背景噪声面波与大地电磁三维联合反演研究及其在五大连池火山地区的应用

在利用不同的地球物理勘探方法对地下复杂结构成像时，因观测系统的非完备性及数据本身对某些岩石物性的不敏感性，单独成像的结果存在较大的不确定性和不一致性。为解决单一地球物理数据成像存在的问题，基于不同地球物理效应由相同异常体引起，同时不同地球物理数据所反映的属性结构相似的特点，本项目开展基于交叉梯度结构一致性约束的背景噪声面波数据与大地电磁数据的联合反演研究，发展结构一致性约束的联合反演方法，即在满足各自数据拟合的基础上，速度结构与电阻率结构互相约束，得到更准确的速度与电阻率结构。然后，把新的联合反演方法应用到五大连池尾山地区的联合成像中，获得尾山火山锥下方更可靠的速度结构与电阻率结构。为研究该区域地热资源分布、岩浆通道等火山地质构造、火山喷发灾害预测、火山地球物理学研究提供支持。

In the use of different geophysical exploration methods for underground complex structure imaging, due to the imperfection of the observation system and the data itself is not sensitive to some petro-physical properties, the results of the single imaging there is a large uncertainty and inconsistency. In order to solve the problem of separate geophysical data inversion, based on the different geophysical effects caused by the same anomaly, and different geophysical data reflect the characteristics of similar the structure with different properties, the project carried out the study of joint inversion of ambient noise surface wave data and magnetotelluric data with structure similarity based on cross-gradient, and develop the joint inversion strategy with structure consistence. On the basis of satisfying the data fitting respectively, obtain more accurate velocity and resistivity model by making the structure constraint mutually between velocity model and resistivity model. Then, apply the new joint inversion strategy to the Wudalianchi Weishan mountain area, and obtain the more reliable velocity structure and resistivity structure below the Weishan Mountain. It will provides support for the study of volcanic geological structure, volcanic eruption disaster prediction and volcanic geophysics.