Can volcanic crystals predict eruptions?

Experts now believe that a chemical analysis of crystals encased in the magma within volcanic rocks can give a clearer picture of when eruptions will occur.

The magma crystals about 100 to 500 microns in diameter grow in concentric zones which make them look like tree rings.

Each zone has a distinct chemical makeup that can give scientists clues on internal volcanic activity.

Volcanologist Kate Saunders of the University of Bristol in England who led the study stated, "Crystals are a bit like a book: If you know your alphabet you can read the book. They provide a record for what happens."

“If we know what to look for and how to read them we can work out the processes that formed the magma and how long it took these processes to occur."

The chemical analysis revealed crystal formation starts building within 12 months of each eruption and peaks just before an explosion occurs.

Orthopyroxene crystal samples analyzed
To get an insight into volcanic activity with the aim to help predict it, researchers analyzed orthopyroxene crystal samples taken from nine different eruptions at Mount St.Helens in Washington from 1980 to 1986.

With the help of electron microscopy, the researchers examined to 98 crystals gathered over the course of eruptions and cross-checked the changes with records of volcano-related earthquakes that occurred during the same period.

The chemical analysis revealed crystal formation starts building within 12 months of each eruption and peaks just before an explosion occurs.

"Such a correlation between crystal growth and volcanic seismicity has been long anticipated, but to see such clear evidence of this relationship is remarkable," said Saunders.

Understanding volcanic activity
Though it is not possible to prevent earthquakes and volcanic activity, an accurate forecast and proper management of these hazards can minimize the damage that they cause. It can give people time to evacuate the area and make preparations for the event.

Experts concede the latest study cannot help scientists predict the time and day of an eruption. However, an understanding of the internal workings of a volcano can help experts anticipate their behavior and interpret future eruptions.

Saunders stated, “You wouldn't ask a doctor to predict the exact time of someone's death. However, by monitoring a patient's vital signs they are able to provide a much more thorough diagnosis."

"The same is also true with volcanoes. The more we know about the processes that occur beneath them and the timescales over which these occur, the better prepared we are to deal with future eruptions.”

The findings are detailed in the May 25 issue of the journal Science.