World Tsunamis: Understanding a Deadly Natural Phenomenon Tsunamis are giant ocean waves caused by large shifts in the ocean floor, such as earthquakes, volcanic eruptions, or landslides. This phenomenon can move at speeds of more than 800 km/hour and reach a height of several tens of meters when approaching the coast. With the potential to cause widespread damage, tsunamis are one of the deadliest natural disasters. Various types of tsunamis can occur, such as local tsunamis that arise due to earthquakes near the coast, and long-range tsunamis that can reach thousands of kilometers. People living in coastal areas must understand these dangers, including warning signs such as sudden withdrawals of sea water. Early warning systems are very important in reducing the risk of tsunamis. Modern technology such as seismographs and Pacific bouys are able to detect earth vibrations and sea level changes in real-time. In Indonesia, which is located on the Pacific Ring of Fire, disaster mitigation efforts are increasingly being enhanced through community training and knowledge. Education about tsunamis should be included in local curricula. Coastal residents need to know how to react and evacuate when a tsunami occurs. Mobile applications have also been developed to provide information and warnings to the public quickly. History records many large tsunamis, such as the 2004 Aceh Tsunami which killed more than 230,000 people. This incident shows how vulnerable coastal areas are to the threat of tsunamis. Through historical data, scientists can develop predictive models that help understand patterns and increase awareness. Tsunamis also affect marine and land ecosystems. Affected areas often experience habitat destruction, water contamination, and changes in soil quality. The reconstruction process requires a long time and large resources. Tsunami preparedness involves collaboration between government, non-government organizations and the community. Regular evacuation drill scenarios are important to increase awareness and preparedness. An easily accessible community information dashboard also helps the public to stay informed regarding potential risks. The psychological impact of tsunamis is often ignored. Traumatic events can cause mental health problems such as PTSD. Therefore, psychological support must be integrated into post-tsunami recovery programs. Technology and research continues to develop to prevent losses due to tsunamis. Geophysical research, as well as the development of detection tools and warning systems, are important investments for the future. With a better understanding of tsunamis, communities can not only protect themselves but also contribute to broader mitigation efforts. International competition and collaboration in tsunami management is also increasing. The exchange of information and technology, as well as learning from various global tsunami events, has made the international community more responsive and empowered.