Global Volcanism Program | Image GVP-00539
The steep wall behind Tomok village on Samosir Island is part of a block of uplifted caldera-fill rocks. The entire 630 km2 island, which now rises to 700 m above Lake Toba, is capped with lake-floor sediments that were deposited before the island was uplifted above lake level.
Photo by Tom Casadevall, 1987 (U.S. Geological Survey)
This image is made available as a Public Domain Work, but proper attribution is appreciated.