MAGNETIZATION OF ASO VOLCANO

Abstract

To investigate the status of the magnetization of Aso Volcano, Geomagnetic surveys at Aso volcanic region have been done for many years. From these results we found the two kinds of geomagnetic anomalies, i. e., one is the general magnetization of Aso Caldera and the other is the local anomaly which is classified into the several limitted places. In this paper the scale and the orientation of the rock-body which causes this general magnetization of Aso Caldera will be discussed, and it is concluded that this seems to be situated just underside the ground-level of Aso Caldera. Under an assumption that a shape of this rock-body is a rotational ellipsoid, the observational results have been compared with the calculated values.