Japanese Volcano Could|Blow Within 30 Years


     (CN) — A major eruption of one of Japan’s most active volcanoes could happen in the next 30 years, a growing threat to a nearby city of 600,000.
     The Sakurajima volcano, which killed 58 people and caused widespread flooding in Kagoshima after an explosive eruption in 1914, has small eruptions almost daily which are not large enough to pose any significant danger.
     However, scientists have found that another large eruption could occur within the next three decades.
          “It is already passed by 100 years since the 1914 eruption, less than 30 years is left until a next expected big eruption, Kagoshima city office has prepared new evacuation plans from Sakurajima, after experiences of evacuation of the crisis in August 2015,” study co-author Haruhisa Nakamichi said.
     The team analyzed magma buildup around the volcano and the Aira caldera, which was created after a violent explosion and subsequent collapse of a massive magma reservoir. They found that this magma storage zone has been feeding Sakurajima volcano, likely increasing the size of its next eruption.
     The researchers studied surface deformations in and around the caldera and volcano to characterize the magma build-up, and determined how such information could be used for eruption forecasting and hazard assessment.
     Their results show that magma is being supplied to the system at a faster rate than it is being erupted from the Sakurajima volcano. The volume of magma supplied to the system each year could fill an area 3.5 times the size of London’s Wembley Stadium, which seats 90,000 people.
     The findings were published Tuesday in the journal Scientific Reports.
     The buildup of magma might indicate a growing potential for a larger eruption, which would take roughly 130 years of magma stockpiling since the deadly 1914 eruption, according to the team.
     “A thorough understanding of the rate and volume of magma supply and accumulation, and their thermomechanical controls, is essential for continued monitoring and eruption forecasting at Sakurajima volcano, and volcanoes worldwide,” study co-author Joachim Gottsmann said.
     
     Top photo: S. Fujioka

%d bloggers like this: