According to a new research, prediction of volcanic eruptions can be easier when the magma cools down. This was discovered from the study of crystals, collected from two volcanic eruptions of Mount Hood, which occurred 1,500 and 200 years ago - stored for about 100,000 years below the volcano. Crystals created during each volcanic eruption, provided clue to the history behind the eruptions, including temperatures.

From this method, scientists determined - based on the average recorded temperature of magma -1,380 degrees Fahrenheit is not enough to trigger a volcanic eruption. According to researchers, if the magma's temperature increased by 200 degrees Fahrenheit, it could initiate another eruption.

"This tells us that the standard state of magma for this system is that it can't be erupted. That means that having a magma that can erupt is a special condition. Our expectation is that there's a lot of volcanoes that behave this way," Live Science quoted Kari Cooper, professor of geology at the University of California.

Mount Hood was formed by a subduction zone - a situation when a continental plate hits the second one below. As this crust is pushed to the ground, it heats up the rocks and melts it, leading to volcanic eruption.

Researchers believe that monitoring the movement of the magma can be useful in predicting the eruptions as well as the temperatures within the crust for most type of volcanoes.

"If you can see a body of magma that has a high amount of liquid, perhaps this magma is getting ready to erupt or at least has some potential to erupt. It wouldn't be a slam-dunk guarantee," Adam Kent, co-author of the study and professor of Geology at Oregon State University, added. 

Researchers explain that when crystals make up over 50 percent of the magma, it becomes too solid to leak from earth's cracks. This prevents eruptions from occuring. With the use of seismic waves, scientist can possibly detect when the magma beneath the Mount Hood is liquid, which in turn can help in identifying a possible erupt.

The finding have been published in the Science Journal.