A tsunami originating from a far away source, generally more than 1,000 km or more than 3 hours tsunami travel time from its source.

Less frequent, but more hazardous than regional tsunamis, are ocean-wide or distant tsunamis. Usually starting as a local tsunami that causes extensive destruction near the source, these waves continue to travel across an entire ocean basin with sufficient energy to cause additional casualties and destruction on shores more than a 1,000 kilometres from the source. In the last 200 years, there have been at least 28 destructive ocean- wide tsunamis and 14 have caused fatalities more than 1,000 kilometres from the source.

The most destructive Pacific-wide tsunami of recent history was generated by a massive earthquake off the coast of chile on 22 may 1960. all chilean coastal towns between the 36th and 44th parallels were either destroyed or heavily damaged by the action of the tsunami and the earthquake. The combined tsunami and earthquake toll included 2,000 killed, 3,000 injured, two million homeless, and $550 million damage. off the coast of corral, chile, the waves were estimated to be 20 metres (67 feet) high. The tsunami caused 61 deaths in Hawaii, 20 in the Philippines, and 139 in Japan. estimated damages were $50 million in Japan, $24 million in Hawaii and several millions of dollars along the west coast of the United states and canada. Distant wave heights varied from slight oscillations in some areas to 12 metres (40 feet) at Pitcairn Island, 11 metres (37 feet) at Hilo, Hawaii, and 6 metres (20 feet) at some places in Japan.

The worst tsunami catastrophe in history occurred in the Indian Ocean on 26 December 2004, when a M9.3 earthquake off of the northwest coast of Sumatra, Indonesia, produced an ocean-wide tsunami that hit Thailand and Malaysia to the east, and Sri Lanka, India, the Maldives, and Africa to the west as it traversed across the Indian Ocean. Nearly 228,000 people lost their lives and more than a million people were displaced, losing their homes, property, and their livelihoods. The magnitude of death and destructiveness caused immediate response by the world’s leaders and led to the development of the Indian Ocean Tsunami Warning and Mitigation System in 2005. The event also raised awareness of tsunami hazards globally, and new systems were established in the Caribbean, the Mediterranean and Atlantic.