Cross-Section of Mt. Sanbe’s Volcanic Deposits

Cross-Section of Mt. Sanbe’s Volcanic Deposits

This remarkable wall is actually a cross-section of earth from the grassland west of Mt. Sanbe. The section measures 8 meters wide and 10 meters tall, and its many strata (layers) provide a visual representation of the last 20,000 years of Sanbe’s eruptive history.
Sanbe’s different eruptive phases are clearly visible in the divisions of the strata. The pale layers were formed from volcanic products and pyroclastic materials—namely, ash, sand, and pumice—that were spewed into the air during phases of volcanic activity. Rain and wind spread this material over a wide area before it settled. The black strata represent Sanbe’s inactive periods, when soil, leaves, and other organic matter accumulated on top of previously deposited volcanic material.
This exhibit shows less than a fifth of Sanbe’s 100,000-year history. Seeing how eruptions from even this small portion of the volcano’s active life have visibly reshaped the landscape, it is possible to envision how volcanoes like Sanbe have transformed entire regions.