To accurately predict volcanic eruptions, volcanologists often conduct extensive research on the volcano's eruptive history and continuously monitor data coming from their equipment.
Now, a new discovery might help scientists gain a better understanding of what happens inside magma chambers and how these buildups lead to volcanic eruptions. This landmark finding may help experts determine when a volcano threatens the most danger, experts say.
Predicting Volcanic Eruptions
In a report published in the journal Science, a team of researchers collected volcanic crystals called zircon crystals from debris deposited around New Zealand's Mount Tarawera. Studying magma directly is difficult, but from these zircon crystals, the group can safely investigate the eruptive history of the volcano.
When Mount Tarawera erupted 700 years ago, it released lava about five times the amount of that of the Mount St. Helens eruption in 1980. Once on the surface, the lava's chemistry and temperature both got frozen in place.
Geoscientist Kari Cooper said examining zircon crystals to investigate the volcano's magma is efficient because these crystals act as a "black box" flight recorder.
"[T]he crystals can tell us what was going on while they were below the surface, including the run-up to an eruption," said Cooper.
How Volcanic Crystals Formed In Mount Tarawera
Researchers traced elements in seven of these volcanic crystals they acquired to determine when these crystals formed and how long they had been exposed to high heat. They found that the zircon crystals were created tens of thousands of years ago as magma cooled down and that these crystals only spent 4 percent of that time exposed to molten magma.
What Cooper and her colleagues discovered is not a seething mass of molten rock but solid and crystalline magma with little liquid seeping through it. They conclude that for an eruption to take place, solid crystalline magma must melt and become active by potentially interacting with hotter liquid in the magma reservoir.
This solid crystalline magma possibly draws its material from various parts of the reservoir, scientists said. This process likely takes place from decades to centuries, which means volcanologists can identify which volcanoes are at the highest risk of eruption just by examining those with the most mobile magma.
Geoscientist Christy Till, coauthor of the new study, believes their findings will have a significant impact on volcanology.
"Our idea of how the magma reservoir below a volcano behaves has evolved a lot over the last 10 or 15 years," said Till.
Meanwhile, as scientists track the cooling of magma into solid crystals, they have yet to understand what exactly triggers a volcano to erupt. It's a process they simply don't understand yet, added Till.