Updated: 2/16/2018 1:24:08 AM
Researchers at Kobe University have detected the lava dome holds almost eight cubic miles of trapped magma.
This build-up of often rock has sparked concerns Kikai is silently building up towards a roaring super-eruption.
An eruption of this scale would endanger as many as 100 million people, the researchers have gravely concluded.
Volcanologist Yoshiyuki Tatsumi said: "The most serious problem that we are worrying about is not an eruption of this lava dome, but the occurrence of the next super-eruption.”
But according to Mr Tastumi’s research there is only about a one percent chance of a “catastrophic” caldera disaster within the next 100 years.
Kikai last erupted around 7,300 years ago and is believed to be the culprit behind the extinction of the Japanese Jomon civilisation.
Published Wednesday, January 24, 2018
A sudden eruption took place at Kusatsu-Shirane volcano (Kusatsu-Shiranesan) in Japan early Tuesday, January 23, 2018, causing an avalanche that left one member of Japan's Self-Defense Forces (SDF) dead and 6 injured. At least 11 people were injured by falling volcanic rocks. It was the first eruption of this volcano since 1983.
The volcano, located near a ski resort in Gunma prefecture, erupted at 01:59 UTC on Tuesday (09:59 local time), spawning an avalanche that buried 6 soldiers and killed one, officials said. All 7 were transported to a hospital where one was later confirmed dead. SDF said at the time that the soldiers were training in the area when the volcano erupted and that they are trying to rescue about 80 people who were visiting the ski resort and evacuated to a ropeway station at the peak.
Falling volcanic rocks injured 11 people, local police said. At least 5 of them were injured after the stones hit a gondola lift, shattering its windows. The injured were treated at a rest house.
Observations by the Tokyo Institute of Technology have confirmed volcanic rocks about 1 km from the crater near Kagamiike pond, on Motoshirane peak. Some of the stones appeared to be 10 - 20 cm in size.
According to the Tokyo Electric Power Company, a power outage occurred near the ski resort after the eruption.
The Japan Meteorological Agency raised the volcanic alert level to 3, warning people not to approach the volcano. A large amount of ash is present in the area, the agency added, urging elderly, children and others in need of aid during evacuations to begin preparations to leave the area.
JMA said it did not observe any data showing heightened volcanic activity prior to the eruption.