Researchers believed they have cracked the code on how supervolcanoes produce their massive eruptions.

According to BBC News, previous studies have pointed to external triggers like an earthquake, but scientists believe it is much simpler and more frightening than that. Study lead author Wim Malfait, of ETH Zurich, said supervolcanoes can explode on their own with no provocation.

"Now we know you don't need any extra factor - a supervolcano can erupt due to its enormous size alone," he told BBC News. "Once you get enough melt, you can start an eruption just like that."

Malfait and his colleagues published their work Sunday in the journal Nature Geoscience. The team performed tests at the European Synchrotron Radiation Facility (ESRF) that suggested the high volume of magma was enough to set off a massive explosion. The team said such supervolcano eruptions can be predicted by examining their levels of magma, heat and pressure.

A supervolcano is only known to erupt every 100,000 years on average, making the event extremely rare. Today, there are about 20 known supervolcanoes and their explosions would have a devastating effect on the Earth's climate and ecology.

"This is something that, as a species, we will eventually have to deal with. It will happen in future," said Dr. Malfait. "You could compare it to an asteroid impact - the risk at any given time is small, but when it happens the consequences will be catastrophic."

For their tests, the researchers filled a diamond capsule with synthetic magma at the ESRF in Grenoble and then fired high-powered X-rays inside to influence high pressure causing critical mass conditions. "If we measure the density difference from solid to liquid magma we can calculate the pressure needed to provoke a spontaneous eruption," Mohamed Mezouar, an ESRF scientist, told BBC News. "To recreate the conditions in the Earth's crust is no trivial matter, but with the right vessel we can keep the liquid magma stable up to 1,700C and 36,000 atmospheres."

To illustrate his point that his team's study can predict a supervolcano eruption, Dr. Malfait used Yellowstone National Park as an example.

"The ground would probably rise hundreds of meters - a lot more than it does now," he said. "We think Yellowstone currently has 10-30 percent partial melt, and for the overpressure to be high enough to erupt would take about 50 percent."