Tsunami are among the most destructive natural disasters on the Earth. They are most often caused by tectonic movements of the tectonic plates on the ocean floor. The largest occurrences of this nature is an anomaly in the Pacific Ocean, Japan, Indonesia and the Indian Ocean. However, the risk of tsunami threatens to virtually all coastal areas of the world. Among the most destructive disaster caused by the tsunami in the 21st century clearly belongs tsunami that struck the coast of Southeast Asia (Thailand, India, Malaysia, Bangladesh, Maldives ...) a little later Madagascar, the Seychelles and the east coast of Africa, where there are states like Somalia , Tanzania or Kenya. And so it is possible that one will hit the Brazilian coast and Rio de Janiero.