Japanese volcanologist monitoring the volcano warned that a larger eruption could occur in the near future. The alert level of the volcano was raised to the second highest, 4 out of 5, meaning that of nearby areas (within a few km from the Showa crater) are in progress.
The alert was based on a strong swarm of shallow volcanic earthquakes located beneath the Showa crater. The seismic swarm started around 7 am on 15 Aug (local time), and peaked with almost 180 quakes per hour around noon. It gradually waned, but continues with weaker intensity until now.
At the same time, a significant inflation of the Showa crater has been detected. These both are likely caused by the rising of a new batch of magma, which could result in a larger-then-usual eruption.
Yesterday, the tectonic movements indicating the inflation of the mountain have slowed, the Meteorological Agency said. They believe that the rise of magma from a subterranean chamber decreased yet. But Takeshi Koizumi, Senior Coordinator for mitigating volcanic disasters at the agency, said: « We must remain vigilant because it is not known when the magma will start to rise again and when a major eruption will occur as a result. « The government of the city of Kagoshima issued an evacuation notice for areas near the mountain, affecting 77 residents, all of whom left the area at night.
The agency warned of the possibility of an eruption emits large amounts of ash and pyroclastic within 3 km of the Sakurajima Showa vent and Minamidake summit. According to the agency, there is a large magma chamber at a level of about 10-15 km below the surface of the sea northeast of Sakurajima, and it is thought that the magma in this room is pushed into a second small magmatic chamber at 4 or 6 km directly below the mountain. The agency says that the increased pressure in the small chamber has likely led to increase the frequency of volcanic earthquakes and cause swelling of the mountains.
August 17, 2015. Sakurajima , Kyushu, Japon :
Source : T Pfeiffer, Japan times .
Photo : Kyodo.