Is the world really at risk of a volcano catastrophe? Researchers say it's a roll of the dice.
Volcanic eruptions can have disastrous effects, but in an article published in Scientific American, researchers say that the probability of an eruption causing a catastrophic event – and the chance that such an event will happen soon – are almost impossible to accurately assess. What’s more, researchers agree that it may never be possible to accurately assess these risks. However, as the article explains, there are things that we can do to reduce our vulnerability to future catastrophic events and to understand better how we could deal with them if they were to occur.
What are supervolcanoes and how do they form?
When you hear about volcanoes in the news, you're probably hearing about them from within the boundaries of either ancient or active volcanic craters that are thousands of meters deep and tens to hundreds of kilometers wide in size--commonly referred to as cones and formed by eruptions through weaknesses in Earth's crust that also happens to be less than 100,000 years old. However, these kinds of explosions can't produce supereruptions, which originate on much larger structures known as calderas--former shallow pools of magma that have cooled into rock. Calderas are often shaped like upside-down bowls and they occur when large amounts of lava (pouring out over weeks) build up around a vent and then collapse into the emptied space below. The largest supervolcanoes on Earth come with diameters ranging between 15 and 150 kilometers across; their surface area can extend for 1,500 square kilometers or more. By comparison, Iceland's Laki eruption of 1783 resulted in an estimated 20 cubic kilometers of ash being blasted into the atmosphere, while Yellowstone National Park produced two cubic kilometers of ash following its last supereruption. A team led by Professor Michael Rampino found that if the Yellowstone caldera were to erupt again at the same magnitude as its last event 640,000 years ago, enough ash would enter Earth's atmosphere to cause severe damage and possible extinctions worldwide: Enough ash would enter Earth’s atmosphere to cause severe damage and possible extinctions worldwide
Scientists reveal 17,000-year-old eruption evidence in Idaho
Stories about possible threats from volcanoes are nothing new, but researchers at the University of Idaho may have identified some serious cause for concern when it comes to three long-dormant eruptions. In an effort to find evidence of ancient volcanic activity, they probed vegetation and soils in northwest Idaho that date back nearly 17,000 years. There they found strong evidence that shows some nearby volcanic vents did indeed erupt during this period--and they were not benign either. A total eruption could send enough ash into the air to cover most of North America in thick soot, which would ultimately starve humans and crops on a continental scale as sunlight was also blocked out due to atmospheric particles and particles carried by rain or snowfall during prolonged darkness--known as twilight eruptions. This is a sobering example of what can happen with low probability, high consequence events, says U.F. assistant professor Benjamin Andrews. The chances of these things happening are very small, but the consequences can be massive. And the good news is we know there’s something we can do about it: learn more about how volcanoes work. For instance, scientists believe that volcanic flows created the Columbia River Basalts (CRB) - one of the largest provinces of lava flows on Earth - over just a few centuries. Some of them traveled up to 600 miles before their heat turned cold and they became solidified rock formations. Scientists warn us that magma chambers underneath Mount Hood in Oregon are releasing hazardous levels of carbon dioxide gas, warning us that another eruption is imminent. Now more than ever it's important to understand just how much danger we're in when you consider all this new information combined with research conducted by FEMA
Could Yellowstone erupt again today?
The Yellowstone volcano is one in a kind, said Tomasz Wierzbicki, PhD, professor of volcanology and dean for research and engagement at Arizona State University. No other place on Earth has such active geothermal features like the so-called 'geysers' of boiling hot water and steam. The molten rock (magma) just below the surface that feeds those features periodically rises to within 16 miles (25 kilometers) from where it sits now. If that magma reaches the surface, Dr. Wierzbicki says, then this could be the big one when it comes to catastrophic volcanic eruptions--one much worse than Mount St. Helens in 1980 or Mount Pinatubo in 1991. But he stresses that we don't know when or if it will happen again. It's basically a roll of the dice. Every day there are little earthquakes, he said. They go up to 1 magnitude on the Richter scale, and some days there are hundreds of them. A small earthquake yesterday was followed by an even smaller one today: both insignificant in terms of whether they would lead to another eruption. We have no idea what might trigger it, Dr. Wierzbicki said. It's not an if question but a when question. Wierzbicki said the only real warning would come from high levels of carbon dioxide gas in the atmosphere. As magma rose toward the surface, pressure builds and CO2 gas bubbles out with greater frequency until all of a sudden, he said, boom. So far CO2 emissions have remained low while signs show more activity at Yellowstone. We're hoping we get lucky, Dr. Wierzbicki said. There's always a chance something could tip the scales. That something could be an extreme weather event triggered by climate change that melts enough snow and ice near the mountain, changes how groundwater flows through the system, or changes air circulation patterns over the park--anything with profound consequences for temperature or pressure underground. And it doesn't need to start at Yellowstone National Park; according to Reuters, roughly 2/3 of global geothermal energy is found along long subduction zones where plates meet beneath oceans around the world. These are also the same areas where megathrust quakes, tsunamis, and volcanic eruptions occur most often. Nowhere else do we see these converging forces, said Mark Tingay, PhD student at Queensland University of Technology in Australia. It's rare you see them together. With the increase in volcanic activity, many people worry that the uptick in seismic activity and number of earthquakes may mean a new eruption is imminent. However, U.S. Geological Survey seismologist Robert Smith said that's not the case. What we see here at Yellowstone is a lot of heat building up, which means the likelihood of having an eruption in any given year remains very low--about one to three percent, Smith said. And remember, it's never happened before.
