JDR Vol.19 No.1 pp. 50-55
doi: 10.20965/jdr.2024.p0050

Survey Report:

Vulnerability of Aso Volcano’s Disaster Mitigation System, as Revealed by the Phreatic Eruption of October 20, 2021

Takahiro Ohkura ORCID Icon

Aso Volcanological Laboratory, Institute for Geothermal Sciences, Graduate School of Science, Kyoto University
5280 Kawayo, Minamiaso, Aso, Kumamoto 869-1404, Japan

Corresponding author

August 21, 2023
December 15, 2023
February 1, 2024
disaster prevention literacy, phreatic eruption, Aso volcano, transmission of volcano information to climbers, improving volcanic disaster prevention literacy of climbers

At Aso volcano, phreatic and phreatomagmatic eruptions have repeatedly caused volcanic disasters with fatalities near the crater. While it is important to conduct research on eruption forecasting for reducing the risk to tourists and climbers of this volcano, it is also important to improve disaster prevention literacy regarding the volcanic eruptions. To improve disaster prevention literacy, it is important to elucidate the mechanisms of volcanic disasters based on case studies. In this study, the author chronologically summarizes the incident of the phreatic eruption that occurred in 2021 at Aso volcano. Although the Japan Meteorological Agency issued volcanic activity information sequentially as the volcanic activity increased, this information did not lead to prompt and effective closure of mountain trails. There was also a problem with the collection of volcanic information by climbers. It became clear that information on volcanic activity was not used effectively by either those regulating the mountain trails or those using them. Efforts should be made to resolve these issues in the future.

Cite this article as:
T. Ohkura, “Vulnerability of Aso Volcano’s Disaster Mitigation System, as Revealed by the Phreatic Eruption of October 20, 2021,” J. Disaster Res., Vol.19 No.1, pp. 50-55, 2024.
Data files:
  1. [1] Y. Miyabuchi, Y. Iizuka, C. Hara, A. Yokoo, and T. Ohkura, “The September 14, 2015 phreatomagmatic eruption of Nakadake first crater, Aso Volcano, Japan: Eruption sequence inferred from ballistic, pyroclastic density current and fallout deposits,” J. Volcanol. Geotherm. Res., Vol.351, pp. 41-56, 2018.
  2. [2] A. Terada et al., “The 2018 phreatic eruption at Mt. Motoshirane of Kusatsu–Shirane volcano, Japan: Eruption and intrusion of hydrothermal fluid observed by a borehole tiltmeter network,” Earth Planets Space, Vol.73, No.1, 157, 2021.
  3. [3] D. Sasaki, Y. Jibiki, and T. Ohkura, “Tourists’ behavior for volcanic disaster risk reduction: A case study of Mount Aso in Japan,” Int. J. Disaster Risk Reduct., Vol.78, 103142, 2022.
  4. [4] Japan Meteorological Agency (JMA), “National Catalogue of the Active Volcanoes in Japan (The 4th Edition),” 2013. [Accessed August 18, 2023]
  5. [5] H. Kawakatsu et al., “Aso94: Aso seismic observation with broadband instruments,” J. Volcanol. Geotherm. Res., Vol.101, Nos.1-2, pp. 129-154, 2000.
  6. [6] K. Fukada, “One Hundred Famous Mountains of Japan,” Shinchosha Publishing Co., Ltd., 1991 (in Japanese).
  7. [7] National Institute of Advanced Industrial Science and Technology, “Catalog of eruptive events during the last 10,000 years in Japan, version 2.5” (in Japanese). [Accessed August 17, 2023]
  8. [8] H. Yamasato, “Volcano monitoring and information for the society,” Bull. Volcanol. Soc. Jpn., Vol.48, No.1, pp. 115-119, 2003 (in Japanese).
  9. [9] H. Yamasato, “Modern history of volcano observation in Japan: Especially volcano surveillance of Japan Meteorological Agency,” Bull. Volcanol. Soc. Jpn., Vol.50, Special Issue, pp. S7-S18, 2005 (in Japanese with English abstract).
  10. [10] A. Kubotera, “ Mechanism and Prediction of Volcanic Eruptions,” Kokon Shoin, 1991 (in Japanese).
  11. [11] Fukuoka Regional Headquarters, JMA (In Japanese). [Accessed August 17, 2023]
  12. [12] N. Sekiya, “Disaster Information and Social Psychology: Lessons from the Great East Japan Earthquake,” University of Tokyo Press, 2021 (in Japanese).

*This site is desgined based on HTML5 and CSS3 for modern browsers, e.g. Chrome, Firefox, Safari, Edge, Opera.

Last updated on Feb. 19, 2024