LOS ANGELES, Dec. 23 -- Kilauea, one of the world's most active volcanoes, started erupting again early Monday morning on Hawaii's Big Island, the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory said.

Elevated earthquake activity beneath the volcano's summit began at approximately 2:00 a.m. local time. By 2:30 a.m. local time, the USGS Hawaiian Volcano Observatory observed eruptive activity in Kilauea summit webcam images, indicating that an eruption has commenced within Halemaʻumaʻu and the summit caldera in Hawaii Volcanoes National Park, according to a news release from the agency.

The USGS Hawaiian Volcano Observatory said it is elevating Kilauea's volcano alert level from advisory to warning and its aviation color code from yellow to red as this eruption and associated hazards are evaluated.

The opening phases of eruptions are dynamic, said the agency, adding that the activity is confined to the summit caldera and the hazards will be reassessed as the eruption progresses.

The USGS noted that high levels of volcanic gas -- primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) -- are the primary hazard of concern, as this hazard can have far-reaching effects down-wind.

It's the second time the volcano has erupted this year. The most recent Kilauea eruption was in September.

Hawaii Volcanoes National Park said in a Facebook post that "the new eruption at the summit of Kilauea volcano is drawing thousands of visitors to Hawaii Volcanoes National Park eager to see new erupting lava by day and the lava glow after dark."

"This new eruption is viewable from almost all open areas around the caldera," said the park, adding that the park remains open 24 hours a day.

The park also warned tourists that "while an eruption is an exciting experience, keep in mind you are observing a sacred event" and reminded the public to stay safe as "volcanic eruptions can be hazardous and change at any time."

  - Xinhua