Looking for ‘metal soup’ beneath volcanoes

When thinking about the relationship between volcanoes and the Net Zero transition, geothermal energy might readily spring to mind. But volcanoes could offer another important resource: critical metals needed for low-carbon technologies including solar panels, wind turbines and electric vehicles. Deep beneath volcanoes, metals released from magma can become concentrated in hot, salty fluids known as magmatic brines. As these dense fluids become trapped in the surrounding rock, they can form underground reservoirs or ‘brine lenses’.

🔎🍲 In other words, a kind of underground ‘metal soup’ hidden a few kilometres beneath the Earth’s surface.

The challenge... finding these brine lenses. Exploration drilling can confirm whether these hidden reservoirs contain high-salinity, metal-rich brines but, drilling in high-temperature environments close to active volcanoes is challenging to say the least!

🤔 So, how do you go looking for ‘metal soup’ without drilling for it first?

That is where new research from Bogiatzis et al. comes in. Using seismic waves from earthquakes to image beneath Soufrière Hills Volcano in Montserrat, the researchers identified a zone around 2 km beneath the surface that is likely to be a magmatic brine reservoir. By combining P- and S-wave seismic imaging with the locations of earthquakes, the researchers were able to distinguish this likely brine reservoir from magma and shallower hydrothermal features.

While seismic imaging cannot tell us directly how much metal the reservoir contains, the findings demonstrate how geophysical imaging could help identify these difficult-to-reach reservoirs and, importantly, help de-risk future exploration drilling.

📖 Read the full publication: Seismic Exploration for Magmatic Brine Lenses: An Example From Soufrière Hills Volcano, Montserrat