The eruption that began at Kīlauea summit on September 10 has ended. Lava supply to the vents on the downdropped block in Kīlauea ‘s summit caldera ceased yesterday, September 16, based upon visual and geophysical observations. Sulfur dioxide (SO2) emissions have decreased to near pre-eruption background levels.
Accordingly, the USGS Hawaiian Volcano Observatory (HVO) is lowering the Volcano Alert Level for ground-based hazards from WATCH to ADVISORY and the Aviation Color Code from ORANGE to YELLOW.
During the morning of September 16, HVO field crews reported that active lava was no longer flowing onto Halemaʻumaʻu crater floor and was restricted to a ponded area north of the vents on the downdropped block. They observed lava spattering at the vents cease at approximately 11:15 am yesterday, September 16, and webcam views show the ponded lava stagnant by around noon. Overnight webcam views showed incandescence across the eruption area as lava erupted over the past week continues to cool. These observations are supported by geophysical data which shows that eruptive tremor (a signal associated with fluid movement) in the summit region decreased over September 15 and 16 and returned to pre-eruption levels by 5 p.m. HST on September 16. Over that period, mild inflation has been recorded at summit tiltmeters. Sulfur dioxide (SO2) emissions have also decreased to near background levels, and were measured at a rate of 800 tonnes per day yesterday, September 16.
More eruption information on the September 2023 Kīlauea summit eruption is available at: https://www.usgs.gov/volcanoes/kilauea/recent-eruption.
There remains the potential for eruptive activity to resume in the near future at or near the summit of Kīlauea with little or no warning.
HVO continues to closely monitor Kīlauea for signs of renewed activity. Should volcanic activity change significantly, a new Volcanic Activity Notice will be issued.
Hazards are still present on Kīlauea and are described below. Residents and visitors should stay informed and follow County of Hawai‘i and Hawaiʻi Volcanoes National Park guidelines.
For more information about the meaning of volcano alert levels and aviation color codes, see https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes