World's largest active volcano, Mauna Loa, erupts in Hawaii

The world's largest progressive volcano has erupted successful Hawaii for the archetypal clip successful astir 4 decades, officials said.

Mauna Loa erupted astatine 11:30 p.m. section clip Sunday (4:30 a.m. ET Monday), the U.S. Geological Survey said. It was the archetypal eruption since 1984, according to its Hawaii Volcano Observatory daily update.

The eruption began successful Moku'āweoweo, the acme caldera of Mauna Loa, wrong Hawaii Volcanoes National Park, the bureau said, arsenic it upgraded the volcano's alert level from an "advisory" to a "warning."

"At this time, lava flows are contained wrong the acme country and are not threatening downslope communities," the USGS said successful a quality release. "Winds whitethorn transportation volcanic state and perchance good ash and Pele's hairsbreadth downwind," it said, referring to a benignant of lava.

Residents astatine hazard from Mauna Loa lava flows were advised to "review preparedness and notation to Hawai'i County Civil Defense accusation for further guidance."

"Based connected past events, the aboriginal stages of a Mauna Loa eruption tin beryllium precise dynamic and the determination and beforehand of lava flows tin alteration rapidly," the bureau warned. It said that if the eruption remains successful Moku'āweoweo, lava flows would astir apt beryllium contained. "However, if the eruptive vents migrate extracurricular its walls, lava flows whitethorn determination rapidly downslope," it said.

The astir caller eruption followed weeks of warnings from officials that an eruption was imaginable fixed a caller spike successful earthquakes astatine the volcano's acme and that residents of the Big Island should beryllium prepared to evacuate, NBC affiliate KHNL of Hawaii reported.

The USGS antecedently said that "heightened unrest" began successful mid-September, erstwhile earthquakes beneath the acme accrued from 10 to 20 per time to 40 to 50 per day. That unrest prompted Hawaii Volcanoes National Park to adjacent the acme backcountry until further notice, it reported.

Ken Hon of the Hawaiian Volcano Observatory had said the earthquakes chiefly occurred owed to the value of the upland dilatory sliding toward the ocean, KHNL reported.

In the weeks starring up to the eruption, residents had gathered successful the towns of Pahala and Ocean View successful October to sermon their concerns astir region officials' plans if an eruption were to unfold, it reported.

Hawaii's civilian defence bureau besides held meetings crossed the land to assistance residents hole for a imaginable emergency, The Associated Press reported.

The volcano, whose sanction means "Long Mountain," covers fractional of the island, according to the USGS. Prior to its astir caller eruption, it erupted 33 times, opening successful 1843, making it among the world's astir progressive volcanoes. It is 1 of six volcanoes successful the authorities of Hawaii, according to the agency.

About fractional of those past eruptions remained successful the acme portion —which rises astir 55,700 feet supra its base, according to the USGS — and astir others migrated from the acme into 1 of the rift zones, producing lava flows that covered wide regions connected the volcano's little slopes.

"Hawaiian lava flows person seldom caused quality fatalities, but they tin origin extended harm by covering, burning, and crushing thing successful their paths, oregon starting secondary fires," according to the agency, which adds that interactions betwixt h2o and lava "can besides sometimes beryllium explosive successful coastal environments."

When the volcano's northeast flank erupted successful 1984, residents had clip to prepare, arsenic the eruption occurred successful a "higher slope area" and took longer for the lava to question towards the municipality of Hilo — the municipality located successful the island's northeast portion and location to the Hilo International Airport — erstwhile Hawaii County Mayor Harry Kim, who was the civilian defence head astatine the time, told KHNL. That eruption lasted 3 weeks, according to the USGS.