Japan Geoscience Union Meeting 2023

Presentation information

[J] Oral

H (Human Geosciences ) » H-DS Disaster geosciences

[H-DS06] Tsunami and tsunami forecast

Tue. May 23, 2023 9:00 AM - 10:15 AM 106 (International Conference Hall, Makuhari Messe)

convener:Satoko Murotani(National Museum of Nature and Science), Toshitaka Baba(Graduate School of Science and Technology, Tokushima University), Chairperson:Kei Ioki(National Institute of Advanced Industrial Science and Technology), Takuto Minami(Division of Frontier Planetology, Department of Planetology, Graduate School of Science, Kobe University)

9:15 AM - 9:30 AM

[HDS06-07] Information on tide level changes due to volcanic eruptions -Operation of the Japan Meteorological Agency-

*Kazuyuki Hirano1, Shota Imamura1, Miwa Kuri1, Tatsuo Kuwayama1, Ayataka Ebita1 (1.Japan Meteorological Agency)

Keywords:tide level change, tsunami information

Due to the large-scale eruption of Hunga Tonga-Hunga Ha'apai volcano in January 2022, changes in atmospheric pressure and significant changes in tide levels were observed along the coast of Japan. Based on the knowledge obtained at the "Study Group on Tsunami Forecasting Technology" that examined the mechanism of tsunami occurrence, In order to minimize the damage caused by tidal changes in the event that similar phenomena occur in the future, it is necessary to issue information that will contribute to disaster mitigation correspondence by residents and local governments, etc. we asked the "Study Group on Information on Tide Changes Due to Volcanic Eruptions, etc." to consider how this information should be. In this presentation, we will report on the results of the review by the study group, the operation of information dissemination by the Japan Meteorological Agency based on the results of the review, and future medium- to long-term issues.

(Results of the review by the study group)
・Utilize the tsunami warning/advisory system based on the observation results of tide level and atmospheric pressure to call for caution.
・Provide information as a “tsunami” in disaster mitigation correspondence.
・On tide level changes caused by atmospheric pressure waves caused by volcanic eruptions, provide detailed explanations and information using time until tidal change reaches Japan.
・In addition to atmospheric pressure waves, volcanic phenomena such as volcanic collapse may also cause tide level changes, and tsunami warnings and advisories are issued based on observation results.
・Even if the phenomenon is rare, it is important to spread awareness during normal times and provide detailed explanations at press conferences, etc. when the phenomenon occurs in order to connect it to disaster mitigation correspondence.
・Categorize information announcement scenarios and disaster mitigation considerations for tide level changes caused by volcanic phenomena and earthquakes by dividing them into "long and short lead times" and "presence or absence of tremors."

(Operation of information dissemination by the Japan Meteorological Agency)
・In the event of a large-scale eruption overseas, we will inform you that there is a possibility that changes in tide level will be observed in Japan as well.
・Notify the time when the tide level change is expected to reach the earliest along the coast of Japan
・Provide observation results of tide level changes at tide stations in Japan and overseas, atmospheric pressure changes in Japan, analysis results of meteorological satellite Himawari images, and estimated time for the next information release.
・In response to subsequent changes in tide levels in Japan, tsunami warnings and advisories will be issued using procedure such as tsunami warnings.
・When observation results closely related to the occurrence of tsunamis are obtained, provide detailed explanations and information at press conferences, etc.

(Future medium- to long-term issues)
・Changed the name of "Information on distant earthquakes"
・Extraction of eruptions with possible tidal changes
・Technical development and consideration of utilization of offshore tsunami observation points, etc.