Mauna Loa is erupting for the first time in nearly 40 years, forcing closures and putting Hawaii residents on high alert.
The U.S. Geological Survey's Hawaiian Volcano Observatory said Monday that the eruption continued in the Northeast Rift Zone, with three fissures erupting and lava shooting between 100 and 200 feet into the air.
The observatory cautioned that lava flows could continue to travel downslope.
"There is no active lava within Moku'āweoweo caldera, and there is no lava erupting from the Southwest Rift Zone. We do not expect any eruptive activity outside the Northeast Rift Zone. No property is at risk currently. There is a visible gas plume from the erupting fissure fountains and lava flows, with the plume primarily being blown to the Northwest," it said.
The eruption began on Sunday night following a series of large earthquakes.
The hours-long eruption prompted the Hawaii Department of Land and Natural Resources Division of Forestry and Wildlife to close the Mauna Loa Forest Reserve and the Kipuka ‘Ainahou Nēnē Sanctuary for at least 90 days, in addition to some other areas.
Hawaii County Mayor Mitch Roth declared a state of emergency due to the threat of imminent disaster early Monday.
While no mandatory evacuations were ordered, he said community evacuations may become necessary and several shelters were opened.
The Hawaii Department of Health alerted the public about "voggy conditions," including potential air quality hazards across the state. Residents were advised to reduce outdoor activities.
"Air quality remains normal, however, the eruption could cause #vog, ash in the air, and levels of sulfur dioxide to increase and fluctuate. Conditions may change rapidly," it tweeted on Monday. Vog is volcanic smog.
Another threat includes glass particles called "Pele's hair" and "Pele's tears," after the Hawaiian goddess of volcanoes. The bits can be sharp and as long as a few inches.
According to KHON 2, Southwest Airlines canceled its flights to Hilo on Monday after a volcanic ash advisory.
As the lava flow is not posing any threats to Hawaii County communities, Gov. David Ige said there is currently no reason for anyone to change their travel plans to the Big Island.
Should lava from Mauna Loa, the world's largest active volcano, reach neighborhoods on the eastern side of the Big Island, it could take as long as a week or more.
It last erupted in 1984, with lava stopping just a few miles from Hilo.
The Associated Press contributed to this report.