U of A researcher to monitor unstable volcano in Chile

An Edmonton researcher travelling to Chile wants to understand what makes volcanoes tick — beyond the simple fact they have cores of liquid hot magma.

Martyn Unsworth, a geophysicist at the University of Alberta, is interested in Laguna del Maule, a volcanic field undergoing an unprecedented level of uplift. The Earth is shifting upwards by 30 centimetres per year, suggesting volcanic unrest.

“It’s telling us lava molten rock is moving underneath the surface,” Unsworth said, noting that in comparison other volcanoes grow by millimetres or centimetres every year. “The speed is off the scale.”

Laguna del Maule isn’t the picture postcard version of a volcano with a pointed top and broad base. Instead, it’s formed by a small ring of volcanoes that straddle the Chilean-Argentine border.

It’s one of thousands of volcanoes in the Andes mountain range, but ongoing signs of unrest make it a particular concern to Chilean authorities.

“(Researchers) have to prioritize where they put their sensors,” Unsworth said. “With GPS you can actually measure the height of a volcano from space ... you scan thousands of volcanoes much more efficiently.”

“Volcanoes are all basically concentrated in places where you have boundaries of tectonic plates ... You see this along South America up through Mexico and it continues up through Oregon and Washington.”

Unsworth will use tools that he likens to medical imaging scanners.

Using radio waves, he will essentially take X-rays of what’s happening beneath the Earth’s surface to determine how the magma would erupt from the volcano — in an impressive explosion or a slow ooze of lava.

“The question is when,” he said, noting it will be his third trip to the field site.

Although seismic activity can be monitored, volcanic eruptions are unpredictable — one volcano in Chile under surveillance gave only two hours warning before unleashing a 12,000-metre ash column, he said.

Chile is a hotbed of earthquake activity as well, which can trigger eruptions.

“It’s like shaking a Coke bottle up,” he said. “And as magma forces its way up there will be small earthquakes.”

Eruptions in the region, about 400 kilometres south of Chile’s capital city Santiago, have spillover environmental effects on neighbouring Argentina.

“Whenever there’s a massive eruption, the ash blows into Argentina,” he said.

Unsworth, who plans to publish his findings, will be in Chile from Feb. 4 to March 1.