Tephra deposits are layers of volcanic material ejected during explosive eruptions. They consist of fragments of rock, ash, and volcanic glass that can vary in size from fine dust to large boulders. These deposits can cover large areas and are important for understanding past volcanic activity and its impact on the environment. The study of tephra deposits helps scientists reconstruct eruption histories and assess potential hazards. By analyzing the composition and distribution of these materials, researchers can gain insights into the behavior of volcanoes and the effects of eruptions on surrounding ecosystems and human populations.