Crystals Can Help Reveal Hidden Behavior Of Kilauea Volcano

Scientists struggling to understand how and when volcanoes might erupt face a challenge: Many processes take place deep underground in lava tubes bubbling with dangerous molten Earth. During the eruption, any underground markers that could have offered clues leading to an explosion are often destroyed.

But by taking advantage of observations of tiny crystals of the mineral olivine formed in a violent eruption that took place in Hawaii more than half a century ago, researchers at Stanford University have found a way to testing computer models of magma flow, which they believe could reveal new information. on past breakouts and perhaps help predict future ones.

“We can actually infer quantitative attributes of the pre-eruption flux from this crystal-clear data and learn more about the processes that led to the eruption without breaking through the volcano,” said Jenny Suckale, assistant professor of geophysics. at Stanford’s School of Earth, Energy. And environmental sciences (Stanford Earth). “It is for me the holy grail in volcanology.”

The millimeter-sized crystals were discovered buried in lava after the Kilauea volcano erupted in Hawaii in 1959. Analysis of the crystals revealed that they were oriented in a strange, but surprisingly consistent pattern, which, according to Stanford researchers, was formed by a wave in the underground magma that affected the direction of the crystals in the flow. They simulated this physical process for the first time in a study published in Scientific advances Dec 4

“I always suspected that these crystals were much more interesting and important than what we attribute to them,” said Suckale, lead author of the study.

detective work

It was a chance encounter that prompted Suckale to act on his suspicions. She got a glimpse while listening to a presentation by a Stanford graduate student on microplastics in the ocean, where waves can cause non-spherical particles to assume a consistent disorientation pattern. Suckale recruited the lecturer, then with a doctorate. student Michelle DiBenedetto, to see if the theory could be applied to the odd crystalline orientations of Kilauea.

“It is the result of the detective work of appreciating the detail as the most important piece of evidence,” Suckale said.

With Zhipeng Qin, a geophysical scientist, the team analyzed slag crystals, a dark, porous rock that forms when magma containing dissolved gases cools. When a volcano erupts, liquid magma – known as lava once it reaches the surface – is shocked by the cooler atmospheric temperature, quickly trapping natural olivine crystals and bubbles. The process takes place so quickly that the crystals cannot grow, effectively capturing what happened during the eruption.

The new simulation is based on the crystalline orientations of Kilauea Iki, a pit crater located next to the main caldera on the summit of Kilauea volcano. It provides a basis for understanding the flow of the Kilauea Conduit, the tubular passage through which hot magma beneath the ground rises to the Earth’s surface. Because the slag can be blown several hundred meters from the volcano, these samples are relatively easy to collect. “It’s exciting that we can use these very small-scale processes to understand this huge system,” said DiBenedetto, the lead author of the study, now a postdoctoral researcher at the Woods Hole Oceanographic Institution.

Catch a wave

In order to remain liquid, the material of a volcano must be constantly in motion. The team’s analysis indicates that the strange alignment of the crystals was caused by the magma moving in two directions at once, with a flow directly above the other, rather than flowing through the conduit. in a constant flow. Researchers had previously speculated that this could happen, but a lack of direct access to the molten conduit prevented conclusive evidence, according to Suckale.

“This data is important for advancing our future research on these dangers, because if I can measure the wave, I can constrain the flow of magma – and these crystals allow me to reach that wave,” Suckale said.

Monitoring Kilauea from a hazard standpoint is an ongoing challenge due to the unpredictable eruptions of the active volcano. Instead of continually fleeing lava, it has periodic bursts resulting in lava flows that endanger residents on the southeast side of the Big Island of Hawaii.

According to the researchers, tracking crystal disorientation through the various stages of future Kilauea eruptions could allow scientists to infer the conduits flow conditions over time.

“Nobody knows when the next episode is going to start or how bad it’s going to be – and it all depends on the details of the dynamics of the conduit,” Suckale said.