Abstract: Observations by magnetotelluric technique have been carried out at 15 sites along two profiles in Tianchi volcano area of Changbaishan Mountain northeast China. The impedance tensor decomposition and a new two-dimensional inversion method (RRI) are used for data analysis and interpretation. The results show that the conductivity structure beneath the volcano and its neighbouring area is of two-dimensional character and a local three-dimensional low resistivity body exists at depth of about 12km under the volcano. It is inferred that this anomaly body may be a magma chamber.

摘要： 在长白山火山区沿着两条剖面进行了15个测点的大地电磁测深观测,对地磁感应矢量和地下电性分布维数特征进行了分析,并使用阻抗张量分解和二维自动反演等新技术对资料进行了解释。结果表明,火山区及其周围地区的地下电性结构具有二维特征,但在火山口及其附近地下存在局部三维异常体,异常体埋深约12km,初步推测可能是火山岩浆囊。

关键词: 火山, 大地电磁测深, 电阻率, 阻抗张量, 岩浆囊