Lava Lake Rises Another 7 Feet Over 24-Hour Span

The lava lake continues to rise since Kīlauea began erupting last week. As of this morning, Oct. 6, 2021, all lava activity is confined within Halemaʻumaʻu crater in Hawai‘i Volcanoes National Park. Seismicity and volcanic gas emission rates remain elevated.

Over the past 24 hours, US Geological Survey Hawaiian Volcano Observatory reported the lake within Halemaʻumaʻu crater has risen approximately 7 feet, with a total rise of 102 feet since lava emerged on Sept. 29, 2021.

Lava continues to erupt from two vents; one along the floor and one in the western wall of the crater. According to USGS HVO, the west vent continues to have the most vigorous fountain with sustained lava fountain heights of about 49 feet. The lava lake has risen above the base of the vent and the fountain has built a spatter rampart around most of it.

Another vent continues to be active in the southern part of the lake with lava fountain heights averaging 10 feet. Due to the location of vents, the lava lake is not level across its surface.

Areas closer to vents in the west and south part are about 3–7 feet higher in elevation compared to the north and east end of the lava lake. Crustal foundering, a process by which cooled lava crust on the lake surface sinks into the hot underlying lake lava, is observed on the active surface of the lava lake. The active lava lake surface is perched 3 feet above a 66-foot-wide ledge that extends outward to the Halemaʻumaʻu crater wall.

The total thickness of lava filling Halemaʻumaʻu is now 840 feet with a lake surface elevation of approximately 2,539 feet above sea level.

Sulfur dioxide (SO2) emission rates remain high, with a measured emission rate of approximately 6,000 tonnes per day on Oct. 5, 2021. Seismicity remains elevated but stable. Summit tiltmeters continue to record deflationary tilt.

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.

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. see: . 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. 

Other significant hazards also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. This underscores the extremely hazardous nature of Kīlauea caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since early 2008.