This encyclopaedia presents an in-depth and authoritative examination of earthquakes and volcanic eruptions within major seismic belt regions of the world. It brings together historical analysis, geological evidence, and predictive scientific frameworks to explain the dynamics of seismic activity and volcanic behaviour. The book explores tectonic processes, magma evolution, fault systems, and earthquake propagation while also addressing the human, social, and political dimensions of natural hazards. Emphasis is placed on risk perception, preparedness, disaster governance, international response mechanisms, and post-disaster reconstruction challenges. Global case studies illustrate how seismic and volcanic events shape landscapes, economies, and communities over time. This encyclopaedia serves as a comprehensive reference for understanding past events and improving future prediction and management strategies, making it valuable for researchers, policy planners, educators, and advanced students in geology, disaster studies, and environmental sciences.