Can A Volcano Trigger A Tsunami? Exploring The Volcanic-Tsunami Connection

Volcanoes can occasionally trigger tsunamis through slope instabilities, although such events are relatively rare in the grand scheme of tsunami occurrences. Since the 17th century, records indicate that approximately 1% of observed tsunamis have been linked to volcanic slope instabilities. Notable historical instances of tsunamis resulting from slope instabilities include the events at Hokkaido Koma-ga-take in 1640, Mount Unzen in 1792, Augustine Volcano in 1883, Ritter Island in 1888, Paluweh in 1928, and Iliwerung in 1979. These occurrences shed light on the infrequent but significant impact that volcanic activity can have on generating tsunamis. Additional research and monitoring are essential to better understand and mitigate the potential risks associated with volcanic-induced tsunamis.

Tsunamis, powerful and destructive ocean waves, result from a variety of natural events that trigger significant seafloor disturbances. These disturbances can take the form of seismic activity, such as earthquakes, where the Earth’s tectonic plates shift abruptly beneath the ocean’s surface. Additionally, tsunamis can be initiated by the sudden displacement of large volumes of earth and rock, as seen in landslides or the collapse of underwater mountains known as seamounts. Another contributor to tsunami formation is the introduction of molten lava into the ocean, creating explosive interactions. Furthermore, though relatively rare, tsunamis can also be generated by the impact of meteorites striking the Earth’s surface. Understanding these five primary causes of tsunamis is crucial for assessing and mitigating the associated risks to coastal communities and ecosystems.

Are volcanic tsunamis considered rare occurrences? To shed light on their frequency, it’s important to note that volcanic tsunamis are relatively infrequent events. When we examine historical records spanning the 19th and 20th centuries, we find that humanity has encountered only a limited number of these events, totaling approximately 90 to 100 instances in that span. This figure becomes more meaningful when we compare it to the annual average of volcanic eruptions, which typically ranges between 60 and 80 eruptions per year. Therefore, the occurrence of volcanic tsunamis appears to be roughly equivalent in frequency to the number of volcanic eruptions that happen in a given year. This information provides valuable context for understanding the rarity of volcanic tsunamis in our world. (Updated as of September 1, 2023)