Lava Flow Slows as Kīlauea Continues to Erupt

Lava continues to erupt from a single vent in the western wall of Halemaʻumaʻu crater.

As of Tuesday morning, Oct. 19, all lava activity from Kīlauea volcano is confined within the crater in Hawai‘i Volcanoes National Park. Seismicity and volcanic gas emission rates remain elevated.

According to the USGS Hawaiian Volcano Observatory update, the western end of the lava lake within the crater showed a maximum elevation of approximately 2,589 feet above sea level when measured by field crews on Oct. 18, which is a 3-foot increase over the past day and a total increase of about 151 feet since lava emerged on Sept. 29.

The total erupted volume since the beginning of the eruption was estimated to be about 4.2 billion gallons on Oct. 8. The western vent had consistent fountain heights up to 16 feet with occasional bursts up to 49 feet observed by field crews on Oct. 18, According to Tuesday’s update.

The fountain has built a spatter cone with an opening facing east from which lava is flowing into the lake. The central island and several of the smaller eastern islets from the 2020 lava lake are still above the lake surface along with an island of the 2020 western vent rampart in the northwest part of the lake.

The lava lake is not level across its surface due to the location of the vent in the western end. Areas closer to the vent are about 13-16 feet higher in elevation compared to the north and south part of the lake and 39 feet higher than the east end of the lava lake.

Lava surface activity such as crustal foundering is seen on the western end of the lake and north and south of the central island but is no longer observed on the east end of the lake.

No unusual activity has been noted in the Kīlauea East Rift Zone. Ground deformation motion suggests that the upper East Rift Zone—between the summit and Puʻuʻōʻo—has been steadily refilling with magma over the past year. SO2 and hydrogen sulfide (H2S) emissions from Puʻuʻōʻō were below instrumental detection levels when last measured on Jan. 7, 2021.

Sulfur dioxide (SO2) emission rates remain high, with a preliminary emission rate for Oct. 17, 2021, of approximately 2,700 tonnes per day. Summit tilt was slightly deflationary over the past 24 hours.

This new eruption at Kīlauea’s summit is occurring within a closed area of Hawai’i Volcanoes National Park. Therefore, high levels of volcanic gas are the primary hazard of concern, as this hazard can have far-reaching effects downwind. Large amounts of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are continuously released during eruptions of Kīlauea Volcano.

As SO2 is released from the summit, it reacts in the atmosphere to create the visible haze known as vog (volcanic smog) that has been observed downwind of Kīlauea. Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock. For more information on gas hazards at the summit of Kīlauea, click here.  Vog information can be found here.

Additional hazards include Pele’s hair and other lightweight volcanic glass fragments from the lava fountains that will fall downwind of the fissure vents and dust the ground within a few hundred meters (yards) of the vent(s). Strong winds may waft lighter particles to greater distances. Residents should minimize exposure to these volcanic particles, which can cause skin and eye irritation.