13:45 〜 15:15
[SEM14-P03] Magnetic three-component inversion using the total field data as the input.
キーワード：磁気インバージョン、磁場ベクトル、磁化ベクトル
In the conventional magnetic inversion, the magnetic total field is used as the input data, and the distribution of the magnetization intensity is determined with fixing the magnetization direction of the subsurface structure.
In such studies, magnetization direction is assumed to be parallel with that of the current geomagnetic field. This is because the subsurface magnetization is assumed to be the induced magnetization. However, especially in the volcanic region, remanent magnetization of the subsurface rock is important and interest factor, and in this case, magnetization direction is not always parallel with that of the geomagnetic field. Therefore, for the magnetic inversion in the volcanic region, not only the magnetization intensity of the subsurface rock but also their direction have to be determined.
For this purpose, we arrange the inversion scheme to determin the three component of the magnetization vector (intensity, declination, and inclination) of the subsurface rock. In this scheme, magnetic three component data is nessesary, and thus, we also arrange a scheme to estimate the magnetic three component from the total field based on the potential theory.
This three component inversion is non-linear, and we have to solve it in iteratively. This iteration is based on the Gauss-Seidel method, and is also introduced the sparse regularization (L1 norm regularization). In our presentation, we will describe our scheme in detail and present the results of the synthetic tests.
In such studies, magnetization direction is assumed to be parallel with that of the current geomagnetic field. This is because the subsurface magnetization is assumed to be the induced magnetization. However, especially in the volcanic region, remanent magnetization of the subsurface rock is important and interest factor, and in this case, magnetization direction is not always parallel with that of the geomagnetic field. Therefore, for the magnetic inversion in the volcanic region, not only the magnetization intensity of the subsurface rock but also their direction have to be determined.
For this purpose, we arrange the inversion scheme to determin the three component of the magnetization vector (intensity, declination, and inclination) of the subsurface rock. In this scheme, magnetic three component data is nessesary, and thus, we also arrange a scheme to estimate the magnetic three component from the total field based on the potential theory.
This three component inversion is non-linear, and we have to solve it in iteratively. This iteration is based on the Gauss-Seidel method, and is also introduced the sparse regularization (L1 norm regularization). In our presentation, we will describe our scheme in detail and present the results of the synthetic tests.