According to new research, the crystals that form in the molten rock of a volcano may hold important clues and help predict the next eruption of Mount St. Helens or Mount Vesuvius by as much as a year in advance.
Scientists analyzed data from the explosions of Mount St. Helens from 1980 through 1986 in Washington, and found that crystals rich in iron and magnesium formed before an eruption, details the study in the journal Science. The data showed that the most rapid growth occurred in the 12 months before the volcano erupted.
According to the U.S. Geological Survey, volcanoes often erupt with very little clear warning beforehand, and efforts to predict eruptions consist of monitoring seismic activity, ground deformations, gas emissions, as well as changes in water levels and chemistry. With the newest findings, scientists may be able to better assess the signs and give advance warning of a potential eruption.
"Volcanoes tend to erupt in a similar cycle and have similar trends," Kate Saunders, study author and geologist at the University of Bristol in England, told Bloomberg BusinessWeek in a phone interview. "If we can work out their behavior, it allows us to know what to look for. We can better evaluate the monitoring signals." For now, however, Saunders and colleagues "have no predictions on what might erupt soon."
According to the U.S. Geological Service (USGS), 29,000 people worldwide were killed by volcanic eruptions since 1980. There are 169 active volcanoes in the United States, mainly in Alaska, and roughly 1,500 worldwide. Of the active volcanoes in the U.S., 54 are considered a high or very high threat, according to the USGS.
A volcano eruption is a serious threat not only to people on the ground, but to air travel as well. In 1989, for instance, KLM Flight 867 carrying 240 passengers aboard was hit by an ash cloud from the eruption of Mt. Redoubt near Anchorage, Alaska, causing the plane's engines to fail. The crew managed to land the plane safely, but the aircraft suffered $80 million worth of damage.
Mount St. Helens erupted on May 18, 1980, following months of smaller explosions and earthquakes. The eruption killed 57 people, including David Johnston, the geologist who first radioed warning of the eruption from an observation point. According to the USGS, thousands of lives were saved due to Johnston's insistence that people be denied access to the area that year.
The paper published in the journal Science shows that during the 12 months before the eruptions, iron- and magnesium-rich crystals grew more quickly. Moreover, data show the growth of these crystals coincided with increased earthquake activity and increased data emissions. That may indicate that new magma pulsed into the inner chamber of the volcano. With this information, scientists may better understand the hidden life of a volcano and its inner mechanisms.
Saunders plans to focus her future research on linking crystal composition to other monitoring methods, allowing for an even better understanding of volcanoes. According to Saunders, these crystals are like a book that gives scientists a record of the activity within the volcano. "If you know the alphabet, you can read the book," she said. "And the better we understand a volcano, the better we can predict eruptions."
