New instrument for mapping lava flows to inform disaster response

For the millions of people worldwide who live near active volcanoes, accurate data is needed to estimate the extent of possible damage after an eruption, to inform evacuation plans and disaster response efforts.

But the nature of volcanic eruptions means that collecting data on lava flows can be incredibly challenging.

To address this gap, researchers have developed a new tool for measuring the viscosity of active lava flows, which could increase understanding of and improve models of its movement.

Described in a paper in the journal Review of Scientific Instruments, the device is lightweight and durable.

“In places like Iceland or Hawaii, [which] have pretty frequent lava eruptions that impact infrastructure like roads and communities, there is uncertainty involved with the estimation of where the lava may travel and how quickly it may go there,” says study author Martin Harris of the University at Buffalo in the US.

The behaviour of lava flows is mostly determined by its viscosity. A low-viscosity fluid, like water, flows fast while a highly viscous fluid like molasses, flows more slowly.

The issue, according to Harris, is that viscosity measurements are almost always conducted in a lab, where experiments are easier and safer, but a key piece is always missing.

“When lava erupts from a volcano, a lot of different gases are trapped as bubbles within the lava,” says Harris.

“When we do measurements in the lab, we cannot put the gas back in. So, what we measure is a representation of the lava without all the different components, and we miss something that influences how the lava can flow.”

The prototype instrument consists of a metal rod attached to a force gauge, and a second rod for measuring displacement. It’s been tested  in a field trial at an active volcano in Iceland.

“We spent almost two weeks accessing different locations around the Litli-Hrútur eruption,” says Harris.

“It was a lot of very long hours in a pretty intense environment, but I think in the end, we were all really impressed and satisfied with the work that we were able to do.”

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