Usu rises at the right across Lake Toya with the Nakanojima lava dome complex at the left forming an island in the caldera lake. The light-colored area in the bottom half of this 12 August 1977 photo is floating pumice produced by explosive eruptions of Usu during 7-9 August.

Photo by Lee Siebert, 1977 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Keywords: pumice | lava dome | crater lake | caldera

Toya