Mauna Loa, the world’s largest active volcano, has erupted for the first time in nearly four decades and civil defense officials Monday warned residents on Hawaii’s Big Island to stay alert even though there doesn’t appear to be any immediate danger.
“Lava flows are not threatening any downslope communities,” the U.S. Geological Survey said in its most recent update.
Still, the agency warned, “the early stages of a Mauna Loa rift zone eruption can be very dynamic, and the location and advance of lava flows can change rapidly.”
The eruptions began late Sunday night after a series of fairly large earthquakes, said Ken Hon, the scientist-in-charge at the Hawaiian Volcano Observatory.
“Typically, Mauna Loa eruptions start off with the heaviest volume first,” Hon told The Associated Press. “After a few days, it starts to calm down a little bit.”
It could take the lava weeks or months to reach the county seat of Hilo or other towns on the east side of the island, scientists said. But the 200,000 people potentially in harm’s way is more than double the population of 38 years ago when Mauna Loa last erupted.
“We don’t want to try and second-guess the volcano,” Hon said. “We have to let it actually show us what it’s going to do and then we inform people of what is happening ASAP.”
Most of the people on the island live west of the volcano in the city of Kailua-Kona, which has about 23,000 people, and Hilo to the east, which has some 45,000 residents.
There are an estimated 5,000 people who live in several subdivisions south of the volcano — and those are the residents officials are most concerned about.
Mauna Loa, which is located in Hawaii Volcanos National Park erupted at 11:30 p.m. local time Sunday, according to the USGA. It was the first eruption since 1984, according to its Hawaii Volcano Observatory daily update.
The eruption began at the summit in Moku‘ weoweo and soon spread to what is known as the Northeast Rift Zone “where fissures are feeding several lava flows.”
The recent eruption followed weeks of warnings from officials that a blast was imminent following a spike in earthquakes at the volcano’s summit and that Big Island residents should be prepared to evacuate if necessary, NBC affiliate KHNL of Hawaii reported.