五大连池地区深部结构探测研究

项目名称： 五大连池地区深部结构探测研究

项目编号： No.41474040

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 艾印双

作者单位： 中国科学院地质与地球物理研究所

项目金额： 148万元

中文摘要： 火山喷发是严重破坏人类社会和自然环境的重大地质灾害。中国虽然缺少现代火山喷发，但是新生代的火山活动相当频繁。五大连池火山群是中国为数不多的有火山喷发文字记载的火山之一，是中国著名的第四纪火山群,也是世界陆内单成因火山的典型代表，对该火山成因及机制还存在着许多争议并提出了多种动力学模型。研究五大连池火山的成因及深部动力学机制的关键还要获得火山下方岩浆房和热物质通道的位置与深部形态。基于目前五大连池地区已有的地震台站分布情况，本项目拟布设一个平均台站间距为50公里的二维地震台阵开展为期两年的观测。利用采集的地震数据并结合该地区已有的地震资料，采用多种地震成像方法获取五大连池及邻近地区的深部地震波速度分布、间断面形态等地震学信息，重点关注低速体分布形态，及其与周围构造块体的深部接触关系。在此基础上，结合地球化学及其它地球物理观测结果，探讨火山活动的深部动力学过程。

中文关键词： 层析成像；接收函数；地震定位；地震台阵；背景噪声

英文摘要： Volcanic eruptions are one of Earth's most dramatic and violent agents of change, can pose a big hazard to humans. Although there were no volcanic eruptions during the recent hundreds of years in China, the volcanism is quite active in Cenozoic time. The Quaternary Wudalianchi volcanoes were recorded to erupt in Chinese history. They are the best examples of the intra-continental monogenetic volcanoes. The mechanism of forming these volcanoes is still under debate. Several dynamic models were proposed to interpret this. The position and shape of the magma chamber and the channels of hot mantle materials play a key role to reveal the mechanism and dynamic processes of the Wudalianchi volcanism. Considering the distribution of seismic arrays deployed by the previous studies, we plan to deploy a 2-D array with the average station interval of 50 km for two year observation in this project. Combining the seismic data recorded by both this array and the previous arrays, we adopt multiple methods of seismic imaging to yield the seismic velocity models and the shapes of seismic discontinuities beneath the Wudalianchi volcanoes and surrounding regions. we focus on the shape of low velocity bulks and their spatial contact with the surrounding blocks. Based on the results of our seismic imaging, we discuss the details about the geodynamic processes of Wudalianchi volcanoes combining with the studies of geochemistry and geophysics.

英文关键词： Seismic tomography;Receiver functions;Seismic location;Seismic array;Ambient seismic noise