1:45 PM - 2:00 PM
[SVC34-07] Efforts to improve the Volcanic Alert Levels criteria
Keywords:volcanic alert levels, diagnostic criteria
The Japan Meteorological Agency has introduced the Volcanic Alert Levels into 48 volcanoes in Japan (as of February 1, 2022).
The Coordinating Committee for Prediction of Volcanic Eruption made recommendation just after the eruption disaster of Mt. Ontake. It was recommended that JMA should publish the criteria for determining the Volcanic Alert Level for each volcano in order to make climbers and local residents aware of when a warning will be announced, and conduct an in-depth review of the criteria in consideration of the possibility of a phreatic eruption such as that of Mt. Ontake. JMA has proceeded with the work based on the recommendations (Yamasato et al., 2016; Uhira et al., 2016) and almost completed it by March 2022.
Through the review process, we have examined the data observed in the historical volcanic unrests of each volcano in order to set the criteria that would ensure timely and prompt issuance of a warning in similar cases. However, there are only a limited number of suitable cases of historical volcanic unrests. As for volcanoes with little record of unrests, we referred to the criteria of those with more record in light of similarities in eruption histories and/or eruption styles. Although we have been striving to make the criteria as clear and understandable as possible, the limited observation data that can be referred to resulted in qualitative criteria in many cases.
Although we have been reviewing the criteria, we are still trying to improve them every time we experience actual volcanic unrests because the sequences of volcanic activity do not always proceed as expected. From April 2021 through March 2022, the criteria of the alert levels of Suwanosejima and Kuchinoerabujima were updated based on accumulated observation data of their intense activity.
In addition, after April 2022, we will refer to the latest volcanological research results in order to promote a better understanding of volcanic phenomena, and continuously aim to improve the criteria by quantification and multi-itemization.
The Coordinating Committee for Prediction of Volcanic Eruption made recommendation just after the eruption disaster of Mt. Ontake. It was recommended that JMA should publish the criteria for determining the Volcanic Alert Level for each volcano in order to make climbers and local residents aware of when a warning will be announced, and conduct an in-depth review of the criteria in consideration of the possibility of a phreatic eruption such as that of Mt. Ontake. JMA has proceeded with the work based on the recommendations (Yamasato et al., 2016; Uhira et al., 2016) and almost completed it by March 2022.
Through the review process, we have examined the data observed in the historical volcanic unrests of each volcano in order to set the criteria that would ensure timely and prompt issuance of a warning in similar cases. However, there are only a limited number of suitable cases of historical volcanic unrests. As for volcanoes with little record of unrests, we referred to the criteria of those with more record in light of similarities in eruption histories and/or eruption styles. Although we have been striving to make the criteria as clear and understandable as possible, the limited observation data that can be referred to resulted in qualitative criteria in many cases.
Although we have been reviewing the criteria, we are still trying to improve them every time we experience actual volcanic unrests because the sequences of volcanic activity do not always proceed as expected. From April 2021 through March 2022, the criteria of the alert levels of Suwanosejima and Kuchinoerabujima were updated based on accumulated observation data of their intense activity.
In addition, after April 2022, we will refer to the latest volcanological research results in order to promote a better understanding of volcanic phenomena, and continuously aim to improve the criteria by quantification and multi-itemization.