Lava fountaining resumed this morning at the summit of Kilauea as a new eruptive episode began inside Halemaumau crater, according to the Hawaiian Volcano Observatory.

The U.S. Geological Survey said Episode 43 of lava fountaining began at 9:17 a.m. at the summit vent within Hawaii Volcanoes National Park. The volcano remains at alert level watch with an aviation color code orange, indicating an ongoing eruption that could produce volcanic ash emissions hazardous to aircraft.

HVO scientists said early lava fountains were reaching about 50 to 60 feet above the vent, though activity typically intensifies shortly after an episode begins.

“Peak fountaining occurs one to two hours after onset and typically reaches 500 to 1,500 feet above ground level, with plumes up to 10,000 to 25,000 feet above mean sea level,” the observatory said in a volcanic notice for aviation.

Ground-level sensors near the eruptive vents show light and variable winds around the summit. HVO said those conditions could cause volcanic gases and airborne volcanic fragments to disperse unpredictably from Halemaumau.

The eruption is currently confined to Halemaumau crater within Kilauea’s summit caldera, known as Kaluapele. Lava flows associated with the eruption have remained within the crater and on the southwest side of the summit caldera, the observatory said.

Volcanic gas emissions are a continuing concern during eruptive episodes. Water vapor, carbon dioxide and sulfur dioxide are released during eruptions, and sulfur dioxide can react in the atmosphere to create volcanic haze known as vog, which can cause respiratory and other health problems downwind.

Lava fountains also generate tephra — small glassy volcanic fragments that can include ash, pumice, scoria and strands known as Pele’s hair. Heavier fragments generally fall close to the vents, while lighter particles may be carried farther by wind. These particles can irritate the skin, eyes and respiratory system.

The Hawaiian Volcano Observatory also warned of hazards around the rim of Halemaumau crater, including cracking, slumping and small landslides that can expose hot or molten material. The crater rim area has been closed to the public since 2007 because of these dangers.

Since Dec. 23, 2024, Kilauea’s summit has experienced dozens of short-lived lava fountaining episodes. HVO said most have lasted a day or less before activity subsides.

Scientists continue to closely monitor the eruption and will issue additional notices if conditions change.