Updated Nov 28, 2022 - Energy & Environment

World's largest active volcano starts to erupt in Hawaii

Photo of the Mokuʻāweoweo Caldera from the Northwest Rim of the Mauna Loa volcano.

The north rim of Mokuʻāweoweo, the summit caldera of Mauna Loa volcano on Nov. 28. Photo: USGS Hawaiian Volcano Observatory

The world's largest active volcano has started to erupt for the first time since 1984, local authorities said Monday.

Driving the news: Hawaii's Mauna Loa volcano — located on the Big Island — began erupting late Sunday night, the U.S. Geological Survey said.

  • As of Monday midday, the Geological Survey said lava from the eruption was flowing down one side of the volcano and was not threatening any downslope communities, though harmful volcanic gas — and possibly fine ash and glass fibers — could be carried downwind.

State of play: USGS warned on Sunday that "residents at risk from Mauna Loa lava flows should review preparedness and refer to Hawai'i County Civil Defense information for further guidance."

  • "Based on past events, the early stages of a Mauna Loa eruption can be very dynamic and the location and advance of lava flows can change rapidly," USGS said.

The big picture: In October, officials in Hawaii started to warn residents of the Big Island that Mauna Loa may be signaling that it could erupt, AP reports.

Flashback: The 1984 eruption began suddenly after three years of increasing earthquake activity beneath the volcano, per USGS.

  • In 1950, Mauna Loa erupted and within three hours, lava flows had crossed the main highway on the west coast of Hawaii.

Go deeper... How some volcanoes erupt with little warning

Editor's note: This is a developing story. Please check back for updates.

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