[M-IS23] Fusion of volcanology and meteorology

[MIS23-P03] The influence of wind and ejection anlgle on the transport of ballistic projectiles during the July 24, 2022 eruption at Sakurajima Volcano

*Kae Tsunematsu¹ (1.Yamagata University)

Keywords:Sakurajima Volcano, July 24, 2022, Ballistic projectile, wind

An explosive eruption, which caused ballistic projectiles to travel more than 2.4 km from the vent, occurred at Sakurajima Volcano on July 24, 2022. As the JMA estimated that the travel distance of the ballistic projectile was around 2.5 km, they raised the alert level of volcanic activity at Sakurajima Volcano to level 5. However, it was reported that the acoustic data record of this explosion was not so large. Therefore, it is necessary to validate whether the travel distance was really larger than 2.5 km. We analyzed images from the monitoring camera installed at the Kaigata station which is southeast of the Sakurajima volcano. Based on the image analysis, we estimated the travel distance of ballistic projectiles which was less than2.5 km. Moreover, the ejection angle was tilted to south-southeast. According to the wind data of JMA, the wind direction was from southeast to northwest. Therefore, the projectile distribution was affected by the ejection angle and not by the wind direction.