五大连池火山区地壳上地幔速度结构的接收函数反演

THE VELOCITY STRUCTURE OF CRUST AND UPPER MANTLE IN THE WUDALIANCHI VOLCANO AREA INFE-RRED FROM THE RECEIVER FUNCTION

五大连池火山是全新世以来曾经喷发的近代火山群,该火山区小震活动频繁,被认为足“活动”的休眠火山。本文对该火山区的深部结构进行了接收函数反演和研究。研究结果表明:该火山区存在广泛分布的S波低速结构,个别低速结构赋存部位较浅,低速结构与地震活动性具有对应关系,火山区下部的莫霍界面不十分明显,存在岩浆上涌的条件。因此,我们认为该火山具有活动火山的深部结构特征,存在再次活动的基本条件。

The Wudalianchi volcano is a modern volcano erupted since the Holocene. Its frequent occurrence of the small earthquake is considered to be indicator of active dormancy volcano. The S wave velocity structure is inferred from the receiver function for the crust and upper mantle of the Wudalianchi volcano area. The results show that the low velocity structure of S wave is widely distributed underneath the volcano area and part of the low-velocity-zone located at shallow depth in the Wudalianchi volcano area. The low velocity structure is related to the seismicity. The Moho interface is not clear underneath the volcano area, which may be regard to be an nec-essary condition for the lava upwelling. Therefore, we infer that the Wudalianchi volcano has the deep structural condition for the volcano activity and may be alive again.