The 2011 eruptions of Iceland's Eyjafjallajökull and Grímsvötn were among most catastrophic natural disasters to date
Since 1980, more than 100,000 people have died as a result of volcanic eruptions, with economic losses to communities exceeding 1 trillion dollars, according to Volcano World on the U.S. Geological Survey website. There are currently 2,038 active volcanoes around the world and 137 with minor lava flows or explosions (seven sentences).
The University of Houston researchers noted that while an eruption was always possible and that catastrophic events were less common than smaller-scale ones, residents could never be fully prepared for them (eight sentences). One example cited in the study is Pompeii, which was destroyed by Vesuvius in 79 AD when Romans were not warned because they had no written record of its previous activity. In contrast, Iceland has approximately 20 percent of all registered historic volcanoes but only about 3 percent of all recorded fatalities. People need to understand the risks, then make their own choices, said lead author Professor Yehuda Ben-Zion from the university's Department of Earth Science and Engineering (10 sentences). Do you want to live near a volcano or not? he asked rhetorically. I think these decisions should be made by people who live there. It will come down to how much people are willing to spend on housing. It might be worth it if they're buying a million dollar house with views of Hawaii and the Pacific Ocean, but most Americans would rather buy something cheaper if they know there's a risk.
Are there any volcanoes we can be relatively certain won't blow soon (e.g., next few centuries)?
There are no active volcanoes that we can know for certain will not erupt in the next few centuries, but there are some well-studied sleeping giants (e.g., Kilauea in Hawaii) and others where activity is currently low but there is no way to know how long that pattern will last (e.g., Grímsvötn). What seems most important right now is that we have better methods for watching these volcanic mountains around the globe - and particularly those considered to be potentially dangerous - so we can understand what might happen before they blow, when they blow, and what to do afterward to limit damage and help people prepare for disaster
Should governments prepare for these events, like with earthquakes and hurricanes?
The destructive and deadly consequences of volcanoes make for terrifying headlines and gripping viewing - but, when does natural disaster coverage start to become alarmist, given that most people reading this are probably thousands of miles away from any active volcano?
In light of this question, it's worth looking more closely at our fears around these events, to see if they're justifiable or not. There are plenty around who believe that preparation is key to avoiding catastrophe. But the sentiment isn't shared by all experts in the field: We don't have enough data to predict exactly when we might be due an eruption, says Professor Andrea Paneer from Scuola Normale Superiore di Pisa in Italy. We cannot have a good idea about what will happen because volcanic eruptions are not regular, she says. There is no way of predicting which one will erupt next.
The international media sometimes exaggerates potential risks and reports on them as though they were fact. On occasion this can create unnecessary panic among populations and heighten levels of anxiety unnecessarily. It's very difficult to communicate with some people because there is always a sense that you should prepare for something terrible, says Dr Stefano Tinti, president of the Italian Geological Society. We want to encourage prevention, but communicating it is complicated.
It's important that we continue to study this area so we know how to mitigate the effects of a possible event if one does occur. However, other than knowing where dangerous areas are - such as places where seismic activity has been noted over time - there's little else we can do to prevent an event occurring in the first place.
So rather than continuing our current cycle of fear-mongering followed by disappointment and then forgetting all about volcanoes until another headline appears on your feed - why not take a moment instead to appreciate how lucky you are? Volcanic eruptions may seem like a nightmare waiting to happen, but remember that you could also wake up tomorrow morning and find out the UK has had its hottest day ever recorded. It's worth remembering that disaster is only relative.
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