A study led by the University of Queensland has discovered that lava samples have disclosed a new reality about the geological make-up of the Earth’s crust, which could have ramifications for early warning systems for volcanic eruptions.
Dr Teresa Ubide, a volcanologist at the University of Queensland, said it was previously thought that cooled lava from so-called ‘hot spot’ volcanoes was ‘pristine’ magma from the Earth’s melting mantle, tens of kilometers below the surface.
Dr. Ubide explained, “This isn’t quite the case — we’ve been mislead, geologically tricked.”
“We’ve thought of hot spot volcanoes as messengers from the earth’s mantle, providing us with a glimpse into what’s going on deep beneath our feet for decades.
“However, the insides of these volcanoes are extraordinarily complicated, and they filter a totally different melt to the surface than we had anticipated.”
“This is because the volcano’s intricate plumbing system drives numerous minerals in the lava to crystallize,” says the author.
The minerals are being recycled by the rising magma, changing their overall chemistry to make them ‘look’ clean, according to Dr. Ubide, which is an essential new piece of the puzzle in understanding how ocean island volcanoes work.
“We observed that hot spot volcanoes filter their melts such that they become highly eruptible at the Earth’s crust’s base, several kilometers beneath the volcano,” she stated.
“Volcanoes can be closely monitored to see when magma reaches the crust’s base, where the filtering processes reach the ‘tipping point’ that leads to eruption.”
“Our findings back up the theory that detecting magma at the crust-mantle interface could signal an impending eruption.”
“This new knowledge brings us one step closer to better volcanic unrest monitoring, which aims to protect people, infrastructure, and crops.”
Some of the world’s most stunning landscapes are made up of hot spot volcanoes, such as the Canary Islands in the Atlantic and Hawaii in the Pacific.
New rock samples from the island of El Hierro, in Spain’s Canary Islands, just south of Morocco, were analyzed by an international team of specialists.
This information was integrated with hundreds of previously released geochemical data from El Hierro, including data from the 2011 and 2012 underwater eruptions.
The findings were then put to the test using data from ocean island hot spot volcanoes all throughout the world, including Hawaii.
Hot spot volcanoes can also be found in Australia, according to Dr. Ubide.
“The Glass House Mountains or the massive Tweed shield volcano, which includes Wollumbin (Mount Warning) in New South Wales, would be extremely recognizable to south-east Queenslanders,” she said.
“Unlike most other volcanoes, which form when tectonic plates collide, such as the Ring of Fire volcanoes in Japan or New Zealand, or when tectonic plates move away from one other, such as the Atlantic Ocean, hot spot volcanoes can form ‘anywhere.'”
“Millions of years ago, the hot spot volcanoes in southeast Queensland were active.”
“They created massive amounts of magma and serve as great laboratories for studying the origins of volcanism.”
“There are even dormant volcanoes in South Australia that could erupt with little warning, and improved geological indicators for early detection would be beneficial.”