The “extraordinary” three-month eruption of Hawaii’s Kilauea, named yesterday as the most dangerous volcano in the United States, destroyed more than 700 homes and buildings and caused the evacuation of 2,000 people.
Lava burst through more than 20 cracks in the Earth’s crust as well as from the mountain’s summit on the Big Island.
Numerous roads and other infrastructure was damaged, while lava from the volcano reshaped the south-east corner of the island, creating more than 500 acres of new land.
In a blog written by Hawaiian Volcano Observatory scientists and posted on the USGS’s website said: “The 2018 summit collapse and lower East Rift Zone eruption at Kīlauea Volcano were dramatic and, for many Island of Hawaii residents, tragic events.
“As with all eruptive crises, these events offered exceptional opportunities to learn more about how volcanoes work and to answer some ‘bigger picture’ questions.
“This latest chapter in Kīlauea’s remarkable story is still unfolding, but already it’s clear that 2018 marks a watershed for volcano science, not only in Hawaii but also worldwide.”
The summit collapse which “profoundly reshaped” the volcano’s caldera and the Halema‘uma‘u crater was a rare event, the article said.
It added: “At Kīlauea, this was the largest summit collapse since at least the year 1800, and it included the strongest summit explosions since 1924.
“Only three comparable events have occurred at basaltic volcanoes worldwide in the past 50 years.
“Much larger explosive events have occurred in Kilauea’s past but not since 1790, more than 200 years ago.
“Other aspects of the 2018 activity were also unusual.
“The magnitude-6.9 earthquake that struck Kilauea’s south flank on May 4 was the largest in Hawaii since 1975. The emission rate of sulfur dioxide gas during the main phase of the lower East Rift Zone eruption, at least 50,000 tons per day, was the highest ever measured at Kilauea.
“The lava production rate from fissure 8 also was unusually high for Kīlauea, about three times higher than during the 1955 and 1960 lower East Rift Zone eruptions.
“Such extraordinary events give scientists an opportunity to study aspects of Kīlauea’s behaviour first-hand, to challenge old ideas, and to test new ones.”
Scientists are also puzzled because the summit collapse was not “chaotic”, as might be expected.
The article added: “Instead, the process that left a 500 m (1,600 ft) deep, rubble-strewn pit where Halemaumau had been was remarkably predictable.
“A regular pattern emerged in which seismicity gradually built to a crescendo over 1-3 days, until the caldera floor suddenly dropped several meters in a matter of seconds.
“The pattern repeated dozens of times from May to August 2018. A similar pattern was recognised during summit collapse at Miyakejima volcano, Japan, in 2000.
“Why would such catastrophic events follow a well-behaved pattern?
“Scientists love puzzles, too, and they’re already working to solve this one.”
The volcano yesterday topped the list in the United States Geological Survey’s new report, entitled 2018 Update to the US Geological Survey National Volcanic Threat, with an overall threat level, calculated according to 24 separate criteria, of 253.