The governor of Hawaii, David Ige, has declared a state of emergency and mandatory evacuation as a result of the eruption of the Pu?u ???? vent of the Kilauea volcano. Kilauea is located on the south-east side of the big island of Hawaii. An estimated 1,700 people living in the possible path of the lava flow have been ordered to evacuate.
The eruption was preceeded by hundreds of earthquakes, the largest of which was magnitude 5 on the Richter scale. However, there was a delay of almost a day between the largest earthquake and the eruption, and the decreasing frequency of quakes on Thursday inspired hopes the immediate danger may have passed. Unfortunately, not only has a large amount of lava flowed from the vent, but it is heading towards habitation, rather than into the national park or nature reserve where most past flows have gone.
Even before the earthquakes, there were signs Pu?u ?O ?? might have something in store. The Halema‘uma‘u crater's lava lake has been rising since late March.
Halema‘uma‘u lava lake from the observation deck of the Jaggar Museum. Volunteer Ranger Janice Wei. US National Parks Service.
On April 22 lava bubbled over the rim in the largest outflow for 10 years.
Kilauea is among the world's most active volcanoes, but not usually one of its most dangerous. As the governor's proclamation notes, Pu?u ???? vent alone has been erupting since 1983. It's the same volcano that added two acres of land to Hawaii last year when lava flowed into the sea and cooled.
The year before that it created some spectacular lava flows that harmed only forest.
Kilauea is a shield volcano that produces low-silica lava, and therefore seldom explodes catastrophically. However, the downside of low silica lava flows is their much greater reach, so when the direction in which the lava spills takes it towards houses, problems can arise.
In this case, the Leilani Estates are potentially in line to be covered by the lava, or burnt by the forest fires it is setting off as it travels.
Lava has already flown into the streets of Leilani, and there are reports it got under Highway 130 and is coming up through cracks opened by the earthquakes. The proclamation notes: “The current flow also exhibits characteristics similar to the 1960 Kapoho eruption, which caused significant damage to public and private property.”
Nevertheless, even the worst-case scenarios with Kilauea are small compared to the potential of its near neighbor Mauna Loa, the largest single volcano on the planet. Mauna Loa has not erupted since 1984, an unusually long time for this sort of volcano, and long delays usually end in particularly large explosions.