NASHVILLE, July 21 (UPI) -- If planetary doom is to arrive by supervolcano, Earthlings will have about a year to consider their options. According to new research, super-eruptions offer a warning approximately one year before they blow up.
Super-eruptions are eruptions of supervolcanos -- eruptions capable of ejecting magma, debris and soot across vast regions and triggering global climate change.
There have been a number of super-eruptions throughout Earth's history. Recently, scientists at Vanderbilt University analyzed quartz crystals in pumice collected from supervolcano sites.
Super-eruptions are years in the making. First, magma from the mantle rises, collects and pushes up against the crust. As it accumulates but is unable to break through, pressure builds. This process occurs on a large timescale, but researchers have identified a predictive process occurring on a smaller timescale -- rim growth.
Researchers were able to use the amount of titanium accumulated in quartz crystals to measure a volcano's rim growth over time. Maximum rim growth corresponds with decompression, the release of pressurized gas that powers a super-eruption -- the beginning of the end.
"Maximum rim growth times span from approximately 1 minute to 35 years, with a median of approximately 4 days," researchers wrote in their new paper on the subject. "More than 70 percent of rim growth times are less than 1 year, showing that quartz rims have mostly grown in the days to months prior to eruption."
Rim growth isn't easy to detect, but Guilherme Gualda, an associate professor of Earth and environment sciences at Vanderbilt and lead author of the new PLOS ONE paper, suggests the phenomenon would be accompanied by an expansion of the magma chamber, which would result in noticeable changes in the crust's surface.
Gualda and his colleagues say more work is needed to understand exactly what these changes would look like.
The past 100,000 years have featured several supervolcano eruptions -- in Italy, New Zealand and Sumatra. The most recent one happened in 1815. Indonesia's Tambora volcano blew up in what was the largest eruption in recorded history. The super-eruption cause global cooling for a year.
The most famous supervolcano in the United States is Yellowstone. Luckily, researchers say neither it nor any of the others are getting ready to explode.
"As far as we can determine, none of these places currently house the type of melt-rich, giant magma body needed to produce a super-eruption," said Gualda. "However, they are places where super-eruptions have happened in the past so are more likely to happen in the future."