火山性地殻変動

抄録

The volcanic crustal deformation is classified into two types: One is the parmanent deformation as the topographic change caused by the eruption, and another is the changeable deformation according to the change of the underground state. Generally, the magnitude of the parmanent deformation is remarkable and visible, although its area is limited. Otherwise, the magnitude of the changeable deformation is smaller than the former, but the dimension of its area sometimes amount to several ten km in diameter as shown in great Sakurajima eruption. Such changeable deformation gives us the useful informations for the volcanic activity. In this paper, some interpretations for the changeable deformation in Sakurajima volcano are introduced, and also some discussions for the abnormal tilt of the ground surface before the eruption in various volcanoes are tried.