In recent years, a number of disasters caused by earthquakes have demonstrated the vulnerability of both the developing and the developed world. This book provides new research on earthquakes. Chapter One focuses on the behavior of a simple spring-block model from the viewpoint of nonlinear dynamics and seismology. Chapter Two employs a new technique based on Extreme Learning Machine (ELM) for determination of liquefaction susceptibility of soil based on Standard Penetration Test (SPT) and Cone Penetration Test (CPT) from the Chi-Chi earthquake. Chapter Three presents a review of earthquake phenomenon in Nigeria, the occurrence and available data. Chapter Four describes the behavior and failure mechanisms of unreinforced masonry buildings and different rehabilitation and strengthening techniques. Chapter Five presents the results related to the preferred sources of information related to Risk, Hazard and Natural disaster. Chapter Six presents results regarding urban and semi-rural schoolchildren's seismic risk perception, awareness and preparedness of a highly seismic region, in the state of Oaxaca, Mexico. Chapter Seven reviews the anomalous decrease in groundwater radon before the Taiwan large earthquakes.