Kilauea Volcano Is the Most Dangerous in America, and This Year's Eruption Was the Biggest in 200 Years

In April, Hawaii's Kilauea volcano started to erupt, and it did not stop until August. Over this time, magma drained from the volcano and the caldera collapsed. Hundreds of homes were destroyed and, according to the Honolulu Star-Advertiser, recovery from the eruption could cost $800 million.

In a study published in Science, researchers have now said the 2018 lower East Rift Zone eruption was the largest "for at least 200 years." The team, led by Christina Neal from the United States Geological Survey, looked at the activity at the volcano over the past year to understand the main characteristics of this prolonged eruption.

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The Pu'u 'Ō'ō vent at Kilauea collapsed on April 30, allowing magma (the hot fluid material below or within Earth's crust from which lava is formed) to pour out. Over the next week, fissures opened, leading to a crack that extended over 4 miles. At the start of May, a 6.9 magnitude earthquake caused the fault to slip, and lava started to erupt at a rate of 100 cubic meters (3,531 cubic feet) per second. Eventually, lava covered an area spanning 13.7 square miles.

Before this event, Kilauea had been fairly consistent for more than 30 years. However, Neal and her co-authors note that in the middle of March, the ground around Pu'u 'Ō'ō started to deform—probably from the accumulation of magma. Previous events like this have led to new eruptive vents appearing within a few miles.

However, over March and April pressure continued to build and eventually the lava pond at Pu'u 'Ō'ō overflowed. The whole plumbing system of the volcano was affected. On April 30, data indicated rapid changes were taking place in the magma system and, on May 3, the first of 24 eruptive fissures opened up. In total, 62 collapse events took place between May and August.

It appears a structural failure at Pu'u O'o forced magma to escape along the rift zone, which provided the catalyst for the other eruptions.

Researchers said the eruption provided an unprecedented view into Kilauea's volcanic system—and they are still learning from the data produced from it. This is hugely important, as in October, the United States Geological Survey's National Volcanic Threat Assessment listed Kilauea as the most dangerous volcano in the country.

Pete Rowley, a volcanologist at the U.K.'s University of Hull who was not involved in the study, said the findings were highly valuable for the monitoring of Kilauea: "Having very high resolution ground deformation measurements before, during and after eruption is exceptional, and will help us to understand how magma behaves in shallow settings better—and in the Kilauea plumbing system in particular," he told Newsweek.

Concluding, Neal and her team said the success of the Hawaii Volcano Observatory's ability to detect and forecast the eruption provides a "strong argument for continuous and intensive ground-based monitoring" of the volcano in order to understand the risks it poses.

Kilauea Volcano
Lava from a Kilauea volcano fissure advances up a residential street in Leilani Estates, on Hawaii's Big Island, on May 27. Mario Tama/Getty Images