Will We Ever Be Able To Forecast Volcanic Eruptions Like Weather?

Home Will We Ever Be Able To Forecast Volcanic Eruptions Like Weather? SHARE (opens a new tab) QUALIA Will We Ever Be Able To Forecast Volcanic Eruptions Like Weather? It should be possible, but getting there will require a greater understanding of subsurface physics. Celcius Pictor for Quanta Magazine Introduction I n the summer of 1991, Pinatubo, a volcano in the Philippines, self-destructed. The eruption started on June 12, and three days later it culminated in a tremendous explosion. By the time pyroclastic flows — incandescent avalanches of molten rock and gas — tumbled down its sterilized slopes, Pinatubo’s peak had been obliterated and replaced by a 2.5-kilometer-wide chasm. The eruption killed more than 800 people, mainly because roofs, weighed down by rain-saturated ash, collapsed. But it could have been so much worse (opens a new tab) : About 250,000 people, across multiple cities and a sprawling U.S. Air Force base, lived in the volcano’s shadow. When Pinatubo started convulsing and belching steam in April of that year, scientists from the United States and the Philippines deployed an array of instruments that tracked the volcano’s inner tumult. “We didn’t know much about that volcano, and so there was this really rapid geological assessment. And the assessment said, ‘Oh, crap, when this thing erupts, it only erupts big,’” said Mike Poland (opens a new tab) , current scientist in charge at the U.S. Geological Service’s Yellowstone Volcano Observatory. “And that became the basis for a forecast.” By early June, ash and lava were escaping Pinatubo’s flanks, and an evacuation was ordered, just a few days before the cataclysmic hammer fell. It was, in other words, a very close call. Those scientists saved countless lives, but their forecast was more of an educated guess than it might have appeared. It was nothing like a weather forecast; they couldn’t say that on June 12, an explosive eruption was going to occur with anything resembling certainty, nor could they predict the evolution of that eruption. With very few exceptions, this imprecision is true of all well-monitored volcanoes. But volcanology, as a field, has made great leaps since Pinatubo blew its top. The instrumentation is more advanced, machine learning has made interpreting data far more efficient, and scientists have a much better understanding of the magmatic plumbing that drives volcanism. That’s prompted me — as a professionally trained volcanologist who now writes a lot about the field — to wonder: How close are we to forecasting volcano behavior the way we forecast the weather? In this award-winning image, photographer Alberto Garcia captured a truck fleeing the cataclysmic eruption of Mount Pinatubo in the Philippines. Alberto Garcia Today, we know that a storm of a certain magnitude will fall on a specific city in a few days’ time. Will scientists ever be able to say that a week from now, a certain volcano has an 80% chance of erupting in a particular way — with lava gushing, with a certain explosive force, with pyroclastic flows that will travel down its western flank? I asked around, and I found both skepticism and a surprising degree of optimism. “The short answer — otherwise I wouldn’t be doing this — is yes,” said Diana Roman (opens a new tab) , a volcanologist at Carnegie Science in Washington, D.C. Though sky watchers have anticipated the weather for millennia, contemporary scientific prediction of weather is a recent invention (opens a new tab) : The first mathematical equations grounding these models were derived at the start of the 20th century. Today, meteorologists can take a pandemoniac system — Earth’s atmosphere, oceans, and landforms — and make accurate forecasts up to two weeks into the future. Weather affects more people than volcanism — namely, everyone, all the time — but some 800 million people (opens a new tab) live within 100 kilometers of an active volcano, and some (very rare) eruptions can also affect the entire planet. Both weather and volcanism are complex systems that we want to understand, but the problems they present for forecasting are different. “The big difference between [volcanoes] and the weather forecasting is the weather is always happening,” said Jenni Barclay (opens a new tab) , a volcanologist at the University of Bristol in England. The atmosphere is perpetually visible and measurable to meteorologists. “Even they would say they need more observations.” Magma, on the other hand, resides kilometers below Earth’s crust, and at most, active volcanoes erupt once every few decades. Each volcano is also unique. The architecture of the subterranean pathways that funnel magma to the surface, the chemistry of the magma, the cadence of eruptions, and the assortment of eruption styles differ from place to place. And eruptions don’t have just one