World Tsunamis: History and Impact Tsunamis are natural phenomena that arise as a result of massive dislocations, such as earthquakes on the sea floor, volcanic eruptions, or underwater landslides. In history, tsunamis have caused enormous damage and claimed many lives. One of the most famous tsunamis occurred on December 26, 2004, which hit the waters of the Indian Ocean, impacting countries such as Indonesia, Thailand and Sri Lanka. The 2004 event began with an earthquake measuring 9.1 on the Richter scale, which was one of the largest ever recorded. The resulting tsunami waves reached up to 30 meters in some places, approaching land at speeds of up to 800 km/hour. Within minutes, coastal areas in various countries were hit by powerful waves, damaging infrastructure and causing material losses reaching billions of dollars. Countless people have been forced to lose their homes, families and livelihoods. Before the 2004 tsunami, tsunami events were also recorded in history, such as the 1700 tsunami in Cascadia, which was caused by an earthquake in the tectonic plates. However, the impact and consequences of these events are often unmeasurable due to technological limitations and inadequate record-keeping. The impact of a tsunami is not only physical, but also emotional and psychological. Survivors often face profound trauma, loss of loved ones, and damage to assets and infrastructure. Post-tsunami response often involves international assistance, in the form of food, clean water and medical treatment, but long-term improvements such as economic recovery take longer. On the other hand, the tsunami also encouraged the development of better crisis prediction and response technology. After the 2004 tsunami, many countries, including Indonesia, developed more efficient tsunami early warning systems. This system combines underwater sensors with modern communications technology to provide early notification to residents living in tsunami-prone areas. Additionally, research and education about tsunamis is becoming more important. Community training and outreach programs, especially those in coastal areas, are very important to minimize impacts in the future. Awareness of the natural signs that may indicate a tsunami could save many lives. Ecosystem rehabilitation is also an important component after the tsunami. Restoring damaged ecosystems, such as mangroves and coral reefs, not only helps nature recover, but also strengthens coastal protection from future extreme waves. From all these aspects, it is clear that the tsunami not only affected the physical and environmental aspects, but also the social and economic aspects of local communities. Effective preparedness and recovery requires cooperation from all parties, from government to local communities. This event shows how important awareness and understanding of natural disasters is so that future generations can be prepared to face the same challenges.