Historically, volcanoes cause 4.6% of tsunami and 9.1% of the deaths attributable to this hazard, totaling 41,002 people. Two events caused this disproportionately large death toll: the Krakatau eruption (Figure 7.1) of August 26–27, 1883 (36,000 deaths) and the Unzen, Japanese eruption of May 21, 1792 (4,300 deaths). Tsunami account for 20%-25% of the deaths attributable to volcanic eruptions. The eruption of Santorini around 1470 bc is not included in these statistics because of a lack of written record. Santorini and the Krakatau eruption of 1883 will be discussed in more detail subsequently in this chapter. The main locations of the 65 tsunami linked to eruptions historically are plotted in Figure 7.2. The vast majority of these are restricted to the Japanese-Kuril Islands and the Philippine-Indonesian Archipelagos. Both of these regions form island arcs where one plate is being subducted beneath another. Explosive volcanism with caldera formation is a common occurrence in these regions. Other isolated cases of eruptions that have generated tsunami are associated with hot-spots beneath the Pacific Plate. Unfortunately, volcano-induced tsunami neither have been recorded well nor described except for a few events such as Krakatau in 1883.
KeywordsNatural Hazard Volcanic Eruption Common Occurrence Pacific Plate Death Toll
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