Scientists from the University of California found out that volcanoes actually store magma in the coldest temperatures, going against the previously believed theory that magma is hot when stored in the volcano's deepest pits.

This was discovered after scientists analyzed the crystals found in lavas from Mount Hood, a volcano located at Oregon. The lava samples were from two different eruptions, one from about 1,500 years ago and the more recent one was about 220 years ago. The crystals were created deep within the volcano's chamber and a detailed analysis of them revealed a history of the volcano's internal temperature.

The crystals showed evidence that the magma from which they come from were stored in the coldest temperature for at most 100,000 years. The magma was so cold all the time that it formed crystals and was too heavy to escape out of the volcano. The scientists theorized that eruptions are caused by fresh magma coming out of the Earth's core, heating up the cold magma and pushing them out of the volcano.

"This tells us that the standard state of magma for this system is that it can't be erupted," geochemist from the University of California, Davis, Kari Cooper, said to LiveScience.com. "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."

For Mount Hood, the icy storage for magma is located about 2.5 to 3 miles below the surface. The temperature here can go as high as 1,380 degrees Fahrenheit as shown by the analysis of the crystal's structure. According to Kent and Cooper, the magma beneath Mount Hood may have been shifting from hot to cold all the time as fresh and hotter magma seeps from the lower levels of the volcano.

However, not all volcanoes behave the same way as Mount Hood does. Some volcanoes, like those found in Hawaii, are sitting atop of hot spots. On the other hand, scientists believe that there are more volcanoes which have the same setting as Mount Hood.

This study was published in the Feb. 16 issue of Nature.