Based on the fact that changes in tide levels were confirmed at domestic observation points in the eruption that occurred at the submarine volcano of Tonga in the South Pacific last month, the Japan Meteorological Agency will continue to issue "tsunami warnings" if an eruption of similar scale occurs overseas. We will use the framework of "" to disseminate information on changes in the tide level.
In the large-scale eruption that occurred at the submarine volcano of Tonga on the 15th of last month, the Japan Meteorological Agency once announced that "there may be some changes in the tide level, but there is no concern about damage", but since then, all over the country. Changes in the tide level from a few centimeters to a meter or so were observed, and tsunami warnings and warnings were announced over a wide area from Hokkaido to Okinawa.
Regarding a series of measures, the Japan Meteorological Agency was unable to promptly disseminate information on the observed tide level, and it took time to announce warnings, etc., and summarized the immediate measures.
Specifically, if a large-scale eruption with a height of 15,000 meters occurs overseas, there is a risk of a "tsunami" different from that associated with the earthquake, and it was observed overseas. In addition to notifying changes in the tide level, it is said that tsunami warnings and tsunami warnings will be announced promptly when the tide level reaches the standard in Japan.
In addition, the policy is to discuss the mechanism of changes in the tide level due to the eruption of Tonga and the way information should be disseminated with experts, and based on the discussion, we will improve the operation again.
Kazuki Miyaoka, Earthquake Information Planning Officer of the Japan Meteorological Agency, said, "If a similar phenomenon occurs, damage may occur. When a tsunami warning or warning is announced, we would like to ask you to evacuate according to the instructions of the local government."