Mount Fuji eruption to wreak havoc on Japan

Mount Fuji, Japan’s highest peak, has seen growing volcanic activity. Volcanologists warn that the mountain, which has remained idle over the past 300 years, could cause a massive catastrophe with an eruption.

According to the water control authority of Japan`s Yamanashi Prefecture, the water level of Kawaguchi Lake, located 5 kilometers from the mountain, rapidly fell to 7.4 meters March 4, below its reference point of 3.2 meters. Part of the lake`s bottom is now visible.

“The water level of a lake is highly sensitive to changes underground. We can’t entirely exclude the possibility of an eruption of Mount Fuji,” said Hideki Shimamura, a geology professor at Musashino Gakuin University, in a news interview.

Earthquakes caused by volcanic activity have also increased. Fuji Television reported that Hakone, one of Japan’s most popular hot spring resort areas and located about 30 kilometers from Mount Fuji, has experienced 1,700 micro seismic tremors this year, or 10 times of that of last year. Such tremors occurred up to 150 times a day, leading to a temporary suspension of tourist cable car.

Mount Fuji has not erupted since its last eruption in 1707. But another eruption has been predicted from decades ago. A Japanese institute for predicting volcanic eruptions reviewed a "scenario about an eruption of Mount Fuji" for the first time in February 2001.

According to the Japanese Central Disaster Prevention Council, if an eruption occurs with the same volume of volcanic ejecta with a diameter of 0.7 cubic kilometers as the mount`s eruption in 1707, the economic losses could reach 2.5 trillion yen (32 billion U.S. dollars).

Most of the damage would come from the volcanic ash. Ash up to half a millimeter makes it impossible to harvest rice while that of 5 millimeters forces road closures. Power outages, radio interference and paralysis of water and sewage systems occur if the ash rises to 1 centimeter. Tokyo, which is about 100 kilometers from the mountain, would be covered with volcanic ash of 2 to 10 centimeters, meaning the function of the country’s capital would be practically paralyzed.

With the heightened alarm over a volcanic eruption, the prefectures of Yamanashi, Shizuoka and Kanagawa, all of which are near Mount Fuji, have begun discussing responses. They set up a disaster countermeasure council in June last year, and on March 22 this year, the council recommended that about 750,000 people need to evacuate their homes if the mountain erupts. Another recommendation is that each prefecture designate buildings for evacuation in the event of an eruption just like those designated in preparation for a tsunami.

Fortunately, Mount Fuji is not likely to erupt in the near future. Before a volcanic mountain erupts, the temperature of its magma rises and causes significant changes in crustal movement, which have not been detected around the mountain.

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