Structure of Northeastern Sakurajima, South Kyushu, Japan, Revealed by Seismic Reflection Survey(＜Special Section＞Sakurajima Special Issue)

Abstract

Seismic reflection structure in the northeast part of Sakurajima Volcano is discussed down to ca. 11 km with three profiles. Data acquisition was conducted along intersecting two lines with 221 stations and eight shot points. The two lines covered the northeastern portion of the volcano. One of the lines was spread along NNW to SSE direction in the east foot, and another line was oriented east to west in the northern flank of the volcano. Data processing were made through the conventional procedure of the reflection seismology, and depth migrated sections were obtained. Four continuous reflection horizons appear in the profiles. One of the reflection horizons around 5.4 km depth disappears in the northeast portion of the coverage area. The interruption of the horizon suggests existence of magma or magma supply path beneath it. The inferred magma supply path locates to the west of that previously presented.