8 Février 2015
February 8, 2015
By TAKAYUKI KOZAKI/ Staff Writer
KAGOSHIMA--A volcano on an inhabited island in Kagoshima Prefecture that erupted last August for the first time in 34 years is again showing signs of increased volcanic activity.
The amount of volcanic gas emitted from Mount Shindake on Kuchinoerabujima island has increased greatly this year.
Experts said there was a possibility of volcanic activity, such as rising magma, and urged caution about a possible new eruption.
"There is the possibility that magma has reached close to the surface or its volume has increased," said Masato Iguchi, who heads the Sakurajima Volcano Research Center under Kyoto University's Disaster Prevention Research Institute.
When Mount Shindake erupted on Aug. 3, 2014, the first time since September 1980, volcanic fumes reached as high as 800 meters. A pyroclastic surge in which volcanic ash and hot gas flow quickly near the crater also occurred.
The Japan Meteorological Agency (JMA) raised the alert level from 1 to 3 on the scale of 1-5, meaning that restrictions are in place on approaching the 626-meter-high mountain.
About half of the approximately 140 residents on the island of about 36 square kilometers evacuated at that time. No injuries were reported, but 10 seismographs near the crater were damaged by falling volcanic rocks and cinder.
Normally after an eruption the volume of sulfur dioxide and other volcanic gas declines.
However, the volume being emitted from Mount Shindake has begun increasing from the start of 2015.
According to JMA officials, over the five-year period before the eruption, the daily volume of gas emitted was between 20 to 220 tons.
However, the daily volume increased to 500 tons in October 2014, 700 tons in November and as much as 1,900 tons in December. On Jan. 16, 2015, a volume of 3,100 tons was recorded. The volume was 2,700 tons on Feb. 1.
The mountain itself also shows signs of expanding.
The JMA's Fukuoka Regional Headquarters said there was a possibility of an eruption on a similar level as in last August occurring at any time.
It urged caution because volcanic rocks could be spewed over a radius of 2 kilometers from the crater and because there was also the possibility of a pyroclastic flow that could reach the ocean occurring in a southwest direction from the crater.
With no staff on the island to observe the volcano, experts have to rely on mechanical observations.
"Efforts should be made to construct a system of dispatching JMA workers to the island in order to detect an eruption as soon as possible and instruct residents to evacuate," Iguchi said.