Scientists unearth explosive threat in ‘placid’ volcanoes

VOLCANOES deemed to be “boring” because they are not prone to violent eruptions hide underground secrets which could cause them to “go rogue”, according to a new study.

An international team of volcanologists made the assertion after studying two volcanoes in remote islands on the Galapagos archipelago which have erupted for millions of years. The volcanoes spew molten basaltic rock, which generally flows down their flanks at the speed of walking pace.

But experts found their underground magmas were extremely diverse with chemical compositions similar to notoriously violent volcanoes such as Vesuvius and Mount St Helens.

After reconstructing the chemical and physical properties of the magmas stored below the Galapagos for the first time, researchers say they have the potential to generate “explosive activity”. Experts added that volcanoes that had only produced gentle eruptions could “go rogue” in the future.

Lead author, Dr Michael Stock, of Trinity College Dublin, said: “This was unexpected. We started the study wanting to know why these volcanoes were so boring and what process caused the erupted lava compositions to remain constant over long timescales. Instead, we found they aren’t boring at all – they just hide these secret magmas under the ground.

“Just because they have always erupted a particular way in the past does not mean you can rely on them to continue doing the same thing indefinitely into the future.”

Experts say the study will improve understanding of the risks posed by volcanoes across the world. Co-author Dr Benjamin Bernard said: “This discovery is a game-changer. It allows us to better understand the behaviour of these volcanoes, which is essential for monitoring and hazard assessment.”

The worst volcanic tragedy on record happened in 1815 when Mount Tambora in Indonesia erupted. It killed more than 90,000 people. Then came Mount Krakatoa in 1883, also in Indonesia. It claimed more than 35,000 lives, mainly due to resulting tsunamis.

The worst eruption of the 20th century is considered to be Mount Pelée in 1902 on Martinique in the Caribbean, which killed around 30,000.

Mount Ruiz in Columbia erupted twice in 1985. A mixture of mud, ash and water raced down the volcano’s slope through river channels. It almost completely buried a town 30 miles away – killing an estimated 25,000.

The study was published in Nature Communications.