Regarding "Mt. Aso," which raised the eruption alert level last month because of active volcanic activity, the Japan Meteorological Agency said, "Although the amplitude of volcanic tremors has subsided, there are movements that indicate expansion of the mountain body just below the crater. We are calling for caution within a range of approximately 2 km from the crater.
Regarding "Mt. Ontake," he said, "Although the temporary increase in activity has subsided, it has not returned to its previous state, and caution is still required."
The Japan Meteorological Agency announced last month the activity status of active volcanoes nationwide and points to watch out for.
As a result, the amplitude of volcanic tremors increased on the 24th of last month at Mt. Aso in Kumamoto Prefecture, so the eruption alert level was raised from "2" to "level 3", which indicates entry restrictions.
Although the amplitude of the tremor has subsided after repeated increases and decreases, the amount of volcanic gas released has been high since the eruption last fall.
For this reason, the Japan Meteorological Agency is calling for caution against large volcanic bombs and pyroclastic flows that scatter within a range of approximately 2 km from the crater.
In addition, the eruption alert level was raised to "2" because volcanic earthquakes increased on the 23rd of last month and crustal movements uplifted on the south side of the mountaintop were observed on Mt. Ontake on the prefectural border between Nagano and Gifu.
Since then, the number of earthquakes has decreased, and although no other noticeable changes have been confirmed in other observational data, large volcanic bombs are being warned within a range of approximately 1 km from the crater.
At Shinmoedake in the Kirishima mountain range on the prefectural border between Kagoshima and Miyazaki, volcanic earthquakes increased earlier this month, and crustal movements indicating the accumulation of magma deep underground were observed.
Since then, activities such as volcanic earthquakes have subsided.
Sakurajima in Kagoshima Prefecture had two eruptions last month, and since November last year, gradual crustal movements indicating mountain expansion have been observed intermittently. It is said that it may become more active.
Suwanosejima in the same Kagoshima prefecture has few volcanic bombs scattered from the crater last month, but active eruptive activity continues, such as a temporary increase in explosions.
Masamichi Nakamura, Volcanic Activity Evaluation Analyst, Volcanic Monitoring Division, Japan Meteorological Agency, said, "At Mt. Although the number of volcanic earthquakes on Mt. I did.