地質陰影図（南西→北東、30°）。山頂部南西側に広がる文化溶岩･火砕丘（紫色）は1813年の噴出物。その噴火の末期に東側に開いた作地カルデラが形成された。カルデラ内の明治溶岩（赤色）は1884-85年の噴出物。

Topographic relief of Suwanosejima combined with geological map (tilted by 30° from the SW to the NE). The Bunka pyroclastics and lavas (purple-colored) are distributed around from the summit area to the western coast. The youngest lava, Meiji Lava (red-colored), erupted in 1884-85 is distributed inside the Sakuchi Caldera which was formed at the end of 1813 eruption (Bunka Eruption).