trigger. The temperature and pressure of the magma reservoir, the weakness of the enclosing rock, the gas and crystal content, the depth of the magma, the regional motion of tectonic plates — these factors all contribute to whether a paroxysm happens or fizzles out. “Geology is chaotic,” said Marius Isken (opens a new tab) , a geophysicist at the GFZ Helmholtz Center for Geosciences in Potsdam, Germany. But there is order buried in the chaos. Can we find it? A volcanologist from the National Institute of Geophysics and Volcanology in Italy installs a gravitmetry station to measure magma movement within Sicily’s Mount Etna. Tom Pfeiffer/Alamy I imagine volcanoes as orchestras composed of hundreds of different instruments. Forecasting eruptions isn’t about hearing the music. We already do that: Seismometers sense the cracking of rock as magma ascends; ground sensors and satellites can track shifts in the crust, indicating where magma is flowing; gas detectors reveal when magma rises to shallow depths, depressurizes, and emits noxious fumes. The challenge comes in knowing how the symphony will develop to a climax, long before it gets underway. Today, at the most comprehensively monitored volcanoes, the best that volcanologists can normally offer is not prediction but a form of acute caution. Often, alert systems — including those used (opens a new tab) by the U.S. Geological Survey — notify the public if a volcano is exhibiting heightened or escalating unrest. But that doesn’t mean an eruption is imminent. “Only 50% of volcanic unrest that looks like it’s going to be an eruption ends up in an eruption,” said Jessica Johnson (opens a new tab) , a geophysicist at the University of East Anglia in England. On the other hand, some volcanoes prefer to ambush us, even when smothered in instrumentation. Pockets of highly pressurized water trapped just below the surface can be heated by adjacent bodies of magma. If that pocket ruptures, a dangerous steam explosion follows, which can then unleash imprisoned magma. This type of eruption often occurs with no discernible warning signs, and it’s like a land mine going off next to a buried mountain of dynamite. Small eruptions of the Soufrière Hills volcano on the Caribbean island of Montserrat preceded destructive large eruptions in 1997. Peter Cripps/Alamy More predictive detail can come if a volcano has been studied over the course of several eruption cycles. At certain peaks, such as Italy’s Stromboli and Etna volcanoes, which regularly spout fountains of lava, scientists can confidently forecast (opens a new tab) an outburst. “We have systems that can tell us that in a few hours, the volcano will erupt,” said Maurizio Ripepe (opens a new tab) , a geophysicist at the University of Florence. Using seismology and ground deformation measurements, scientists at other volcanoes, including Hawai‘i’s Kīlauea (opens a new tab) and those on Iceland’s Reykjanes Peninsula, can track magma migrating underground with such staggering precision that they know exactly where it will emerge as lava, to within an hour or so. But such precise forecasts are “relatively unusual,” said Tom Winder (opens a new tab) , a volcano seismologist at the University of Iceland. These are frequently active volcanoes, unlikely to produce a major explosive event, and people in surrounding communities generally know to be wary of them. In most other cases, the earliest warning times — perhaps an hour or so before the eruption — aren’t always enough to get people to safety. Forecasting eruptions is a big ask because volcanoes cannot be reduced to simple models. They’re baroque geologic beasts with hidden, labyrinthine plumbing. Twenty years ago, during my first year as a geoscience undergraduate, a lecturer told me that predicting when and where the next major eruption would take place was a pipe dream — the implication being that volcanoes are far too idiosyncratic and mercurial to have much in common with one another. That comment felt off even then. After all, they are all vessels of immense pressure and heat. Their schematics may differ. But molten rock flows through all of them, and eventually, something cracks, breaks, and explodes. There were many signals that Mount St. Helens was going to erupt in 1980, but the form of the eruption was unexpected. The event led to the development of more sophisticated monitoring systems in the United States. Jamie Marshall/Tribaleye Images Everyone I spoke to agreed that scientists still need to crack a vital piece of the volcano forecasting puzzle. “We don’t even fully understand the underlying physics,” Roman said. What causes a magma reservoir to transition from a stable state to catastrophic failure? “They have to have shared physics,” she said. If those underlying equations can be discovered, perhaps we can apply them to all volcanoes and output values that tell us, with high accuracy, when