A tsunami is a series of waves most frequently caused by an earthquake under the sea floor. Tsunamis can cause great loss of life and property damage in coastal areas. Very large tsunamis can cause damage to coastal regions thousands of miles away from the earthquake that caused them. In recent years, world has experienced few mega-tsunamis, which have caused extensive loss of life and properties. The most destructive ones were in December 2004 in Sumatra causing more than 290,000 death and March 2011 in Japan, creating a nuclear accident. The event of 2004 has triggered many global initiatives, such as a new tsunami detection system, more detail coastal modeling, tsunami compatible coastal developments, integrated approach for regional early warning system (EWS) and public educations, awareness and preparedness. The recent advances in tsunami study has lead the scientist for better understanding of the cause of tsunami, its propagation and most importantly the system of warning ahead of tsunami arrival to the vulnerable coastal area. In addition, now the secondary sources for strengthening the devastating effect of the tsunami, for example, the splay faulting, landslide caused by the parent earthquake sources, have been advancing. This book ‘Tsunamis’ shows the state-of-the-art of tsunami research at different levels. The content of the book consists of information on tsunami propagation from the open sea to the coast and coastal tsunami warning system. It includes tsunami propagation, preliminary methods for evaluating the suitability of radar sites for tsunami detection using simulated tsunami velocities and factors affecting tsunami detectability are discussed and methods for reducing the false alarms are described. It also includes the effects of tsunami hazard on the coastal environment and infrastructure. The various contributions cover an array of themes that span from geological evidence to post-trauma human care, encompassing pre-tsunami analyses and modeling to post-tsunami management and preparedness techniques. The chapters are contributed by renowned experts involved in tsunami study for the purpose of covering its different aspects from generation to warning system to be applied in tsunami risk reduction.