“Ring of Fire: BIG ONE fears mount after Guatemala eruption”
That was the headline in the Daily Express yesterday after Guatemala’s Fuego volcano erupted, killing 25 people and injuring hundreds more. In May, the paper ran a similar story in response to the eruption of Hawaii’s Kilauea peak:
“Hawaii volcano eruption: Is a BIG ONE on its way? What was the 1790 explosion?”
Both articles acknowledge that experts are sceptical of the ‘Ring of Fire’ and ‘Big One’ fears.
So what’s going on? FactCheck takes a look.
Does the Ring of Fire have the ring of truth?
Whenever a volcano erupts or an earthquake hits somewhere around the Pacific Ocean, you’ll probably hear reporters refer to the ‘Ring of Fire’.
Colin Macpherson, professor of earth sciences at Durham University explains: “[The] Ring of Fire is a geographic description of the fact that anywhere you go around the margins of the Pacific Ocean, you find volcanoes. There are some gaps but mostly there is a chain of volcanoes that runs much of the way where there is land.”
Here’s what that looks like on a world map, with areas in orange highlighting regions of increased tectonic activity.
So does that mean that earthquakes and eruptions around the Pacific edge are linked to one another?
Professor Macpherson points out that this is where the term Ring of Fire can be misleading: “The idea that there’s a single chain of volcanoes that are somehow linked to one another is not really a concept that people who study volcanoes would adhere to.”
Ken Rubin is professor of volcanology at the University of Hawaii. He explains: “For the most part the eruptions are caused by local factors at that volcano. There are occasions where one large geophysical event, like an eruption or earthquake, have been suspected to set off another large event a another site.
“While it is easy to prove that events are correlated in time, it is much more difficult to determine if events are causally related. I think it is human nature to look for connections between large events – addressing our curiosity is really what drives science in the first place.”
In other words, it’s true that the Pacific coast is particularly prone to earthquakes and volcanic eruptions – but that doesn’t mean that those events are all linked.
And what about the ‘Big One’?
Coverage of the recent eruptions in Guatemala and Hawaii has seen some journalists talk about the elusive ‘Big One’ – the idea that there might be a massive volcanic eruption on its way.
Like the Ring of Fire, this concept does have some basis in truth, but can be misleading.
Professor Macpherson again: “Those of us who study volcanoes all expect that there will be a very large volcanic eruption – perhaps in our lifetime, perhaps not.”
But when it comes to predicting when that might happen, it gets much hazier: “Just as we don’t see the Ring of Fire being a linked series of volcanic events that you can predict, there isn’t really a concept of being able to predict a Big One because of a precursor.”
“The concept of a Big One is not one that researchers would use. We would tend to look at individual volcanoes. Making predictions about one volcano from another one has to be done with very careful thought.”
Professor Rubin explains why the idea of a Big One is attractive to some reporters: “Sometimes the media can pick up on a fact here or there and over-emphasize it, or perhaps change the meaning a bit.
“We have never seen evidence in the past for [the Big One], despite some individually very large eruptions in the past 100,000 years. Over the course of the last century or so, there have been several quite large eruptions […] But there really isn’t any strong evidence that any of these were related to each other.”
Can two high-profile eruptions so close to each other really be a coincidence?
Tectonic events happens all the time, but fairly obviously, the media only covers the ones that are newsworthy.
As Professor Macpherson says, “Hawaii is in an iconic location and the type of eruption is photogenic.” You only need to see the images of lava flowing through residential streets and destroying homes to understand his point.
Photo credit: USGS / HANDOUT
Meanwhile, as Professor Rubin points out, the eruption in Guatemala this week was tragic because of the loss of life.
These factors have attracted the world’s attention to Hawaii and Guatemala.
Our experts estimate that between 10 and 20 volcanoes are erupting somewhere in the world at any one time. These events get less coverage for several reasons – usually because they happen in uninhabited areas, including underwater, or because they haven’t involved any loss of life.
That’s not to say that the two recent eruptions are geologically uninteresting, though.
Professor David Pyle of Oxford University told us that “both Kilauea [Hawaii] and Fuego [Guatemala] have experienced dramatic changes in activity recently”, with a significant shift of magma underneath the Hawaiian volcano and “more vigorous” activity at the Guatemalan peak.
But Professor Pyle is keen to stress that while the eruptions and changes have been unusual, “this is just part of the unpredictable pattern of behaviour at any erupting volcano. There are no wider links between the volcanoes, and no expectations of wider consequences for other volcanoes in the Pacific region.”