An overview of the lava lake within Halema‘uma‘u crater, at Kīlauea Volcano’s summit, taken on May 25. Kīlauea’s summit collapse in 2018 deepened Halema‘uma‘u crater by over 500 meters (1640 feet). The eruption that began the evening of December 20, 2020, has filled approximately 229 m (751 ft) of the base of Halema‘uma‘u crater, which is more than the height of the Space Needle in Seattle, Washington. USGS photo by K. Mulliken.
Kīlauea Volcano is no longer erupting. Observations indicate that the eruption in Halema‘uma‘u at the summit of Kīlauea Volcano has paused. This morning, May 26, the lava lake is 229 m (751 ft) deep and is stagnant across its surface. Within the past 48 hours, no active lava was observed in webcam images of the Halema‘uma‘u crater lava lake surface. Field crews on May 25 did not observe any signs of lava lake activity, and reported no signs of recently active surface lava. Sulfur dioxide emission rates remain slightly elevated.
HVO will issue a Volcano Activity Notice (VAN) lowering the Volcano Alert Level for ground based hazards from WATCH to ADVISORY and the Aviation Color Code from ORANGE to YELLOW. HVO continues to monitor Kīlauea Volcano closely for additional signs of changes in activity.
Summit Observations: The most recent sulfur dioxide (SO2) emission rates, measured on May 23, were 100 tonnes per day, continuing a trend of decreased emission rates that began in mid-April. The SO2 emission rates are now nearly at levels associated with the recent non-eruptive period from late 2018 to late 2020 (less than 50 tonnes per day), and are significantly lower than emission rates that averaged over 800 tonnes per day from mid-February to mid-April. Summit tiltmeters recorded slight but continuous deflation over the past 24 hours. Seismicity remains stable, with elevated tremor.
East Rift Zone Observations: No unusual activity noted in the region. Geodetic monitors indicate that the summit and upper East Rift Zone—between the summit and Puʻuʻōʻō—is refilling at rates similar to those measured over the past 2 years and before the December 2020 eruption. SO2 and hydrogen sulfide (H2S) emissions from Puʻuʻōʻō were below instrumental detection levels when last measured on January 7 2021.
Halemaʻumaʻu Lava Lake Observations: Observations indicate that the eruption in Halema‘uma‘u at the summit of Kīlauea Volcano has paused. It is possible that the Halema‘uma‘u vent could resume eruption or that Kīlauea is entering a period of quiescence prior the next eruption. The total depth of the lake is 229 m (751 ft) as measured by a continuous laser rangefinder on the western portion of the lake near the west vent area, and is unchanged since May 11, 2021. The total volume of the lake is approximately 41.2 million cubic meters (11 billion gallons). Within the past 48 hours, no active lava was observed in webcam images of the Halema‘uma‘u crater lava lake surface. Field crews on May 25 observed no signs of lava lake activity, no incandescence, and no signs of recently active surface lava. Small incandescent spots visible in thermal webcam imagery since May 23 persist, but have become much fainter. The lake’s surface is covered by stagnant and solidified lava crust.
Near-real time webcam views of the lava lake can be found here: https://www.usgs.gov/volcanoes/kilauea/webcams.
Hazard Analysis: Levels of volcanic gas (SO2 and CO2) can remain locally hazardous even though Kīlauea is no longer erupting. Sulfur dioxide (SO2) gas emissions have greatly decreased. However, local concentrations of sulfur dioxide (SO2) or hydrogen sulfide (H2S) may persist in downwind areas, and residents may from time to time notice odors of these gasses. Significant hazards also remain around Halemaʻumaʻu from crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. Even with decreased effusion rates and no signs of lava lake activity, conditions around Halema‘uma‘u crater remain hazardous.
Vog information can be found at https://vog.ivhhn.org/.
The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea’s seismicity, deformation, and gas emissions, and maintains visual surveillance of the summit and the East Rift Zone.
Beginning May 27, 2021, HVO will issue weekly Kīlauea Volcano updates instead of daily updates, and additional messages as needed.