Good news: A team of scientists has discovered that we can predict super volcano eruptions "decades in advance". Bad news: Another team of scientists have discovered that a volcano in Death Valley, California, may explode at any time.
The volcano is the Ubehebe, a large volcanic crater to the north of Death Valley. The team, led by Peri Sasnett of the Department of Earth and Environmental Sciences at Columbia University, have published a paper in Geophysicial Research Letters that shows that it may have been formed much earlier than previously thought. Using the same method used to date moon rocks, Sasnett and his team have discovered that the last explosion occurred only 800 years ago, instead of the previous 10,000-year estimate.
But the worst part is that, according to researchers' observations, the next explosion may occur at any time. Magma has built up under the surface much faster and higher than previously thought. Apparently, we are in the middle of an eruption cycle. They have discovered that these explosions occur in clusters, and right now we're experiencing a brief calm before another storm.
Ubehebe will explode in a phreatomagmatic eruption: the magma pool expands so much that it reaches the water pool deposited over it. This produces steam, which in turn results in a pressure build up until it reaches a point that will cause a violent explosion. Scientists believed that these explosions were not possible during dry periods, but the new research shows that this is not the case at all.
The latest readings have detected a water table just 150m below the surface of the crater. When the magma reaches the water, it will go boom.
Death Valley Park authorities are not worried about it, however. The believe the explosion will not occur without warning — like increasing seismic activity — so no tourists will be incinerated on the spot. The volcano is not big enough to cause damage any nearby city. It will be a great show, however.
Predicting Volcano Eruptions
The good news comes from the Greek island of Santorini; a new paper published in Nature shows that we should be able to predict mega-eruptions decades in advance.
Studying the rocks in Santorini — from the Minoan eruption in the late 1600s BC that led to the legend of Atlantis — a team of scientists has discovered rocks that were formed only 100 years before the eruption. The gestation of that volcano took about 18,000 years, but scientists have discovered that most of the magma build-up took place in the century that immediately preceded the explosion. As lead researcher Professor Tim Druitt told the BBC:
What we're finding is that there's an acceleration phase of magma build-up on a time scale of a few decades, and that's surprisingly short given the thousands of years of repose that have preceded that eruption.
Using that information, Druitt says that mega-volcano calderas "should be monitored using highly sensitive modern instruments in order to pick up these deep signals which may suggest reactivation". If those instruments detect a quick build-up, then it's time to worry and start moving people around. This will give us some time to at least save most of the population from the immediate effects of an eruption; the effects a super-volcano like the Yellowstone's caldera will have on Earth's climate at a global scale are another story altogether. [Geophysical Research Letters and Nature via Sciency Thoughts, USA Today and BBC News]
Ubehebe crater image and diagram by Jake McDonald's