the next eruption is due, and what its shape may be. Scientists have already identified some of these governing equations, but they only apply after eruptions have begun. Using more than a century of observations, researchers have largely derived the physics of volcanic hazards — particularly lava flows and pyroclastic flows. For examples, the Navier-Stokes equations, which describe how fluids of all kinds move, have been successfully applied to both of these hazards, while the heat equation (opens a new tab) reveals how and when these volcanic fluids cool down. Today, they allow experts to predict, for specific volcanoes, where outpourings will emerge, how far the different kinds of flows will reach, and how quickly it will all happen. This work saves lives, but it’s a fraction of the forecasting dilemma. Using our weather analogy, this is like saying, “Once the rain starts to fall, we can forecast what watersheds might flood,” Poland said. Knowing when the storm will start requires getting at the subsurface physics of magma reservoirs. For now, eruption warnings are based on recognizing patterns in measurable geophysical signals, such as an escalation of seismic activity, that precede eruptions. But correlation isn’t enough for prediction if the patterns aren’t consistent, which is often the case. “What we’re trying to do is looking at the causative relationships there … to understand the physics,” Johnson said. “If you understand what those patterns mean, [then] when those patterns change, we’re not that stuck.” Johnson is part of a new project named Ex-X: Expecting the Unexpected (opens a new tab) , a multidisciplinary effort led by the University of Bristol to investigate the drivers of dangerous volcanic escalations. Researchers are focusing on the volcanoes of the Eastern Caribbean, which erupt relatively frequently and can quickly transition from effusive-style, lava-heavy eruptions to sudden, catastrophic, explosive ones. La Soufrière, on the island of St. Vincent, provided a recent example of this: In December 2020, the volcano began expelling a viscous mass of lava, which continued for several months. Then multiple explosions threw pyroclastic flows down its slopes. The eruption of Pinatubo in 1991 left a 2.5-kilometer-wide caldera where the summit has once been. It is now Lake Pinatubo. T. J. Casadevall/U.S. Geological Survey As part of this work, hundreds of seismometers, as well as networks of fiber-optic cables, will be used to record even the tiniest of earthquakes, during periods of tranquility and unrest. This monitoring effort will be aided by machine learning programs that will be taught to identify minute shifts in the seismic soundtrack of these volcanoes. In recent years, these programs have been used to process a huge volume of data far more proficiently and efficiently than scientists can manage alone. This work has already revealed myriad previously hidden magmatic pathways beneath volcanoes while also permitting scientists to track, almost in real time, magma barreling through the crust. The idea of Ex-X is to gain unprecedented detail on how tiny changes in the behavior or position of magma can lead to eruptions. Those insights can, in turn, illuminate some of the underlying physics. All these Caribbean volcanoes, diverse though they may be, could have a shared set of fluid dynamics equations. However, seismology won’t be enough by itself. “We lack the physical understanding of what exactly is going on in a magma chamber,” Poland said. What causes the unstoppable nucleation of bubbles within a body of magma, which can propel hot, buoyant magma through the crust above with soda can–like effervescence? What combination of molten rock, crystals, and gas is primed to trigger an eruption? What drives an eruption to switch from expelling oozing lava to blasting ash and rock into the sky? Geochemistry is essential to this effort, too. Today, scientists scoop up lava or ash, fresh or ancient, around volcanoes — both during an eruption and in the interregnum between them — to identify subtle changes in chemical makeup. Scientists use sophisticated numerical models to simulate volcanic viscera, but this is still educated guesswork. Laboratory experiments, though, may be able to ground these models. Replicating the most extreme phenomena in laboratory settings is not easy. But in successful experiments in the fall of 2025, scientists re-created the conditions (opens a new tab) present at the birth of planets, complete with simulacra of magma and miniature hydrogen atmospheres. “You can’t just make a magma chamber at the surface of the Earth,” Poland said. “But we’re a heck of a lot closer to that sort of thing than we were a while ago.” Ideally, volcanologists want to try something else truly ambitious: “Drill all the way down to where there is some magma sitting at depth, and really see these processes in situ, rather than just seeing the results of them,” Winder said. That is one of the objectives of the Krafla Magma Testbed (opens a new tab) in Iceland. This literally groundbreaking facility is set to become the world’s first direct magma observatory.  “There’s no reason we can’t think that at some point in the future, we can have volcano forecasts that are like weather forecasts,” Poland said. But deriving a unified theory of volcanism will require a geologic Manhattan Project. First, a constellation of highly diverse volcanoes will need to be slathered in geophysical instrumentation and consistently monitored over multiple eruption cycles — meaning many decades. “You would like to think, OK, volcanoes are pretty well monitored. But they’re not,” Roman said. “There’s a handful of Cadillac volcanoes that have permanent networks.” Even many of the United States’ most dangerous volcanoes, along the Cascades in the Pacific Northwest (home to the notorious Mount St. Helens (opens a new tab) , for example, and the precarious Mount Rainier (opens a new tab) ), are only partly covered (opens a new tab) in a limited number of sensors. With such a torrent of geophysical and geochemical information, scientists (aided by machine learning) can determine the commonalities that would allow them to derive foundational geophysical laws. Then they can build the archetypal volcano model: one that is very generic but can be layered onto any volcano in the world. The Soufrière Hills volcano in Montserrat buried the small town of Plymouth in 30 feet of mud and ash. Stocktrek Images, Inc. Let’s say you’re concerned about Japan’s explosion-prone Mount Fuji. Scientists could feed its current state of seismicity, its magmatic geochemistry, and the rate at which it’s deforming into the model. Software driven by those governing equations could then virtually fast-forward the volcano toward its most probable eruption date, while also describing the likeliest eruption style and duration. Some experts suspect that there may be several volcano archetypes — ones that prefer to throw out lava, for instance, or the especially explosive kind. Either way, this eruption forecasting concept finds favor with several volcanologists. “That’s definitely the right way to be thinking about it,” said Zach Ross (opens a new tab) , a geophysicist and machine learning researcher at the California Institute of Technology. But skepticism about accurate forecasting remains. “At the moment, I can only imagine it in exceptional circumstances,” Winder said, citing volcanoes that erupt with great frequency, like those in Hawai‘i or Iceland. Other people I spoke with are more sanguine, suggesting that while certain volcanoes will always be troublesome — those that erupt once every few centuries, for example, or those that seem to go from silent to violent in a matter of hours — many eruptions should be forecastable. “What we’re really missing is more data. We have not really observed that many different systems going off,” Isken said. “But I think that gap will fill over time.” Roman is part of the in-development Subduction Zones in Four Dimensions project, or SZ4D (opens a new tab) . If sufficiently funded, this international effort will carry out an intense monitoring campaign along various subduction zones — vast areas where one tectonic plate dives underneath another, including sites in Chile, Alaska, and the Cascades (opens a new tab) — to study the triggers of major landslides, earthquakes, and eruptions. She hopes that the underlying physics leading to each of these hazards will emerge. SZ4D would be a colossal scientific undertaking. But similarly mammoth endeavors were needed to understand how the weather works, and how Earth’s climate is rapidly changing. You’ve got to start somewhere. “It’s time for a big push,” Roman said. Every day, volcanologists perform scientific miracles to protect millions of people from eruptions. It’s thrilling for me to imagine a future in which people get not just hours, but days or even weeks to get themselves out of harm’s way. Also in Physics What Causes Lightning? The Answer Keeps Getting More Interesting. ATMOSPHERIC SCIENCE What Causes Lightning? The Answer Keeps Getting More Interesting. By CHARLIE WOOD MAY 6, 2026 3 Physicists Discover the Most Complex Forms of Ice Yet MATERIALS SCIENCE Physicists Discover the Most Complex Forms of Ice Yet By SHALMA WEGSMAN APRIL 27, 2026 3 Quantum ‘Jamming’ Explores the Truly Fundamental Principles of Nature QUANTUM CRYPTOGRAPHY Quantum ‘Jamming’ Explores the Truly Fundamental Principles of Nature By MATT VON HIPPEL APRIL 17, 2026 3 Comment on this article Quanta Magazine moderates comments to facilitate an informed, substantive, civil conversation. Abusive, profane, self-promotional, misleading, incoherent or off-topic comments will be rejected. 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