Changbai, Longgang, Xianjindao and Jingpohu intraplate volcanoes. A low-V anomaly is also revealed in the mantle transition zone, which may have a close relationship with the occurrence of deep earthquakes under the Hunchun area. Our results support the Big Mantle Wedge (BMW) model by Zhao et al. Zhao, D., Lei, J., Tang, Y., 2004. Origin of the Changbai volcano in northeast China: evidence from seismic tomography, Chin. Sci. Bull. 49, 1401–1408; Zhao, D., Maruyama, S., Omori, S., 2007. Mantle dynamics of western Pacific and East Asia: insight from seismic tomography and mineral physics. Gondwana Res. 11, 120–131.] who proposed that the intraplate volcanoes in NE Asia are caused by the back-arc magmatism associated with the deep dehydration process of the subducting slab and convective circulation process in the BMW above the stagnant Pacific slab. |
| |
| Keywords: | P-wave velocity structure Teleseismic tomography Changbai volcano Stagnant Pacific slab Hunchun deep earthquakes |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
