How these unremarkable crystals could help predict volcanic eruptions

23 Jan 2018

Image: RossiRobinNice/Shutterstock

Predicting volcanic eruptions is hardly an exact science these days, but some humble crystals could give us a much-needed heads-up.

Geologists and emergency services in affected areas probably wish they had a crystal ball to see when the next volcanic eruption will be, but perhaps the answer could actually lie in crystals themselves.

In a paper published to Nature Communications, two scientists from Trinity College Dublin (TCD) and the University of Queensland (UQ) have found evidence that suggests small crystals in volcanic rocks such as lava may hold the key to better understanding advance warnings of eruptions.

The crystals – which, to the average person, would appear pretty unremarkable – are formed when magma starts moving upwards from depths of up to 30km towards the Earth’s surface.

So, with the help of a laser technique used to examine the interior of the crystals, Prof Balz Kamber (TCD) and Dr Teresa Ubide (UQ) discovered that the crystals contain a memory in the form of growth layers, which look similar to tree rings.

By reading the history of these layers, it could lead to more effective volcanic hazard monitoring, including dormant volcanoes.

Volcanic crystals

The scientists’ research took them to Mount Etna. Image: Dr Teresa Ubide

Must be taken seriously

“They essentially ‘record’ the processes right before the eruption starts. At Mount Etna, we found that the arrival of new magma at 10km depth is a very efficient trigger of eruptions – and within only two weeks,” Ubide said.

“In this case, therefore, Earth tremors at the depth of magma recharge must be taken as serious signs of potential imminent eruptions. At other volcanoes, the method will allow to establish the relationship between recharge depth, recharge frequency and eruption efficiency. This can then help scientists to better relate physical signs of recharge to eruption potential.”

Kamber added that aside from helping us more accurately pinpoint when an eruption will occur, it could also help us to understand the science behind volcanoes that are no longer active.

“The new approach may also prove useful for studying volcanoes that have remained dormant, such as the currently erupting volcano on Kadovar Island, Papua New Guinea,” he said.

“For many volcanoes, there is no eruption history, but geologists can collect lavas from past eruptions and study their crystals.”

Colm Gorey was a senior journalist with Silicon Republic