长白山天池火山区大地电磁测深初步观测

PRELIMINARY OBSERVATIONS OF THE TIANCHI VOLCANO AREA IN CHANGBAISHAN MOUNTAIN BY MT METHOD

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。

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.