Scientists have developed a new technique to forecast how a volcano will behave – by zapping its ‘rocky road’ lava with lasers.
The pioneering method involves the catchily-named ‘laser ablation inductively coupled plasma quadruple mass spectrometry’. However, a simpler way to imagine it is laser eye surgery.
Volcanoes are brimming with magma, molten rock that has seeped up from the Earth’s mantle. When a volcano erupts, chemical reactions change the make-up of the magma – which is then called lava.
Dr Teresa Ubide, from the University of Queensland, calls magma the ‘computer code’ of volcanoes, providing vital information about how they might erupt and what lava flows may occur. Not all eruptions are accompanied by a lava flow, and there are also different types of flow, depending on the viscosity, or runniness, of the lava.
‘The chemical changes that occur within the liquid portion of the magma during a volcanic eruption are quite incredible,’ said Dr Ubide.
‘The magma is made up of liquid melt, gas and crystals that combine inside the volcano.
‘There are often so many meddling crystals that the magma looks like rocky road, and it’s difficult to observe its chemistry. To get these crystals out of the way, we blast the cooled melt – which is known as the rock matrix – with a laser like those used for eye surgery.
‘Then we analyse the material measuring its chemical make-up.’
Dr Ubide and her team tested the method on samples collected during the 85-day eruption of La Palma’s 2021 eruption.
‘The eruption covered more than 12 square kilometres, with 159 cubic metres of lava destroying around 1,600 homes and forcing the evacuation of more than 7,000 people – it cost the country the equivalent of around $1.4 billion,’ Dr Ubide said.
‘To understand how volcanic eruptions may evolve and to provide warnings and advice to people, live monitoring data is critical.
‘Earthquakes, ground changes and gas data provide indirect information on what is happening inside an active volcano but the chemistry of the melt is a direct measure of the “personality” of the magma, its behaviour upon eruption and potential impact on populations and infrastructure.
‘The information we gathered during this eruption could help inform volcano monitoring and hazard management in the future.’
The team is now trialling a similar technique on volcanic ash, which can be sampled more readily during a volcanic event.
‘We are excited to collaborate with volcano observatories to implement the method as a monitoring tool,’ Dr Ubide said.
The study is published in the journal Science Advances.