However, over the years, scientists realized that this ultrasimplified model did not match volcanic activity at Sakurajima.
To better forecast eruptions at Sakurajima, Hickey and his colleagues developed a much more complicated computer model -- one that incorporated the unique topography of the area surrounding the volcano. That model also took into account that the Earth's crust is made up of different layers, with different properties. Then, the team incorporated data from seismometers and highly precise GPS devices placed in and around the volcano. Those sensors revealed tiny changes in the Earth that were clues to the activity of the magma pool deep below.
RELATED: Undersea Volcanoes Could Affect Climate Change
The researchers discovered that the reservoir of magma beneath the caldera was growing at a significant rate. From this model, they forecast that it would take 130 years from the past major eruption for the next one to occur -- meaning the region is due for a major explosion around 2044.
The new model was better at capturing past behavior at the volcano, the researchers reported today (Sept. 13) in the journal Scientific Reports. It also found that the pool of magma beneath the caldera looks more squashed and oblong than spherical, Hickey said.
Volcanologists don't have a crystal ball, however, and the current forecast could be slightly off because they assume a constant growth rate for the magma pool. But if the daily eruptions were to increase to two or three times per day -- releasing small amounts of that magma -- that could offset the growth of the magma pool, which could delay a deadly eruption for a long time, Hickey said.
And even with highly accurate models, volcanoes sometimes surprise experts. For instance, in 2014, Mount Ontake volcano in Japan erupted without warning, killing about 57 people.
However, leaders in the region are already prepared for an eruption in the near term: The Kagoshima City Office prepared a new evacuation plan after an eruption scare in August 2015 prompted an evacuation crisis, study co-author Haruhisa Nakamichi, associate professor at the Disaster Prevention Research Institute, Kyoto University, said in a statement.
Original article on Live Science.
Copyright 2016 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Photos: Must-See Planet Pics