Scientist warns of Fuji eruption chaos

Snow covers the peak of Japan's Mount Fuji, with the city of Gotenba below

Scientist warns of Fuji eruption chaos – ABC News (Australian Broadcasting Corporation).

Pressure under Japan’s Mt. Fuji volcano rising: eruption would be nightmare for Japan

September 7, 2012 – JAPAN - Pressure in the magma chamber of Japan’s Mount Fuji is now higher than it was the last time the volcano erupted more than 300 years ago, scientists say, according to a report Thursday. Tectonic shifts triggered by last year’s huge 9.0 magnitude undersea quake have left the chamber under 16 times the minimum pressure at which an eruption can occur, researchers said. Researchers at the National Research Institute for Earth Science and Disaster Prevention studied the tectonic movements caused by the tsunami-triggering quake on March 11, 2011 and a magnitude 6.4 quake that rocked central Japan four days later, Kyodo News reported. They estimated that 1.6 megapascals of pressure, equivalent to atmospheric pressure of some 15.8 kilograms per square centimeter (226 pounds per square inch), was being exerted on the magma chamber. Volcanic eruptions can be triggered by as little as 0.1 megapascals of pressure, and the reading of 1.6 megapascals is “not a small figure,” said senior researcher Eisuke Fujita, according to Kyodo. Mount Fuji, an almost perfectly cone-shaped mountain that stands as one of Japan’s national symbols, last erupted in 1707, after an earthquake struck and boosted the pressure on its magma chamber, the report said, citing researchers. Scientists say an eruption some time over the coming years is a possibility, but add that heightened pressure is not the only variable. They say so far no signs of activity have been seen at Mount Fuji, possibly because the amount of magma that has accumulated is not substantial enough, Kyodo said. If Mount Fuji erupts, it could cause up to 2.5 trillion yen ($32 billion) of damage, according to a government report in 2004, Kyodo said. In May a team of researchers warned that the mountain may collapse if a newly-discovered fault line underneath it shifts. The huge quake of March 2011 and tsunami that it generated devastated a large area of the country’s northeast, killing around 19,000 people and generating a nuclear emergency at Fukushima. –Physics

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Japan’s Sakurajima volcano releasing largest amount of ash in 20 years: ground swollen around volcano

August 17, 2012 – JAPAN - Sakurajima Volcano has been steadily erupting for some time now. So much so that residents were asked to cover up and wear masks as a health and safety measure. According to researchers, this active volcano in Kagoshima Prefecture could release its largest amount of ash in two decades this year alone. Going by the current stats available, the mountain has already spewed enough ash from January to July, amounting to twice the amount emitted in all of last year. Masato Iguchi, a professor at the Sakurajima Volcano Research Center said that last year saw a record number of eruptions as well. The ground around Sakurajima indicates the buildup of magma and appears swollen. And if Sakurajima keeps being as active it is right now, we can expect the amount of ash expelled to be a new record. In the past two decades this year’s activity of explosions and ash fall have both risen dramatically. As a part of the Kyoto University’s disaster reduction research institute, keeping a tab on such stats is imperative to avoid another Pompeii. You may recollect the 1914 eruption as one of the deadliest one that killed 58 people. Presently, Minamidake crater erupted last month for the first time in about a year and a half and the Showa crater has been active since 2008. –Japan Daily Press

Kirishima volcano in Kyushu, Japan on high alert level

July 30, 2012 – JAPAN – As our colleague Marc Szlegat reported on Vulkane.Net, the alert level of the Japanese Kirishima volcano (Kirishimayama) was raised last month “orange.” This is the third out of 4 warning levels and means that an eruption could occur any time. Last year in March, the Shinmoedake crater of the complex volcano Kirishima had a violent eruption that make the headlines. The volcano is located close to the other volcano currently on orange alert in Kyushu, Sakura-jima, which last week had a stronger explosion that caused ashfall in the nearby city of Kagoshima. –Volcano Discovery

Japan’s Sakurajima volcano marks 600th eruption this year with massive explosion

Posted on July 25, 2012
July 25, 2012 – JAPAN - The Sakurajima volcano in southern Japan has erupted, spewing volcanic ash onto Kagoshima City. The eruption at one of Japan’s most active volcanoes showered ash on the streets of Kagoshima, which lies just 2km across a bay from the volcano. Residents of Kagoshima donned face masks to protect themselves while sweeping away the ash. The volcano has erupted more than 600 times this year and is expected to continue its intermittent eruptions. Currently, the volcano warning there is at level three out of a possible five levels. A level five would mean that the residents living near the crater would have to be evacuated, while level three warns people not to approach the volcano. –Herald Sun