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USGS Volcano Notice for Aviation - DOI-USGS-HVO-2025-08-23T10:15:31+00:00
| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20250823/1323Z) |
| (3) Volcano: | Kilauea (VNUM #332010) |
| (4) Current Color Code: | ORANGE |
| (5) Previous Color Code: | ORANGE |
| (6) Source: | Hawaiian Volcano Observatory |
| (7) Notice Number: | 2025/H373 |
| (8) Volcano Location: | N 19 deg 25 min W 155 deg 17 min |
| (9) Area: | Hawaii |
| (10) Summit Elevation: | 4091 ft (1247 m) |
| (11) Volcanic Activity Summary: |
Episode 31 of the ongoing Halemaʻumaʻu eruption ended abruptly at 2:52 a.m. HST on August 23 after 12.6 hours of continuous fountaining. The north vent stopped erupting at approximately 2:52 a.m. HST marking the end of episode 31. The south and intermediate vents stopped erupting earlier at approximately 12:40 a.m. and 2:46 a.m. HST. Lava fountains from the north vent reached up to 325 ft (100 m) and sustained this height during most of this episode. Fountains from the south and intermediate vents remained small, less than 33 feet (10 meters) for most of the time, but the intermediate vent fountains increased to 60-100 ft (20-30 m) by the evening of August 22. Approximately 10,900,000 cubic yards (8,400,000 cubic meters) of lava were erupted at an average of 240 cubic yards per second (185 cubic meters per second) during the fountaining phase. Lava flows from this episode covered more than 75% of the floor of Halemaʻumaʻu within the southern part of Kaluapele (Kīlauea caldera) and may continue to exhibit slow movement or incandescence as they cool and solidify over the coming days. Voluminous fountaining was preceded by continuous spattering in the north vent that began at approximately 8:30 a.m. HST and continued to increase in intensity until 11:45 a.m. HST, when sustained lava overflows began. During this period, a cone was built inside the north vent sealing off part of the old vent. Fountaining in the north vent began increasing significantly at 2:04 p.m. HST accompanied by deflationary tilt and increasing tremor. The north vent transitioned to an arcuate fountain approximately 100 feet (30 meters) high feeding multiple lava streams at 2:18 p.m. HST corresponding with the change to steep deflation and high tremor. Sometime around 4-5 p.m. HST, low spatter fountains began to feed a small flow from the south vent. At 7:23 p.m. HST, a new intermediate vent opened up in the area of glowing cracks between the north and south vents. Volcanic gas emissions have greatly decreased since the end of the episode. The Uēkahuna tiltmeter (UWD) recorded about 22 microradians of deflationary tilt during this episode. The end of the eruption was coincident with a rapid change from deflation to inflation at the summit and a decrease in seismic tremor intensity. Most episodes of Halemaʻumaʻu lava fountaining since the eruption started on December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days.
No changes have been detected in the East Rift Zone or Southwest Rift Zone. Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park. |
| (12) Volcanic cloud height: | Unknown |
| (13) Other volcanic cloud information: | Sulfur dioxide emission rate is typically 1,200-1,500 tonnes/day between eruptive episodes |
| (14) Remarks: | Hazard Analysis: This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/ Another hazard closer to the vent is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity and can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments including Peleʻs hair, volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1-2 miles (1-3 kilometers) of the eruptive vent(s) with the highest concentrations downwind of the vent(s). Pumice and other volcanic fragments have fallen on Highway 11 west of Hawaiʻi Volcanoes National Park depending on wind and eruption conditions. Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf Hawaiian lava flows generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera. 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's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007. |
| (15) Contacts: | |
| (16) Next Notice: | HVO continues to closely monitor Kīlauea and will issue a VAN/VONA at the start of the next eruptive episode. If possible, HVO will also issue a Status Report beforehand at the onset of low-level precursory activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates More Information:
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