五大连池火山区地壳岩浆囊的密集台阵地震成像研究

火山活动是地球内部物质运移的重要方式，火山岩浆囊在地壳内部的空间分布、规模及熔融程度是地震学等地球物理研究的重要内容。五大连池火山作为典型板内火山，已经发现上地壳岩浆囊存在的证据。但受限于已有地震台阵较为稀疏，且未能覆盖整个五大连池14座火山，仍然有一些重要问题尚未解决。例如，五大连池14座火山中，还有哪些火山存在上地壳岩浆囊？在什么深度范围？考虑到板内火山可在上地壳和下地壳形成单独岩浆囊，五大连池火山区下地壳是否存在一个或几个大的岩浆囊？其与上地壳岩浆囊之间存在何种联系？为回答上述问题，本申请拟利用由179台三分量短周期地震仪组成的密集台阵，使用地震面波频散和接收函数全局优化联合反演方法，获得五大连池火山区地壳尺度三维S波精细结构，研究整个地壳内部岩浆囊空间分布、规模及熔融比例等特征，为深入认识五大连池火山形成与演化机理、评估火山喷发风险以及板内火山相关的深部构造和动力学机制提供参考。

Volcano activity is the important way for mass migration in the Earth. The spatial distribution, volume and partial melting percentage of magma chambers is an important task for seismic and geophysical imaging. As one of the typical intraplate volcanoes, upper crust magma chamber has been found beneath the Wudalianchi volcano. However, limited by the sparse seismic stations, and the limited coverage for whole volcano field, there are still some important problems unresolved. For example, are there any more upper crust magma chambers beneath 14 volcanoes in Wudalianchi? What's the depth scale? Considering that magma chambers can be formed both inside the upper crust and the lower crust, is there one or more large-scale magma chambers inside the lower crust? If so, what’s the relations between the magma chambers in the lower crust and upper crust? In order to answer above questions, we utilize dense seismic array with 179 short-period, three-component seismometers and the joint inversion of surface wave dispersions and receiver function waveforms to image the high-resolution, three-dimensional velocity structure of the whole crust beneath the Wudalianchi volcano. The magma chambers in the whole crust can be well investigated, including the spatial distributions, volume and partial melting percentages. This study can promote the understanding of the mechanism of volcanic formation and evolution, evaluation of volcanic eruption risk, related deep tectonics and geodynamics of intraplate volcano.