The observatory and Hawaii’s emergency management agency said late Monday that the eruption, which began in the morning, had paused about 12 hours later, but it warned that “activity in the region remains dynamic and could change quickly.”

The U.S. Geological Survey (USGS) said lava had been “fountaining” from half-mile-long fissures, with volcanic gases blowing downwind. Scientists had been monitoring the volcano after increased earthquake activity was recorded at its summit.

“The unpredictability of volcanic eruptions is what makes them hazardous,” a park official, Jessica Ferracane, said on Hawaii News Now, which reported that guests arrived in the area to watch from afar.

The eruption took place in a remote, closed part of the park, the USGS said.

The volcano has erupted dozens of times over the past seven decades, including three times in 2023, spewing lava fountains and bursts of volcanic gas. An eruption that lasted months in 2018 engulfed homes in lava, destroying more than 700 as hundreds of residents evacuated.

Over hundreds of years, the volcano has covered much of its surface with lava flows.

The Hawaiian Volcano Observatory said after the eruption paused that “elevated volcanic gas emissions” continued and that it would continue to monitor as the eruption could resume.

A hazard during Kilauea eruptions can be volcanic smog, or vog — a noxious smog formed when sulfur dioxide coming out of eruption vents interacts with oxygen and water vapor in the air.

Hawaii’s aboveground volcanoes formed over the course of the past 5 million years as the Pacific plate drifts over a hot spot in Earth’s mantle.