Hawaii's Mauna Loa, the world’s largest active volcano, has begun erupting for the first time since the 1980s, prompting authorities to put emergency crews on alert.

The volcano began spewing lava and ash late Sunday. The U.S. Geological Service (USGS) said Monday the lava is contained within the summit and does not currently threaten residents living in the area. However, it said those living downslope could experience ashfall and volcanic gases.

The National Weather Service in Honolulu said up to 6 millimeters (0.25 inches) of ash could accumulate in some areas.

The last time the volcano, which is situated on Hawaii’s Big Island, erupted was in 1984. That eruption produced lava flows that reached within about 8 kilometers (5 miles) of Hilo, the island’s largest city.

Officials said Monday there is no indication that the current eruption will lead to a lava flow that threatens populated areas.

"At this time, it's not a time to be alarmed," Big Island Mayor Mitch Roth said.

Hawaii's Emergency Management Agency said about half of all recorded eruptions of Mauna Loa had been confined to the summit.

Authorities have not issued any evacuation orders for the area around the volcano. However, they have opened two shelters on the island as a precaution for those who do not want to stay in their homes.

The USGS urged people to review preparedness procedures, noting that the volcano’s course can change quickly.

“Based on past events, 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,” USGS said in a statement on their website.

Mauna Loa rises 4,169 meters (2.6 miles) above the Pacific Ocean and is part of a chain of volcanoes on Hawaii’s islands. The neighboring Kilauea volcano erupted in a residential neighborhood in 2018, destroying hundreds of homes. (KB/VOA)