5:15 PM - 7:15 PM
[SVC36-P10] Preliminary Research on Tsunami Hazard Assessment for Active Volcanoes in the Kuril Islands
Keywords:Volcanic topography, Sector collapse, Etorofu- Atosanupuri, Kharimkotan Island, Tsunamis in 1933
Introduction.
Since the tsunami from the 2018 Anak Krakatau eruption, research and countermeasures for tsunamis of volcanic origin have been advancing*1. The following month, a working group named Tsunamis Generated by Volcanoes (TGV) was established under UNESCO to strengthen measures against tsunamis of volcanic origin. Meanwhile, tsunamis have occurred in Japan as a result of eruptions and deformation of volcanic bodies, including the cases of Komagatake in Hokkaido in 1640, Oshima in 1741, and Bizan in Unzen in 1792, as well as the recent event in 2023 at Mt. While further strengthening of countermeasures is required, the Kuril Islands on the eastern margin of the Sea of Okhotsk are the region with the largest number of active volcanoes near the coast in Japan. However, tsunami hazard maps for Hokkaido (Hokkaido, 2023) and a study on expected tsunami wave heights in Primorsky Krai, Russia (Gusiakov et al., 2015) only consider seismic tsunamis and not events associated with volcanoes. Therefore, this study provides a tentative hazard assessment of tsunamis associated with volcanic body collapse at onshore volcanoes in the Kuril Islands. Pyroclastic eruptions, atmospheric changes caused by eruptions, and submarine volcanic eruptions are not included in this study.
Hazard Assessment
Zone et al. (2022) identified 19 volcanoes located within 20 km of the coast in Southeast Asia that are at high risk of tsunami generation by scoring the ratio of the distance from the mountain to the coast to the elevation of the mountain (H/D ratio), frequency of eruptions, and presence of a history of tsunami generation. Although the results are semi-quantitative, they are sufficiently useful to indicate the need for the introduction of a monitoring system for volcano-derived tsunamis, disaster prevention education, and international cooperation.
Therefore, in this study, with reference to the criteria of Zone et al.
We selected 19 volcanoes based on Google Earth and Sentinel-2 imagery and topographic data, using the height and distance to the coast (H/D ratio) as the main criterion (Table 1).
Among these volcanoes, Harumukotan-jima and Arayudo-jima were confirmed to have generated tsunamis in 1933 (Miyatake, 1934; Tanaka, 1934), suggesting a real threat of volcanic origin of tsunami generation in the Kuril Islands. If the average H/D ratio of the volcanoes selected by Zone et al. (0.6) is used as a criterion, and volcanoes exceeding this value are considered to be relatively high-risk volcanoes, seven of them would fall into this category: Mt. Mt. In particular, Mt. Etorofu-Atosa is a volcano that should be the focus of immediate attention due to its proximity to the Hokkaido coast. On the other hand, no volcanoes were selected from the large southern islands of Shiretoko Peninsula, Kunashiri Island, and Tokunashi Island. On the day of the presentation, we will report the results of our study, including the results of other evaluation factors.
Since the tsunami from the 2018 Anak Krakatau eruption, research and countermeasures for tsunamis of volcanic origin have been advancing*1. The following month, a working group named Tsunamis Generated by Volcanoes (TGV) was established under UNESCO to strengthen measures against tsunamis of volcanic origin. Meanwhile, tsunamis have occurred in Japan as a result of eruptions and deformation of volcanic bodies, including the cases of Komagatake in Hokkaido in 1640, Oshima in 1741, and Bizan in Unzen in 1792, as well as the recent event in 2023 at Mt. While further strengthening of countermeasures is required, the Kuril Islands on the eastern margin of the Sea of Okhotsk are the region with the largest number of active volcanoes near the coast in Japan. However, tsunami hazard maps for Hokkaido (Hokkaido, 2023) and a study on expected tsunami wave heights in Primorsky Krai, Russia (Gusiakov et al., 2015) only consider seismic tsunamis and not events associated with volcanoes. Therefore, this study provides a tentative hazard assessment of tsunamis associated with volcanic body collapse at onshore volcanoes in the Kuril Islands. Pyroclastic eruptions, atmospheric changes caused by eruptions, and submarine volcanic eruptions are not included in this study.
Hazard Assessment
Zone et al. (2022) identified 19 volcanoes located within 20 km of the coast in Southeast Asia that are at high risk of tsunami generation by scoring the ratio of the distance from the mountain to the coast to the elevation of the mountain (H/D ratio), frequency of eruptions, and presence of a history of tsunami generation. Although the results are semi-quantitative, they are sufficiently useful to indicate the need for the introduction of a monitoring system for volcano-derived tsunamis, disaster prevention education, and international cooperation.
Therefore, in this study, with reference to the criteria of Zone et al.
We selected 19 volcanoes based on Google Earth and Sentinel-2 imagery and topographic data, using the height and distance to the coast (H/D ratio) as the main criterion (Table 1).
Among these volcanoes, Harumukotan-jima and Arayudo-jima were confirmed to have generated tsunamis in 1933 (Miyatake, 1934; Tanaka, 1934), suggesting a real threat of volcanic origin of tsunami generation in the Kuril Islands. If the average H/D ratio of the volcanoes selected by Zone et al. (0.6) is used as a criterion, and volcanoes exceeding this value are considered to be relatively high-risk volcanoes, seven of them would fall into this category: Mt. Mt. In particular, Mt. Etorofu-Atosa is a volcano that should be the focus of immediate attention due to its proximity to the Hokkaido coast. On the other hand, no volcanoes were selected from the large southern islands of Shiretoko Peninsula, Kunashiri Island, and Tokunashi Island. On the day of the presentation, we will report the results of our study, including the results of other evaluation factors.