Global Volcanism Program | Image GVP-10585
The 11-km-wide Towada caldera, seen here from the E, formed during as many as six major explosive eruptions over a 40,000-year period ending about 13,000 years ago. The two peninsulas extending into the caldera lake are the rims of Nakanoumi caldera, truncating Goshikiiwa volcano in the SSE section of the caldera. The rounded lava dome that was constructed at the tip of lower peninsula is Ogurayama, the source of the 915 CE eruption.
Copyrighted photo by Yoshihiro Ishizuka (Japanese Quaternary Volcanoes database, RIODB, http://riodb02.ibase.aist.go.jp/strata/VOL_JP/EN/index.htm and Geol Surv Japan, AIST, http://www.gsj.jp/).