A tsunami capable of destruction in a particular geographic region, generally within 1,000 km or 1-3 hours tsunami travel time from its source. Regional tsunamis also occasionally have very limited and localized effects outside the region.
Most destructive tsunami can be classified as local or regional. It follows many tsunami related casualties and considerable property damage also comes from these tsunamis. Between 1980 and 2017 there were 34 local or regional tsunamis that resulted in nearly 252,000 deaths and billions of dollars in property damage; 24 of these were in the Pacific and adjacent seas.
For example, in the Pacific, a regional tsunami in 1983 in the Sea of Japan severely damaged coastal areas of Japan, Korea, and Russia causing more than $800 million in damage, and more than 100 deaths. Then, after nine years with only one event causing one fatality, 10 locally destructive tsunamis occurred in just a seven-year period from 1992 to 1998, resulting in over 2,700 deaths and hundreds of millions of dollars in property damage. In most of these cases, tsunami mitigation efforts in place at the time were unable to prevent significant damage and loss of life. However, losses from future local or regional tsunamis can be reduced if a denser network of warning centres, seismic and water-level reporting stations, and better communications are established to provide a timely warning, and if better programmes of tsunami preparedness and education can be put in place.
The four images above show confirmed tsunami source locations in the Pacific Ocean, Indian Ocean, Mediterranean Sea, and Caribbean Sea. The symbols indicate cause of the tsunami: Brown Square is a landslide, Red Triangle is a volcanic eruption, Question Mark is an unknown cause, and White Circle is an earthquake and the size of the circle is graduated to indicate the earthquake magnitude. Source: NCEI/WDS-Geophysics.
More than 80% of the world’s tsunamis were caused by earthquakes and over 70% of these were observed in the Pacific where large earthquakes occur as tectonic plates are subducted along the Pacific Ring of Fire. Top: Epicentre of all tsunamigenic earthquakes tsunamis have caused damage locally in all ocean basins. Middle: Locations of earthquakes, volcanic eruptions, and landslides generating tsunamis that caused damage or casualties locally. Although the majority of tsunamis that were observed more than 1,000 km away (teletsunamis) were generated by earthquakes in the Pacific, teletsunamis have also caused damage and casualties in the Indian and Atlantic oceans. Bottom: Source locations of teletsunamis generated by earthquakes or volcanic eruptions causing damage or casualties. These data are based on historical records. Source: NGDC / WDS-Geophysics.
