Volcanoes are surrounded by dramatic stories, from giant underground chambers full of liquid magma to claims that Yellowstone could suddenly unleash a worldwide catastrophe.
But many popular ideas about volcanoes are misleading or simply wrong.
An international team of volcanologists has examined 18 common misconceptions about volcanoes and eruptions.
Their work, published in the Journal of Applied Volcanology, aims to help the public better understand what scientists actually know about volcanic risks.
One surprisingly common mistake involves the “smoke” seen rising from an erupting volcano.
It isn’t actually smoke. Explosive eruptions can release water vapor and other gases mixed with volcanic ash. And unlike the soft ash left after burning wood, volcanic ash consists of tiny pieces of rock, minerals and volcanic glass. These particles can damage aircraft and infrastructure and cause health problems.
Another misconception involves the familiar image of a huge underground magma chamber.
Textbooks and diagrams often show a volcano sitting above a large cave filled with glowing liquid rock. In reality, magma can be distributed through a much more complicated system extending deep into Earth’s crust. Changes in magma don’t necessarily mean a giant reservoir is filling until the volcano finally “overflows.”
Earthquakes around volcanoes are also commonly misunderstood.
A series of earthquakes can provide important clues that something is changing underground, but it doesn’t necessarily mean an eruption is about to happen. Scientists monitor many different signals and combine them to estimate what may happen next.
Even with sophisticated instruments, volcanologists generally cannot predict the exact time, size or duration of an eruption. Instead, they assess probabilities and possible scenarios.
The famous Pacific “Ring of Fire” creates another misunderstanding. Although many earthquakes and volcanoes occur around the Pacific Ocean, the region isn’t one giant connected volcanic system. It contains numerous tectonic plates and boundaries. Two volcanoes erupting around the Pacific at similar times aren’t necessarily connected.
The researchers also warn about dramatic terms such as “supervolcano.”
Yellowstone is frequently associated with catastrophic eruption scenarios, but the largest eruption a volcano produced in the distant past isn’t automatically the most likely thing it will do in the future. Large volcanic systems can experience many smaller forms of activity.
The same caution applies to “mega-tsunami” claims. Volcanoes can cause tsunamis through landslides, collapses or explosions, but that doesn’t mean every unstable volcano is capable of producing a devastating ocean-wide wave.
The researchers also addressed claims that volcanoes are responsible for modern global warming. From 2005 to 2015, volcanic carbon dioxide emissions were equivalent to less than 2% of the amount humans release each year. Large explosive eruptions can actually temporarily cool the planet by sending particles and gases high into the atmosphere.
Social media has made accurate information even more important. Dramatic eruption videos can quickly spread without context, and old footage may be presented as a new event.
The researchers say misinformation can cause unnecessary panic, but it can also create the opposite problem. If people repeatedly encounter exaggerated warnings, they may eventually ignore genuine danger.
Volcanoes are unpredictable and potentially deadly, but scientists know far more about them than dramatic headlines often suggest. Understanding what monitoring can—and cannot—tell us may ultimately help communities respond more effectively when a real volcanic crisis begins.
