音波データ解析による中海湖底下の大根島火山の広がりと三次元可視化

The subsurface distribution of the Daikonjima basalt in Lake Nakaumi was examined by a series of echo sounding data from SH-10，SH-20，Chirp Sonar and Bubble Pulser，most of which have been obtained by the efforts of Shimane University members．The Daikonjima volcano is now recognized by drilling data as a subaerially erupted volcano around 200 ky in age，the thickness of which extends to 60 meters below sea level．On the basis of analysing echo sounding and drilling data，the Daikonjima Volcano in Lake Nakaumi is successfully reconstructed，and 3D contour and 3D polygon maps are developed．It is apparent that the Daikonjima Volcano extends further under Lake Nakaumi than previously envisaged．