Fig. 5: Configuration and results of modeling deformation during caldera collapse.
From: Magma chamber decompression during explosive caldera-forming eruption of Aira caldera
a Outline of the configuration of the model. A cylindrical magma chamber with a horizontal diameter of 14 km and a vertical length of 3 km at the depth of 7 km from the ground surface is assumed for the simulation. The magma chamber is centered on the center of the Aira caldera. Broken red line shows the projection of the magma chamber to the present sea level. Broken blue line is the current topographic caldera rim. b Calculated vertical displacement of ground surface at the end of the eruption of the Osumi pumice fall due to the 40-km3 extraction of magma from a magma chamber beneath the Aira caldera. The minus sign indicates subsidence. The contour interval is −10 m. Broken red line and blue line mark the projection of the magma chamber to the present sea level, and the topographic caldera rim, respectively. White solid line shows the current coastline. c The vertical displacement profile as a function of the distance from the deformation center after the extraction of magma from the chamber with a volume of (dashed and dotted) 10, (dotted) 20, and (solid) 40 km3. The inverted triangles mark the distance corresponding to the perimeter of the magma chamber.
